We have just moved into the new house we built about a year and a half ago. For our wiring we did everything top knotch and to code. For the kitchen countertops we installed GFCI recepticals (14) at every outlet. Outlets to the dishwasher and trash compactor are on the same circuits but are not GFCI protected. During the last month one of the countertop GFCIs has been popping off, sometimes with nothing plugged into it. It was my belief that the GFCI works by comparing the current in (hot wire) with the current out (neutral wire) and if there is more than 6ma difference; then the GFCI pops. With nothing plugged in, I don’t know what could be leaking the current. We have installed two more GFCI outlets in the box and all three pop off the same way for no perceived reason. I am tired of this troubleshooting by substitution. All of the GFCI outlets are pigtailed to the circuit wires and are connected only on their line side. I am at my wits end trying to think why this one GFCI continues to pop. Even after it disconnects itself, we occasionally hear it trying to turn itself off again. This does not happen instantaneously. The outlet will generally work for a few hours between pops.
Any ideas would be appreciated.
Replies
You should post this in the "Energy, Heating & Insulation" section
>> You should post this in the "Energy, Heating & Insulation" sectionWhat folder was it in when you replied to it?
14 GFCI receptical?
You did not need one in each location. You could have use one, and then regular recpts. downstraem, and achieved the same protection and compliance.
For the one that is tripping. Take it out and put in a standard grounded outlet. The GFCI up stream will protect the new receptical.
Dave
In order to get protection, if you replace the GFCI with a regular receptacle you must connect the source to the LOAD side of the previous GFCI. I don't know if or how this will affect any GFCIs further down the line.
But that won't solve his basic problem.As I read it each one is wiredd individually. NOTHING on the load side, eiter on the load terminals or pluged in.Apparently a batch of bad GFCI's.BTW, I just ran into this in a condo. In fact I posted some question shere to see when kitchen GFCI's where first required. It was after the condo was built so I am assuming the HO did this.On one side of the kitchen there where 3 GFCI's. One on a different circuit, but the other 2 on one cirucit and the first fed the 2nd. On the other side they had a GFCI which feed a regular rect in an applicane garage, then to a double GFCI, The first feed the 2nd and also a recpt over the kitchen desk. That would have worked, but been confusing. However, all of them on that side where wired backwards with the power coming into the load side. Once tripped they would not reset.
I think you summarized pretty well what I was trying to say. I didn't want to have just one GFCI controlling everything so I overdid it with the number I installed and I put all in parallel with nothing attached to the load side of any of them.
The original GFCI in the box worked for over a year before the tripping started. It was about that time when I realized that I had a GFCI in a bathroom which was also downstream of a GFCI breaker. Since it was working well where it was, I replaced it with a regular outlet and used it as the first substitute GFCI in the box I was having trouble with. It continued popping like the original. Next, we bought a new GFCI and it behaves the same in this box. I believe all three are from different manufacturers so I am discounting a bunch of bad GFCIs.
After posting my problem last night, I realized that this box is just off to the side of where the dishwasher is. We will try to monitor the performance about when it pops in relation to operating the dishwasher to see if moist air from drying might be the culpret. The dishwasher is on its own non-GFCI box. Other than that, I think I might trade boxes with another GFCI which doesn't now have this problem and see what happens.
If all the GFCI's are connected only to their 'line' terminals, with no wires connected to their 'load' terminals, and if one trips with nothing plugged in to it, I don't see any possible conclusion other than a bad GFCI. (Barring something off-the-wall like a bunch of steam getting into that particular outlet on occassion).
Just out of curiosity, are your two countertop receptacle circuits fed by two separate 2-wire w/ground cables or by one 3-wire w/ground cable ?
In answer to your question, the circuits are fed with a 3-wire with ground to a junction box. One hot w/ground feeds the countertop receptacles I am concerned with. The other branches off for the dishwasher, trash compactor, and the vent fan.
Are you sharing neutral with your non GFI dishwasher?
Make sure that the load terminals of the outlet aren't accidentally contacting the side of the box or a ground wire in the box or some such.
Other than that, presumably it's humidity from the DW, or, a long shot -- some sort of magnetic field (fan, microwave, etc) that is affecting the outlet.
PROBLEM SOLVED (I hope!)
Thanks to all of you for your offers to help and things to consider; but I think I found the cause of the GFCI interuptions.
I did not mention that this was the outlet which my wife plugged in her cell phone to charge. To eliminate a possible ground fault in the charger, she unplugged the charger when the phone battery was charged but left the phone on the counter right next to this outlet. The GFCI continued to pop off about once or twice a day. Finally I was frustrated enough to post my initial problem report. After receiving DanH's comment that it is probably some sort of magnetic field which is affecting the recepticle, we started to consider the cell phone. Last night she moved the cell phone close by another GFCI outlet and it has popped twice and the original problem outlet has not popped. To the best of my knowledge, this second outlet had not done that before.
This has been my first experience with this forum. I have been a subscriber to FineHomebuilding for a lot of years and found the information invaluable when we were building my house. I read the excerpts from this forum which are printed in the magazine every month and did not think I would need advice for a problem with my house. I have been surprised at the number of folks who offered help with my concern. Thanks also to whoever placed my problem in the proper section of this forum. I was not aware that there is a specific section for "energy."
Next time anyone of you reads a similar complaint, make sure you ask if there is a cell phone nearby. That will make you a hero to the person with the problem. My problem wasn't with the number of wires coming from the main box or sharing a ground. It was the cell phone.
Thanks again,
--Al
Well, for your sake, I hope your problem is solved, but I can't understand how a cell phone just sitting on a counter could possibly affect the GFCI. Maybe we'll get lucky and a telecommunications engineer can explain, but why would a cell phone not being talked on generate anything other than a completely inconsequential electromagnetic field ? And an incoming call to that phone would have the same electromagnetic energy field everywhere in the house, it couldn't just magically concentrate near where the phone is. I don't get it.
Also, with millions of homes with both GFCIs and cell phones, you'd think this problem would be pretty well known by now. Maybe others have heard of it, but I haven't. What about ham radio operators ? I woud think the signal strength they broadcast at is many orders of magnitude greater (although obviously at different frequencies).
Edited 2/11/2005 9:20 pm ET by r
As I understand it, pardon me if I'm wrong, the charger that served the cell phone was defective. I was thinking about the original post and could only conclude that something being plugged into the GFI was causing the problem. GFIs, once correctly wired, generally are quite insensitive to line side, the side closest to the utility lines, conditions. But then he went on to plainly state state that nothing was plugged into the GFI.The two conditions seemed to be contradictory and a real poser. Instead of diving in where I had little idea of the situation I remained silent and stumped.He could reconfirm his observation that the charger is the cause by plugging it into another GFI and see if it trips it. It could be a defective block transformer or mechanically damaged charge base but, given that this is a kitchen and knowing how things go in family kitchens, I would suspect that the charger or transformer block got dropped into a sink full of water.
Maybe I'm misunderstanding him, but he says "she unplugged the charger when the phone battery was charged but left the phone on the counter right next to this outlet", and the outlet was fine at that time, but tripped later. Or have I got that wrong ?
Now I'm kicking myself for not suggesting this earlier: Al, do you have a GFCI tester ? (Mine is a Sperry, yellow with 3 lights and a test button. Or a similar one). If so, I would plug it in to each of your GFCIs and push the test button. Also, plug it into the non-GFCI outlets that you say are also on the same circuit and push the test button. We may find that everything isn't wired as you think it is.
Ever used your cell phone while you're sitting at your computer?
Even 2 or 3 feet away, you will hear buzzing on your speakers and on a CRT monitor you can even see some distortion.
These little critters put out a significant amount of EMI 'cause of the frequency they use. That's why they don't allow them in critical care areas of hospitals-they foul up the monitoring systems.
So, it's reasonable to think that the cell phone did it-especially with the effect "transported" to a different GFI.
Though I'd certainly go around with a GFI tester and see if they're not reverse wired or something.
Steve
Edited 2/11/2005 9:44 pm ET by Steve
The magnetic field from cell phones is also the reason they need to be turned off below 10,000 feet on all commercial flights. The field is so strong that it interferes with the avionics. If you think of it, the next time you're driving and the phone rings, hold it with the antenna toward your car stereo to see if it make a bunch of noise. Even while playing a cassette or disc.
"I cut this piece four times and it's still too short."
Correct-sort of:
That's why the FAA says no. But the FCC is also concerned about a cell phone in the air which will be able to see too many towers, unlike one on the ground that will see only one to three. That will potentially confuse the "hand-offs" that the cellular system is designed for and even bring the whole system down.
And, if you read your owner's manual in your car, it actually warns against cell phones without antennas mounted on the outside of the car. It can conceivably confuse the onboard computers that control the engine, etc.
Of course, that's why the idiot in front of me is on the phone, and not going on the green light. And the idiot behind me just hit my bumper.
And I sure as heck don't want to be sitting in the middle seat of an airplane with both idiots next to me yakking away for an entire flight.
And I'm starting to sound like Andy Rooney...
Steve
With the cell sites positioned six miles apart for any one company's system, it shouldn't be a problem. However, with the positioning of towers from the competing systems and the cooperation between them, I can see how there could be a half-dozen towers being picking up one phone's signal.
"I cut this piece four times and it's still too short."
My guess is that when the cell phone broadcasts (which it does from time to time even when "on hook", just to report where it is) the electric field produced by the phone is sufficient to get into the toroidal transformers in the GFCI and confuse them.
DanH,
I didn't think I would create such an avalance of replies when I said I think that my problem is solved. I don't understand what you said; but I figure that my wife's cell phone somehow transmits to the nearest cell tower to say if the phone is on or not. And that transmitting has somehow induced a voltage/current into the GFCI outlet.
Maybe someone else reading this forum might try placing your cell phone next to a GFCI and see if you can duplicate my problem and post the results on this forum. The cell phone had been stood up with the antenna up on the countertop next to the GFCI. The GFCI had been tripping about once a day or so and it finally became too much of an inconvenience so I posted my problem report. After the first trip, we occasionally heard noises of the GFCI trying to trip again even though the outlet was already off. I could not duplicate the snap in the GFCI by pushing the RESET button again.
In case anyone is wondering, I have Verizon service and my wife uses a Motorola phone. The Nokia and Samsung phones she had before also popped the GFCI but she didn't get fed up with the GFCI outlet tripping until recently. So it wasn't my problem until she complained.
It is not a problem with the charger because we did not move the charger to the outlet which tripped two times in the last day. The phone was just placed next to the GFCI outlet.
Again, thanks for the concern.
--Al
I can't understand how a cell phone just sitting on a counter could possibly affect the GFCI. Maybe we'll get lucky and a telecommunications engineer can explain, but why would a cell phone not being talked on generate anything other than a completely inconsequential electromagnetic field ?
The phone will periodically switch on the transmitter and send an "I'm here" message to the nearest cell site. Remember that cellphones can take incoming calls; the network needs to know where the phone is at all timesso it knows how to route the calls.
You hear stories in the news sometimes of how a criminal's location was tracked down through his cellphone, even though he never talked on it. This is the reason the authorities are able to do it.
the transmit power the phone uses is dependent on the signal level they receive from the tower. if it receives a weak signal, it will transmit at a high power, under the assumption that it will take a strong signal from the phone in order for the tower to hear it. With the phone indoors in a weak reception area, it could be putting out maximum power when it "wakes up" (I always chuckle at the "community activists" who resist cell tower installation because of a worry about radiation risks, when in fact it ends up causing more radiation due to the fact that the phone themselves must radiate more, and the phones are located far closer to people than the cell site transmitter on the top of a tall tower).
I had an old TDMA phone which I could predict when it was going to ring. When it woke up and did its message exchange with the cell site prior to the incoming call, it would screw up the car radio a few seconds before it would actually ring.
Europeans are very familar with the disctive cadence that their GSM-system phone occassionally cause in audio equipment. i remember there was great concern when the system was first deployed that hearing-aid users would hear this noise constantly in European cities.
I read BarryO's comments after I posted my last. He said that the weaker the signal received, the stronger the signal the cell phone will put out. I live out in the woods at the edge of the Verizon signal. Occasionally we lose signal at our house. I cancelled my first cell phone provider because I could not get a signal at my house. So all of you with 3 or 4 bars at your house need not take me up on my challenge to see if you can duplicate my problem.
----Al
Thanks to you and Dan for the technical info. I knew someone smart would provide the detail.
But I have to remain in the skeptical camp. With the millions of cell phones and millions of GFCIs living in close proximity to each other for all these years, you would think this would be a totally well documented problem by now. Aren't there hundreds of thousands, if not millions, of households tht right now have cell phones sitting on kitchen counters right next to GFCIs ?
I wish Al had responded to my GFCI tester suggestion.
The GFCi's come with tape over the load terminals.So unless that was removed it is very clear that it does not feed any downstream outlets."With the millions of cell phones and millions of GFCIs living in close proximity to each other for all these years, you would think this would be a totally well documented problem by now. Aren't there hundreds of thousands, if not millions, of households tht right now have cell phones sitting on kitchen counters right next to GFCIs ?"2 things here.First the effective power decreases by the square of the distance. So moving it just a few inches is probably enough not to cause the problem.The other is that they are often that close to GFCI's.I suspect that if they are in the kitchen, which is probably a common location, they are at a desk or a wall outlet that is not GFCI protect. Those are locations that would be out of the work area and not interfer with cooking. And if they happen to be in the cooking area that they are on a shelf that puts them a ft or more away fromthe GFCI.
Bill, you said: "2 things here.
First the effective power decreases by the square of the distance. So moving it just a few inches is probably enough not to cause the problem.
The other is that they are often that close to GFCI's."
WRONG WRONG WRONG. you obviously have no idea how the peak to peak distance effects this situation. radio signals bounce/deflect at predictable angles, and a six-inch peak to peak means that MOVING THE PHONE A FEW INCHES WILLLLLLLLLLL cause the problem!!!!!! That plus the strength of the signal AT THAT PARTICULAR MOMENT. And Cell Phones are RARELY powered up and receiving/transmitting at maximum capacity within a SIX to 12 INCH ARC OF A GFCI RECEPTICAL. Think about it, HOW OFTEN DO YOU LAY YOUR HEAD ON THE KITCHEN COUNTER UNDER THE UPPER CABINETS AND CARRY ON A CONVERSATION? HOW OFTEN ARE YOU WITHIN 12 inches of the bathroom receptical with the phone in full use? and with the FEWEST SIGNAL BARS displaying?????
You speak such things as fact, when they are uninformed conclusions of your own! The Industry (cell phones), UL, and our Federal Government (FCC, CPSC, and other divisions/departments) have independently, and in conjunction with each other done SCIENTIFIC STUDIES on this very issue that dispute you GREATLY. This is WHY it took SO LONG for the UL to begin to conduct the field studies on this KNOWN EFFECT which has been confirmed and documented, read the references I gave you on UL.COM buddy then peruse firstgov.gov for some more HIGHLY informative and i'm quite sure over-your-head publications on this very issue.
"WRONG WRONG WRONG. you obviously have no idea how the peak to peak distance effects this situation. radio signals bounce/deflect at predictable angles, and a six-inch peak to peak means that MOVING THE PHONE A FEW INCHES WILLLLLLLLLLL cause the problem!!!!!!You are confusing Near field therory and Far field therory.And yes I read the whole thing. Unfortuantely.It has been fun playing.But I have to get back to something USEFUL.Just too many things mistaken, backwards, and down right wrong in what you wrote to have to dig through it any more.
r,
You say you had wished I had tried a GFCI tester on all outlets in the circuit. When the problem first arose, we initially suspected the GFCI outlet and the wiring in the box. My wife repeatedly checked out the wiring and even replaced the pigtails to insure nothing was wrong. As I said before we replaced the GFCI outlet twice. A couple of days ago she moved the phone to right next to another GFCI and the problem transferred over to there. Last night she moved the cell phone to 4 feet away from any GFCI and nothing has tripped.
Right now I do not suspect any problem with the GFCIs in our kitchen. When I go to a hardware store, I will check the cost of a GFCI tester. If reasonable, I may buy one. As just a homeowner, I will have limited future need for it. We had wired the house to code and do not think there to be a problem with the wiring.
For information, the phone antenna had been within 2 inches away from the GFCI when we had our problem and we live in a weak signal area.
Note that the problem is most likely due to the phone interacting with the GFCI internals, not causing an actual "fault current". The GFCI contains two highly sensitive transformers and associated electronics. Normally the transformers "null out" all external electromagnetic fields, but if a source of interference is close enough then it's possible to induce an apparent current in the transformer, due to the gradient (rapid change) of field strength with distance -- the field is actually stronger on one side of the transformer vs the other.In addition, the electronics that attach to the transformer are quite sensitive and similarly vulnerable to a field strength gradient.Finally, it may happen that the wavelength of certain cell phones (and wavelength varies with technology) coincides with some dimension inside the GFCI, effectively amplifying any interference that occurs.I'd guess that you'd have to have the phone within a foot or two of the GFCI for anything to happen, and the effect would increase dramatically the closer you got. Probably moving the phone even 3-4 inches farther from the GFCI would be sufficient to eliminate the problem.
In the face of overwhelming opposition, I surrender.
But I still hope he tries a GFCI receptacle tester on all the outlets on the kitchen circuits, GFCI and non-GFCI. Al, the cost is $9.50 in my Home Depot catalog, but is probably a little higher now. Also they check for many common problems on regular receptacles, too: hot-neutral reversed, etc. (And work as a very weak night-light in a pinch !)
The GFCI's already have a self test button.And while a number of self test button's don't check eveything in the case of the GFCI they do the samething that the external tester does.And in fact they will truely test the GFCI in cases where the external tester won't. Thos are where the GFCI was installed as an upgrade on an ungrounded circuit.
As I said before, I am hoping he will use the tester on both the GFCI's and the regular receptacles that are on the same circuits, as a verification that the wiring is as he thinks it is.
Most "digital" cell phones transmit and operate at 900 mHz(nearly microwave), older phones (analog) operated at 300mHz. The peak to peak at 900 mHz is about six inches, this is why (internal & external length combined) antena for the more modern cell phones is only needed to be about 3" (half the peak to peak), and why tiny phones have nearly no visible external antena. This is also why digital (900 mHz) phones are more prone to "line of sight" interruptions of signal (when a slight breeze moves the leaves on a tree between you and the cell site). This is also why those older phones needed to be larger/longer or had extendable antenae.
It is the frequency (radio signal) of the signal for the "handshake" of the phone (when the phone calls out, "Hey system, I'm here! My electronic serial number is XXXXX, I'm answering to phone number xxx-xxx-xxxx, and I'm ON" and its proximity to the GFCI recepticle, that is most likely triggering. I'm going to take on a huge guess here, that your home is NOT wired with THHN in EMT with metal outlet boxes with metal guard plates, and more likely you have romex and plastic recepticle boxes.
Now, 3 things:
1) Modern UL standards for GFCI recepticles CHANGED effective Jan 1, 2003. The standard number is the same, but one needs to check the spec sheet enclosed with the recepticle as to WHICH DATE of the standard it complies with, you can look up the listed number and cross reference on UL's site. The newer standard should help you a bit in this respect.
2) Only the end of run of a recepticle, GFCI or not can be "back-stabbed" and, personally I am NEVER a fan of such a practice. If you are on the load side running and protecting the GROUNDED outlets "down stream" you MUST use the screw terminals. Be that said, If you are individually using a duplex GFCI in each and every case, independant, used or unused, those load terminals can pick up when unsheilded this type radio frequency as well as EM generated by the operation of the phone itself, interferrance, as well as leaking microwave energy from a microwave, and also those 900mHz cordless phone base units and hand held receivers. The GFCI is (should be to meet UL standard) designed to trip at FIVE (not six) mA +/-1. If you want to know about the strength potential of the EM field generated by a cell phone, go to firstgov.gov and follow links to EPA, CPSC, FCC and FTC and if you peek at the articles that asked the ? do cell phones really cause brain cancer (answer we don't think so) it WILL give you info on that EM interferrance field.
3) tHis is why as a standard practice "old-timer" electricians always wrap the wiring/post screws with 3 wraps of (90 degrees C or higher) electrical tape before pushing the recepticle back into the box and mounting -- as old-style "ma-belle" princess phones that required in the old days a transformer to be in house to power the lighted dials/buttons used to cause similar interferrance to solid state devices plugged into the same electrical system. Old different problem, different radio frequency, same solution. Shielded systems are not as supscepticle to such interferrance, and is why some hospitals now allow cell phone use in many areas/all areas. Depends on how well their systems are shielded, and what equipment (medical equipment esp. external pacemakers) shielding they have in place. Also, those plastic recepitcle plates in themselves don't do a great job of shielding themselves, but with the tape they'll be adequate at 900mHz.
Finally, in a properly grounded electrical system you are actually REDUCING your protection using multiple GFCI down stream, as in a reverse wiring situation, the FACE OF THE ORIGINAL GFCI WILL REMAIN ENERGIZED, and in an arc fault situation when reversed, you could have a FALSE SENSE OF SECURITY. For the MINOR cost involved, I would NEVER re-use a GFCI recepticle previously installed elsewhere. Each and every trip and exposed hazard, REDUCES ITS USEFUL LIFE, and can render it INEFFECTIVE at its INTENDED PURPOSE (failure to trip in presence of hazard despite tripping using TEST button). I would STRONGLY recommend use of a modern GFCI recepticle (with visible indicator) and with LOCK-OUT protection (refusal to reset in the presence of reverse wiring). Also make sure that your GFCI's are properly rated for your wiring gauge and circuit (15A vs 20A). If you have 20 A circuits and 20 A receptcles (2002 NEC) then you must have conductors properly rated for that circuit (12 awg or if alum or copper/alum 10awg) and larger if distance etc. requires derating. If you need some reading reference links, let me know.
P.S. MAJOR (you mentioned pig-tailing): Sure hope that EACH and EVERY time you are re-wiring or re-placing those recepticles you are USING BRAND NEW WIRE NUTS. Cheap expense but you should NEVER RE-USE a wire nut EVER!!!! the smallest amount of oxidation, etc. and you will have a potential ARC fault problem or worse. NEVER EVER re-use wire-nuts, and make sure you are using GOOD ONES not those cheapo Non-listed NON-90 degree plus Celcius NOT RATED for branch circuit conductor gauge wiring that you're connecting to that come with some of those GFCI's. BUY YOUR OWN and USE THEM. THIS IS NOT AN AREA TO SKIMP on!!!! can refer you to reams of materials by NFC, CPSC, the Insurance Institute and others regarding the multitude of home fires traced back to re-used/under-rated/corroded or oxidized WIRE NUTS. (your pigtail references!!!!).
Edited 3/6/2005 12:45 pm ET by Ell
"2) Only the end of run of a recepticle, GFCI or not can be "back-stabbed" "I have never seen a GFCI that has back-stab connections.And for those receptacles that do have back-stab connections I have never seen any prohibition that only allows them to be used on the last receptacle in a run. If that was the case then why are there sets of back stab connections on them. Not that I am advocating them for ANY CONNECTION.However, the pressure plate back wire connection availavle on spec & commercial grade and GFCI's are good things." If you are on the load side running and protecting the GROUNDED outlets "down stream" you MUST use the screw terminals. "Why, if the listed device have back wiring connections?And why emphasis on GROUNDED down stream receptacles. The connection would be the same whether they where grounded or not."If you are individually using a duplex GFCI in each and every case, independant, used or unused, those load terminals can pick up when unsheilded this type radio frequency as well as EM generated by the operation of the phone itself, interferrance, as well as leaking microwave energy from a microwave, and also those 900mHz cordless phone base units and hand held receivers."It is not just those load terminals. But also the actual contact bars in the receptacle.However, a more likely place is the IC that determines the logic or it can directly fire the SCR that trips the relay."3) tHis is why as a standard practice "old-timer" electricians always wrap the wiring/post screws with 3 wraps of (90 degrees C or higher) electrical tape before pushing the recepticle back into the box and mounting -- as old-style "ma-belle" princess phones that required in the old days a transformer to be in house to power the lighted dials/buttons used to cause similar interferrance to solid state devices plugged into the same electrical system."Electrical tape will have absolutely no affect on this.The only use for electrical tape on the receptacles is if they are in a metal box it reduces the possibility of a hot terminal comming into contact with the box.
Yeah, the old Princess phones were before the days of "solid-state devices" for the most part, and the Princess transformers in any event didn't cause any interference to speak of.
Re:"Electrical tape will have absolutely no affect on this."I agree. Electrical tape has no effective insulating qualities against radio waves. Similarly the cell phone plastic body had a negligible effect. Old timers, and sometimes younger sort and as you note, wrap the receptacles to prevent shorting. Mostly it isn't necessary IMO except where tight mud rings or metallic 'goof' rings are present.
The electrical tape was to insulate fingers that might slip in there before the cover got put on.
While I agree that rf from a cellphone could possibly trip a gfi, I don't think it's probable. A cellphone transmits less than a watt. ( can't remember, but think its 700 mw. .7watt) I routinely transmit 1500 watts, although not on 900 mhz,and have never tripped a gfi.
So, you're either an illegally powered up CB'er or a Ham, and if a Ham, should know better. the peak to peak at 80mHz is much longer than 900mHz! and would have a hard time bouncing within that receptical box and being transmitted by the line conductor into the receiptical circuitry.
Then read THIS:
http://www.ul.com/seasonal/spring/gfci.html
and THIS: http://www.ul.com/consumers/groundfault.html
and THIS:
http://www.ul.com/media/newsrel/nr102903.html
then test your devices:
http://www.ul.com/tca/spring04/qa.html
then look up their listing info:
http://database.ul.com/cgi-bin/XYV/cgifind.new/LISEXT/1FRAME/srchres.html?begin=0&collection=/data3/verity_collections/lisext&vdkhome=/usr/app/verity_sw_rev24/common&query=KCXS%3CIN%3ECCN+and+not+GUIDEINFO&SORT_BY=textlines:asc,ccnshorttitle:asc
then contact your manufacturer and find out if your devices meet the January 1,2003 and after standard!
and be wary if yours are some of the estimated 400 MILLION installed in the usa that were manufactured and labeled prior to Jan 1, 2003 that are vulerable, and IF one of the estimated 50-70 million that were especially vulnerable to "environmental noise" and Radio Frequency damage.
You should also be aware that they (GFCI recepticles) like all devices are made to a standard that requires a certain time period of "useful life" wherein they are effective. that each and every over current (surge) that they are exposed to, and every TRIP that occurs, REDUCES its useful (works properly) life, it is the circuitry to detect AND RESPOND to a 4-6 mA (5 mili-amp plus or minus) differential that is effected, not its ability to sustain a monthly "activation test". Therefore it is entirely possible to have a GFCI Tester show all is a-okay, for it to preform correctly to the "test button" test, yet still NOT TRIP in the presence of a 4-6 mA differential between "hot" and "neutral", thus giving the user a false sense of security and presenting a bigger danger than if it were not there in the first place!
Edited 3/9/2005 3:35 pm ET by Ell
Edited 3/9/2005 3:37 pm ET by Ell
Edited 3/9/2005 3:42 pm ET by Ell
At the risk of being brief, I was not assuming that the rf was getting into the box from the front. The rf would be induced onto the incoming/outgoing lines to the GFI. The whole house of wire acts like an antenna to rf. And a longer wavelength would be more likely to be induced into the wireing than a very short one like the cell signal.
No Seb, that's the opposite. It IS entering from the front of the box, or side, right there at the GFCI recep. That's why moving the phone AWAY stops the problem, or in OP's case, causes the problem to occur at the next nearest recep (closest to the phone). More than likely he's got recep's manufactured before Jan 1, 2003 (although some afterwards are overly sensitive also, but wrapping the terminals/conductors with electrical tape will shield. Then as long as he keeps the phone 6-12 inches away from the actual "plug in spots" he won't have any problem), otherwise if older manufacture date, he should replace ALL those GFCI recepticles with those that meet the NEWER UL standard (post jan 1 2003 manufacture) and make SURE that they aren't some of those over 135,000 ones made between Jan and Sept 2003 that were recalled. Then, viola! no more problem! (assuming of course that his wiring and all is fine - and this entire problem isn't just a co-incidance, but that appears unlikely, since its a proven fact that RF at digital frequencies is KNOWN to cause problems with CERTAIN GFCI recepticles, that this damage is cumulative, and can render the recepticle's GFCI protection useless, even though the manual test works fine, its the components and circuitry within that detect and react to the mA changes that is damaged, not the overall response mechanism.
So to clarify, its leaving the phone, and entering the receptical at the face or side, the conductor points carry it from the innerards of the box into the GFCI circuit, it trips in response. When recepticle A trips, all those "down stream" are no longer engergized.
Since I havent had enough coffee to continue in this contest, I will leave with one final comment. Electrical tape,is in no way shape or form, a shield for rf...
"Since I havent had enough coffee to continue in this contest"I don't think that all of Starbucks can supply enough coffee.But you have to admit that it has certain "enterainment" value.
It's the field GRADIENT that is probably the problem. When you have an antenna real close to the GFCI you get a significant gradient across the torroids inside the unit. The torroids will reject a uniform field (which any antenna more than about a foot away will approximate), but not a field gradient.
first of all, yes there are GFCI recepticles that do have back stab connections in addition to the screw posts for load and neutral. The UL allows for this, but ONLY for the end of run. Code also discusses this. I think you need to do some reading on the UL standards for GFCI recepticles to further understand how they actually work, and that the newer standard does not protect if the first one is backstabbed "backwards" (neutral and hot reversed) from the face. If there is an arc fault or a ground fault, ONLY those "down stream" will be protected if reverse wired, the face of the first GFCI will still be energized, until it is tripped, and the WAY that pre-Jan 2003 standard GFCI recepticles worked did NOT provide protection (at the plus/minus 5mA) if wiring was reversed, either in the first, or those regular recepticles downstream correctly, and provided what both UL and the US CPSD considered a more dangerous situation, i.e. a false sense of security. EVEN with the NEWER standard which requires a visible indication (usually a light) VERIFYING that the first GFCI receptical IS wired correctly, it will NOT protect those additional outlets that are "down stream" that are NOT, correctly, and should CERTAIN conditions occur at ONE of those outlets, or the wiring between them, ALTHOUGH those recepticles may cease to function, the FACE of the originating GFCI (if wiring was crossed or reversed) MAY REMAIN ENERGIZED to a degree sufficient to cause HARM (to either person or property). GFCI devices are NOT ARC FAULT protectors, they are different functions, and look for paths to ground and differences between load and neutral not connections between the two.
Secondly, at 900 mHz, three wraps of standard 90 degree plus electrical tape IS a sufficient insulation to prevent absorbtion of nearly microwave frequencies by the conductors attached to the GFCI circuit. The box, if metal or plastic especially if in series with other outlets nearby (and a kitchen counter has them at least every 2 feet by code), act as capture devices for the harmonics and amplify them, and copper wire is an excellent conductor of such energy. A simple phase-lock loop and signal meter will show you what I mean. Keep in mind that minimal sheilding is necessay for example in a microwave oven to prevent microwave engery from leaking, yet they still warn those with pacemakers to avoid being within a certain distance from them while in operation as all modern microwaves have the ability to leak a certain amount of this energy and still pass inspection (and over time they may leak more). Check out the gasketing for any door, and or its overlap pattern and you'll see what I mean. Drywall and taping/mud compounds do not devert this energy well (ya use paper products and glass and plastic in the microwave all the time), yet metal absorbs it. Think about what happens when you put aluminum foil in the microwave, enjoy the arcs. Now remember that coper is an even better conductor and receiver of such energy. The best easiest way to make a receiver antena is to simply string copper wire with a few crystals or a coil or two, to focus which frequency you want to focus on -- however it also attracts every other kind of energy, this is why we don't do this by itself often in radio commnications. I really don't want to get into a physics discussion with you, but you will find that this is one of the suggested solutions by the FCC when you are having problems with such interferance. You cannot adjust a GFCI circuit with capacitors. What I was referring to regards to the old system of the transformer energized by house current being put on the house telephone line to power those old princess phones was the situation I was referring to IN REVERSE where such devices caused radio interference through the household conductors, and made even transistor radio reception difficult. Sheesh you're adding 2 plus five and getting three. GFCI's do NOT protect against abnormal conditions such as normal load current levels but that do not involve arcing or current to ground (e.g. high resistance series faults, usage of undersized conductors, etc.).
We were discussing the situation where the level (between one-third and seven-tenths of a watt) of powered focused nearly microwave level frequency (900mHz) can interfer with the circuitry of an ordinary GFCI receptical and cause it to trip when no ARC fault or ground fault is occuring. Yes, the triple wrap of the terminal screws WILL insulate those conductors. Then you have the ONE remaining source e.g. entrance through the unused terminal ports in the recepticle itself. There you assure that the direction of the antena is always running (pointing) at right angles to the outlet. By the way the handshake frequency is not the same as the sending nor receiving frequencies. A CELL PHONE IS A RADIO, nothing more, nothing less. As I said in my first post, this is why modern digital cell phones are so sensitive to changes in the line of site to the cell tower, i.e. when a leafy tree is having its leaves blown by the wind. Its not the action of the wind on the radio waves (none) its the action of the wind blowing the leaves that more leaves are in your signal path. Those radio signals bounce (deflect) on things at that frequency easier than they penetrate, yet require LESS energy (watts) to travel further unabstructed. Example: AM radio, you can pick up skip on a clear summer's night sitting in NYC and listen to a LA station in Hollywood, AM radio brodcast tower has to be a tremendous level of WATTS to brodcast any significant distance clearly, go under a bridge next to the tower, and the signal is interupted. Its a much longer peak to peak, requires more power to generate it, is less likely to bounce and direct WITHIN your intended broadcast area) FM radio (higher radio frequency) requires fewer brodcast watts to penetrate the same area, is less interferred with driving under that bridge, but requires a bit more antena coil to receive it, its peak to peak is closer together, and when bounced therefore more likely to remain within its intended area before losing power. Also more easily focused and doesn't interfer at those levels of power broadcast at other frequencies, this is why locally you can have more stations closer together on the "FM DIAL" broadcasting without "stepping on" the other nearby (on the "dial") broadcast stations, where as in AM there must be more "space on the dial" between local broadcast "domes" and if you have the unfortunate situation where you live NEXT TO such a HIGH wattage AM station, you might experience radio interferrance to a greater degree in ALL frequencies (huge leakage). The shorter the peak-to-peak the more sharply the deflection angle/arc can be, and the less dense the material needed to deflect (shield) a penetration. There is a lot more involved in that entire senerio, but I'm trying to k.i.s.s. here and be more direct to the point of where and how one can get those signals bouncing and introduced into the GFCI circuitry and cause an in-advertant TRIP. The path to the circuit is almost always the unshielded conductor ends. There are three major differnces in how a GFCI device works, we're addressing the most common found in household GFCI recepticles.
UL produced a warning in early 2004 regarding sensitivities to certain GFCI devices to both over current AND RADIO FREQUENCY INTERFERRANCE, you can read one of several such warnings at http://www.ul.com/seasonal/spring/gfci.html . You'll find some easy to understand information about the NEW standards info on NEWER GFCI recepticles (less subsceptable to "noise" - radio frequencies included -) at: http://www.ul.com/consumers/groundfault.html . More than 135 thousand GFCI recepticals produced from Jan 2003 (supposed to be new standard) and August 2003 (both 15 A and 20 A) were found to be defective and don't work, even though they "test" okay and were recalled. Read about this at http://www.ul.com/media/newsrel/nr102903.html remember that the products were believed to be sold under other names than those listed as well.
How UL maintains a PROPER and FULL test of a GFCI circuit can be found in this informative Q&A (Its the 3rd or fourth Answer) at http://www.ul.com/tca/summer04.qa.html
You can learn about just what GFCI's are supposed to do and what they don't by reviewing UL standard 943 (498) at: http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=KCXS.GuideInfo&ccnshorttitle=Ground-fault+Circuit+Interrupters&objid=1074098655&cfgid=1073741824&version=versionless&parent_id=1073988928&sequence=1
and KCXS.GuideInfo (Ground-fault Circuit Interrupters) at:
http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=AALZ.GuideInfo&ccnshorttitle=Electrical+Equipment+for+Use+in+Ordinary+Locations&objid=1074077254&cfgid=1073741824&version=versionless&parent_id=1073983908&sequence=1
and
RTRT.GuideInfo (Receptacles for Plugs and Attachment Plugs) at:
http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=RTRT.GuideInfo&ccnshorttitle=Receptacles+for+Plugs+and+Attachment+Plugs&objid=1074120002&cfgid=1073741824&version=versionless&parent_id=1073992975&sequence=1
you can check the listing of your GFCI recepticle at: http://database.ul.com/cgi-bin/XYV/cgifind.new/LISEXT/1FRAME/srchres.html?begin=0&collection=/data3/verity_collections/lisext&vdkhome=/usr/app/verity_sw_rev24/common&query=KCXS%3CIN%3ECCN+and+not+GUIDEINFO&SORT_BY=textlines:asc,ccnshorttitle:asc
If you want to know what is covered by UL943, you can review its "scope" at:
http://ulstandardsinfonet.ul.com/scopes/0943.html
And know that changes were issued regarding the addition of requirements to add a GFCI "end of life cycle" test and revisions of requirements for reverse line-load miswire test and that proposed changes are being considered to revise requirements for grounding and bonding connections.
Other good References: UL Study for the CPSC (consumer product safety commission) CPSC-C-94-112; NFPA (authors of the NEC) 70 May 2001 ROP Logs May 2004 ROP Logs (Las Vegas, NV - NFPA (authors of the NEC), 2005 ed of 2002 NEC, also sec 200.6(C), (D), 250-8, 250.122(E), 250.126 and figure 250.126, 250.146(B), 250.147 (new) Grounding of General....As a footnote 250.147 has been removed from 2005 NEC and deferred to the text appearing in 404.9(B) for grounding of switches, 250.118(5), (6), and (7)e, Types of equipment grounding conductors, flexible metal conduit, where (1) flexible metal condit is NO LONGER acceptable as an equipment grounding conductor without the restrictions stated in 250.118(6) and (2) where flexibility of flexible metal conduit or liquidtight flexible metal conduit is necessary after installation, an equipment grounding conductor in the form of a wire shall be installed., and 210.8(B)4 and 210.8(C).
I've forgotten now whatelse you said, I'll have to re-read your post and add another if I forgot anything. Oh yeah, never seeing GFCI recepticles that can be back (end) stabbed, Leviton making them for years. Restriction on backstabbing ? both UL and NEC if any OUTLET (meaning recepticle OR luminare OR switch) follows it in a circuit. Uh, simple answer why? cuz only the screw terminals are meant to carry conduct THRU(beyond) backstab not. also NEW 2005 NEC does NOT allow ya to stab the grounding wire in the box anymore either GOTTA use the proper screw connection of the ground wire to the box (if that's how its being grounded.) and your theory on the contact bars, NOPE its the exposed COPPER or if so rated and in the circuit alum or copper wrapped alum wire thats wrapped under those screw heads that's causing the problem, NOT the contact bar, NOT the load terminal screws themselves either. its the conductor wire. Should I have mentioned that the actual engineers that perform this very testing for UL are freinds of mine? That I dealt with this issue for a major B company and 2 manufacturers as this transition to "digital" was first taking place? That a similar problem can occur in certain situations with certain cordless telephones as well? LOL!!! This is a known problem for a long time, AND ESPECIALLY prevelent regards to CERTAIN OLDER GFCI recepticles and even NEWER ones that are excessively exposed to overcurrent situations (NOT ground faults). Do some reading and understand more than just basic wiring before you start telling me what electrical tape will and will not insulate/shield. I sure hope my references are right on the 2005 edition, as I won't have a hard copy till after the first, and I'm a bit overtired at the moment. Hope I addressed ALL your questions.
Edited 3/9/2005 3:08 pm ET by Ell
"first of all, yes there are GFCI recepticles that do have back stab connections in addition to the screw posts for load and neutral. "There might have been some in the year past just like I have run across backstab receptacles that take #12 and GFCI with wire leads.But are there any currently made devices like that."The UL allows for this, but ONLY for the end of run.:In all of those links that you posted. did I find anything like that. What I did find was a link in the GFCI section that indicated that it also followed the requirements for receptacles. and in that one. http://tinyurl.com/64wxy"Screwless terminal connectors of the conductor push-in type (also known as "push-in-terminals") are restricted to 15 A branch circuits and are for connection with 14 AWG solid copper wire only. They are not intended for use with aluminum or copper-clad aluminum wire, 14 AWG stranded copper wire, or 12 AWG solid or stranded copper wire.Single and duplex receptacles rated 15 and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors have been investigated to feed branch circuit conductors connected to other outlets on a multi-outlet branch circuit, as follows: * Back wire (screw actuated clamp type) terminations with multiple wire access holes used concurrently to terminate more than one conductor
* Side wire (binding screw) terminals used concurrently with their respective push-in (screwless) terminations to terminate more than one conductorSingle and duplex receptacles rated 15 and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors have not been investigated to feed branch circuit conductors connected to other outlets on a multi-outlet branch circuit, as follows: * Side wire (binding screw) terminal with its associated back wire (screw actuated clamp type) terminal
* Multiple conductors under a single binding screw
* Multiple conductors in a single back wire hole
"And that specifically allows the use of the backstab (push-in) terminals to be used for feed through applications." I think you need to do some reading on the UL standards for GFCI recepticles to further understand how they actually work, and that the newer standard does not protect if the first one is backstabbed "backwards" (neutral and hot reversed) from the face."Actually the GFCI, new or old, will work if the line and hot are reversed. Whether the connections where made via the screw terminals or the back wire (or back stab if there was one).Have you looked at the schematic of the GFCI circuit? There is no way for it to work differently if the hot and neutral where reversed.I think that what you are talking about is a completely different sistuation, where the LINE and LOAD connections are reversed. BUT THE PROBLEM IS EXACLTY THE SAME WHETHER CONNECTIONS ARE MADE BY THE SIDE TERMINALS OR BACK WIRED OR BACK STABED."GFCI devices are NOT ARC FAULT protectors, they are different functions, and look for paths to ground and differences between load and neutral not connections between the two."Agreed, but again what does that have to do with the discussion. You keep throwing in random stuff that has nothing to do with the discussion." If there is an arc fault or a ground fault, ONLY those "down stream" will be protected..." But it would not be protected from a arch fault EVEN IF WIRED CORRECTLY. As you said the GFCI is an an arc detector."Secondly, at 900 mHz, three wraps of standard 90 degree plus electrical tape IS a sufficient insulation to prevent absorbtion of nearly microwave frequencies by the conductors attached to the GFCI circuit."Now I checked in the following;"Microwave Principles" by Reich, Skalnik, Ordung, Krouse
"Electromagnetic" by Kraus
"Applied Electronics" by Gray
"Therory of AC circuits" by Fich and Pottor
"Electronic Engineering" by Alley & Attwood
"Baisc Electronic Engineering" by Fitzgerald, Higginbotham, Gravel
"Semiconductor Electronics" by Gibbons
"The Electronics Handbood" IEEE Press.
"ARRL Handbook"Did not find a single sentence that backed up your comment on the ability to "insulate" against RF energy."The box, if metal or plastic especially if in series with other outlets nearby (and a kitchen counter has them at least every 2 feet by code), act as capture devices for the harmonics and amplify them,"Nor could I any thing that would cause platic boxes, whether single or one many, to either "capture" or amplify the signal, neither the fundemental or the harmonics.Have you tried running a Fourier series on those harmonics?And if either the plastic box or metal box AMPLIFIED the singal then that would violate the all of the know laws of physics."Drywall and taping/mud compounds do not devert this energy well (ya use paper products and glass and plastic in the microwave all the time), yet metal absorbs it. "So are you saying that you are rapping those terminals with metalic tape? Interesting. Let me know the next time that you are doing this. I might just pay to watch."I really don't want to get into a physics discussion with you, but you will find that this is one of the suggested solutions by the FCC when you are having problems with such interferance. "Can you show me where the FCC recommends that tape be used other than as an insulator.Bill, BEEE, MSEE
Edited 3/9/2005 4:20 pm ET by Bill Hartmann
Bill: You state:
"Single and duplex receptacles rated 15 and 20 A that are provided with more than one set of terminals for the connection of line and neutral conductors HAVE NOT BEEN INVESTIGATED TO FEED BRANCH CIRCUIT CONDUCTORS CONNECTED TO OTHER OUTLETS ON A MULTI-OUTLET BRANCH CIRCUIT, as follows:
* Side wire (binding screw) terminal with its associated back wire (screw actuated clamp type) terminal* Multiple conductors under a single binding screw* Multiple conductors in a single back wire hole" (CAPS MINE),
Then you opine: "And that specifically allows the use of the backstab (push-in) terminals to be used for feed through applications.", which is WRONG and the OPPOSITE of what is ALLOWED. To do so would VOID the UL approved/listed USE, and subject the property owner to ZERO INSURANCE COVERAGE, and now they'll be suing YOU. your own quotation just above specifically allowed only:
"* Back wire (screw actuated clamp type) terminations with multiple wire access holes used concurrently to terminate more than one conductor* Side wire (binding screw) terminals used concurrently with their respective push-in (screwless) terminations to terminate more than one conductor" That's referring to the back stabbed to box and wire nuts NOT backstabbing the recepticle itself. Obviously you are having difficulty digesting what you're reading. Through connections must be SCREWED, period, end of story. You can't put multiple conductors under a single binding screw, you have to wire-nut them and pig-tail it (single) to the screw, done. we are so NOT going to hash this out forever, you're wrong. Your citation is right, your conclusion/interpretation is wrong.
The scematics of a GFCI circuit, Yep, SURE HAVE. maybe you need to LEARN how those COMPONENTS work, because if you don't understand how reverse wiring can leave the FACE of the recepticle LIVE, then you're NUTS.
and that you actually think that old un-grounded 2-wire homes single GFCI repticle protects anything down the line, unbelievable. throw all the degrees ya want after your name Bill, you obviously got a raw deal, as you are missing something serious in your understanding of the circuitry.
#12 AWG Copper (#10 alum or copper wrapped alum ONLY for those GFCI recepticles marked compatible for that purpose) is GENERALLY used for 20 amp circuits, OR those that due to distance/load drop require a BOOST for 15 amp circuits. #14 AWG copper is commonly used for 15 amp circuits in household wiring, esp older homes. So you contradicted yourself regards to "what you have seen" floating around the market place, and NOW they (backstab-ability) should ONLY be found on 15Amp GFCI's your own citation states. So you're contradicting yourself again.
I REPEATEDLY REFERED YOU TO UL's OWN GENERAL release regards to the concluded FIELD INVESTIGATIONS that PROVED that CERTAIN GFCI's ARE VULNERABLE TO RF interferrance.
A reverse wired GFCI recepticle MAY trip appropriately when a +/- mA is prior or FROM the circuitry, but MAY NOT trip if such a fault is present beyond it.
A correctly wired GFCI contained in a branch circuit with underrated conductors WILL NOT PROTECT correctly, please read the CPSC report on that I referenced it you will learn something. you ARE aware that the lower the # of the AWG the higher amperage it can safely conduct, yes?
"Can you show me where the FCC recommends that tape be used other than as an insulator." you challenged. Why should I, that's EXACTLY what it is supposed to DO, INSULATE the conductors from the RF 900mHz energy.
The spread of the radio signal as it bounces, oh sheesh, I am so done, you are totally CLUELESS. I give up on YOU.
The problem OP had: RF interferance to GFCI recepticles causing inadvertant tripping. The cause: Cell phone + old style (pre Jan 1, 2003 standard) GFCI recepticles. You: disputed the facts, challenge the FCC, the CPSC, and United Labortories, AND the NFPA and the 2005 ed of the 2002 NEC, you seem to think everybody is wrong! LMAO. Me: showed ya the WHYs as to WHY UL changed the standard, WHY NFPA changed the NEC and WHY and HOW GFCI recepticles work (there are three main differences in the how and type of circuitry). You: are an idiot, cannot read simple english, and mis-interpret even what you quote, You disputed and challenged all those that explained the WHYS and HOWS a CELL PHONE could interfere with the inner circuitry of a GFCI recepticle, you refused to READ the references that anyone with a 5th grade comprehension of english could understand and digest. Me: Gives up on you as a total ignoramous and lost cause. Enuf! any more waste of time with you would only continue Ad infinitim and I refuse to waste my time. Obviously ya forgot half of what yr techie degree teachers tried to "learn ya".
"Bill: You state: "No I copy and pasted it from the UL website.But I see that you only included part of it.The section that quoted is for cases where MULTIPLE connections by trying to use BOTH the screw terminal and the BACKWIRE PRESSURE PLATE (along with disallowing multiple wires on a single terminal or multiple wires in a single back wire hole).The other section, which you passed over, specifically allows back wire, backstab and screw terminals to be used for feed through.And I note that the section that you did include MAKE NOT MENTION WHATSOVER OF BACK STAB (PUSH IN) CONNECTIONS. So how can it prohibit them it if does not even mention them."To do so would VOID the UL approved/listed USE, and subject the property owner to ZERO INSURANCE COVERAGE,"You are not the first on to make such wild claims. I have read policies, ask the people that have made such claims, and asked in forum. NO ONE has ever found a policy that has such a clause. In fact I have had responses from claims agent indicating such." because if you don't understand how reverse wiring can leave the FACE of the recepticle LIVE, then you're NUTS."I have made such a claimed.I will REPEAT IT AGAIN.Yes, reversing the connection between the LINE AND LOAD SIDE will cause problems. And that is what changed have been in in the UL listing to take care.THAT IS NOT WHAT YOU CLAIMED.You need to read what YOU WROTE. And then what I WROTE.You said that reversing the NOT AND NEUTRAL would cuae the problem. Apparently you don't understand the difference between load/line and hot/neutral.""Can you show me where the FCC recommends that tape be used other than as an insulator." you challenged. Why should I, that's EXACTLY what it is supposed to DO, INSULATE the conductors from the RF 900mHz energy."Boy I have not laughed so hard for years.Let me suggest a little experient.You cover inside walls of your microwave with tape. Then put an egg in it and set the microwave for high for 10 minutes.According to what you claim the egg will not be affected.
oh yeah, and Bill, you asked WHY the reference on GROUNDED GFCI recepticles. LOL, because they are ALSO used BY THEMSELVES to protect ONLY the actual recepticle itself as replacement for old 2 wire NON grounded systems in older homes, and in that SPECIAL and LIMITED purpose are supposed to be labeled no service ground, when installed for THAT LIMITED purpose there is an ENTIRELY of SPECIAL INSTALLATION ISSUES and RULES and DO's and DON'Ts and what in-place what those single duplex GFCI recepticles can and CANNOT do. Both in the listing (UL) design (manufacturer) and the NEC, lordy, you really didn't see where I was going there?
"oh yeah, and Bill, you asked WHY the reference on GROUNDED GFCI recepticles. LOL, because they are ALSO used BY THEMSELVES to protect ONLY the actual recepticle itself as replacement for old 2 wire NON grounded systems in older homes, and in that SPECIAL and LIMITED purpose are supposed to be labeled no service ground, when installed for THAT LIMITED purpose there is an ENTIRELY of SPECIAL INSTALLATION ISSUES and RULES and DO's and DON'Ts and what in-place what those single duplex GFCI recepticles can and CANNOT do. Both in the listing (UL) design (manufacturer) and the NEC".All true except that the GFCI is not limited to protecting themselves, but also ungrounded downstream recetpacles."you really didn't see where I was going there?"And I still don't.What does the any of these have to do with the SUBJECT. RFI sensitivity of GFCI's or the effects of tape on RFI.I can throw in a discussion on automatic backup in radio controls systems, but it would be just as measingless to this discussion.
Bill!
You OBVIOUSLy didn't read any of the links or references I gave, so I'll quote:
"Field research recently conducted by Underwriters Laboratories Inc. found that ELECTRONIC COMPONENTS in a small percentage of ground fault circuit interrupters (GFCIs) - especially older ones - CAN BE DAMAGED OVER TIME BY power surges AND RADIO SIGNALS, THEREBY REDUCING THEIR CAPACITY TO PREVENT FIRE, ACCIDENTAL SHOCK AND ELECTROCUTION." (emphasis mine)
"Last year, UL issued new safety requirements for the devices. GFCIs manufactured after Jan 1, 2003, must comply with the new requirements in order to bear the UL Mark....."
"'More than 400 million GFCIs were installed throughout the United States before the new requirements took effect,' he says, 'and the possibility remains that some of them will eventually fail to work correctly.'" (quoting John Drengenberg, UL's Consumer Affairs manager).
"December 20, 2003: Underwriters Laboratories periodically revises requirements in its Standards for Safety to harmonize with international requirements, address code and safety issues, and accommodate new product developments as applicable. UL has adopted new and revised requirements for Ground-Fault Circuit-Interrupters (GFCIs) that become effective January 1, 2003. Among others, these requirements include enhanced requirements for immunity to voltage surges, resistance to moisture and corrosion, reverse line-load miswiring, and RESISTANCE TO ENVIRONMENTAL NOISE. Though products meeting these revised requirements will soon enter the marketplace, they are not required to have any special markings to distinguish them from models made prior to January 1, 2003. Models of GFCIs Listed by UL that were manufactured and labeled prior to January 1, 2003 still may appear in the marketplace after January 1, 2003, and until such time as old stocks of GFCIs become exhausted." (Caps/emphasis mine).
The other link was pertaining to thousands (over 135,000 of them) of GFCI's produced from Jan thru Sept 2003 that did not only NOT meet the current (post Jan 1, 2003) standard, but frankly didn't work at all to stop +/- 5mA differences, yet when tested with the "test button" technique with a lamp, functioned fine, the circuitry for detection was defective.
my point regards to individual use of individual GFCI duplex recepticles with NO GROUND was that there is NO exception in those cases they must ALWAYS be terminal screw wired, never back-stabbed, even when end of run.
You realize of course that the NEC limitations and UL limitations regards to back stabbiing provide that one can ONLy back stab when it is the terminating/final OUTLET on the branch circuit. Outlet means any break before return to the main, not just recepticle, could be a luminare, a switch, a fan, anything. If anything follows it has to be connected using terminal screw connection., but in a 2-wire non-grounded situation using the GFCI for single location it can NEVER be back-stabbed.
Now your "all true except that it also protects all downstream recepticles" in a 2-wire NON-GROUNDED situation?!? NO IT DOESN'T, IT CANNOT, EVER not without a ground, and then we're moot again. Bill!!!!! if the old style non-grounded outlet HAS NO GROUND, that GFCI is offering NOOOOO DOWNSTREAM PROTECTION WHATSOEVER!!! THERE IS NO GROUND. It provides NO PROTECTION NO SENSE NO CIRCUIT TO GROUND FOR THE UPSTREAM GFCI TO DETECT. YOU ARE DANGERIOUSLY MISTAKEN!!!!
The subject was high frequency RFI's effects to certain GFCI receptical circuitry, its signal path, and ways to protect/correct it. IF the recepticals are of a certain type, nothing will help. If it is a situation of one GFCI GOOD NEW STYLE, and regular recepticles downstream, WRAPPING THE TERMINALS WILL PREVENT the interferrance. Plain and simple. Read bill, consult those who know something about ELECTRONICS and radio frequency interferrance. LEARN. otherwise stop shooting off because you are WRONG. I have links to the UL site on my previous post you could have easily perused, in LAYMAN TERMS to substantiate what I told you. Furthermore I referred you to FCC, CPSC, NEC, NFPA, and other references and sources. I can do nothing more if you refuse to even TRY to understand the cause/effect/solution.
Edited 3/9/2005 4:28 pm ET by Ell
"Now your "all true except that it also protects all downstream recepticles" in a 2-wire NON-GROUNDED situation?!? NO IT DOESN'T, IT CANNOT, EVER not without a ground, and then we're moot again. Bill!!!!! if the old style non-grounded outlet HAS NO GROUND, that GFCI is offering NOOOOO DOWNSTREAM PROTECTION WHATSOEVER!!! THERE IS NO GROUND. It provides NO PROTECTION NO SENSE NO CIRCUIT TO GROUND FOR THE UPSTREAM GFCI TO DETECT. YOU ARE DANGERIOUSLY MISTAKEN!!!!"The GFCI has a torrid transformer through which both the hot and neutral lead is wound throught in such a manor electromagnetic fields cancel.And there is a 3rd sense winding. If there is an unbalance in the currents between the not and neutral a signal is generated on the sense winding and that is used to trip the protection relay.NO GROUND WHAT SO EVERY IS NEEDED FOR THE GFCI TO WORK.You might want to look at these simplified schematics.http://www.codecheck.com/gfci_principal.htmAnd here is what the NEC (99) says;;
210-7(d)(3)(c)"A nongrounding-type of receptacles(s) shalla bve permitted to be rpelaced with a gorunding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding type of receptacles supplied through the ground-fault circuit interrupter shall be marked "GFCI Protected" and "No Equipment Ground". An equipment grounding conductor SHALL NOT BE CONNECTED BETWEEN THE GROUND-TYPE OF RECEPTACLES." (emaphasis added).
ARRRRGHHHHh Bill! DUH keep reading even your outdated 99 NEC but get thee to a library and check out 2002 NEC, or better yet order yourself up-to-date 2005 edition of the 2002 NEC. THE RECEPTICAL ITSELF with NO ground IS protected, what is PLUGGED INTO IT IS PROTECTED. What is connected via conductors beyond it IS NOT, in a home where the main power box IS NOT GROUNDED. Oh gawd the answers are right in front of you, you quote them, yet you DO NOT COMPREHEND. If you've got an OLD kitchen with OLD wiring, THATs WHY EVERY recepticle on the counter has to be a GFCI recepticle, but if you have slightly more modern wiring and your house has ground, and your recpticles ARE GROUNDED, then you can have ONE GFCI recepticle protect those and ALL OUTLETS "downstream". Although that SECOND (code required) countertop circuit needs its OWN GFCI protection.
DUH if you have neutral and hot REVERSED on a succedding recepticle from the inital GFCI recep....and then PLUG ANYTHING IN IT that has a MODERN PLUG (wide 2-fin OR a "three-pronger") YOU ARE CREATING A CONNECTION BETWEEN Hot and Neutral (ARC FAULT). by the way you are such a selective reader, did you completely miss the reference "Field research recently conducted by Underwriters laboratories Inc. found that ELECTRONIC COMPONENTS in a small percentage (400 million) of ground fault circuit interrupters (GFCIs) - especially older ones can be damaged overtime by power surges AND RADIO SIGNALS, thereby reducing their capacity to prevent fire, accidential shock and electrocution."?
a winding by its very definition is directional.
a GFCI protects against shock an AFCI protects against arc faults. apples and oranges. If you have neutral making connection to hot anywhere in the branch circuit you will DEFEAT the GFCI. GFCIs are differential current devices and need to have a complete path for differential current when a fault occurs. Or to react and de-energize a circuit within a specific period of time whenever a current-to-ground exceeds 5mA+/- 1mA. So, in an ungrounded supply system, that GFCI recepticle can REACT AND RESPOND to such conditions within the Circuit and items supplied by it (pluged in) and de-energize the circuit of the GFCI recepticle ITSELF but not react to a ground fault elsewhere in the BRANCH circuit, nor any outlet beyond it, albeit that power to those outlets would be effected should the GFCI trip, but a ground fault beyond the items plugged into the GFCI recepticle itself or the GFCI internal circuitry, would NOT be detected, and not cause the GFCI to "trip" neither within spec nor standard.
"A.5.1 Ground-Fault Circuit Interrupters. Additional protection can be accomplished by providing ground-fault circuit interrupter protection in accordance with 210.8(A) and 406.3(D)(2) of NFPA 70, 2002 edition." (hint, NFPA 70 IS NEC).
420-3(d) Replacements. Replacements of receptacles shall comply with (1), (2), and (3) as applicable.
(1) Where a grounding means exists in the receptacle enclosure or a grounding conductor is installed in accordance with Section 250-130(c), grounding-type receptacles shall be used and shall be connected TO THE GROUNDING CONDUCTOR in accordance with Sections 420-3(c) or 250-130(c).
(2) Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so prtected elsewhere in this Code.
(3) Where a grounding means does NOT EXIST in the receptacle enclosure, the installation shall comply with (a), (b), or (c).
(a) A non-grounding-type receptacle(s) shall be permitted to be replaced with another non-grounding-type receptacle(s).
(b) A non-grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). THESE RECEPTACLES SHALL BE MARKED "NO EQUIPMENT GROUND." An equipment grounding conductor shall not be connected from the ground-fault circuit interrupter-type receptacle to ANY OUTLET supplied from the ground-fault circuit interrupter receptacle.
(c) A non-grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through A GROUND-FAULT-CIRCUIT interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked "GFCI PROTECTED" AND "NO EQUIPMENT GROUND". An equipment grounding conductor shall NOT be connected between the grounding-type receptacles.
Here at least, and the councils that debate these code changes have interperated this to mean, that you got a branch circuit with non-grounded conductor and non-grounded outlets. You want to upgrade. You either: install GFCI recepticles in each and every recepticle outlet marked NO EQUIPMENT GROUND, or you install a GFCI circuit breaker at the pannel, and install grounded type recepticles (regular) and mark them GFCI protected and NO EQUIPMENT GROUND. Not a combination of ONE GFCI recepticle followed by regular grounded-type outlets. Where do you see THAT a GFCI type RECEPTICLE can replace a circuit GFCI above? NEC is pretty specific and they've discussed making clarification and editorial changes regarding above many times since 1999. Exceptions are an isolated ground face plate 250-146(d) for the reduction of electrical "noise", The BOCs always read the same. Okay, your turn!
http://www.nfpa.org/assets/files/pdf/Annex%20A%20Pt%201.pdf?src=necdigest
Pg 3, CMP 2, proposal 2-146 makes interesting reading.
The code section you cite specifies using a GFCI to protect a circuit without a grounding conductor and allows you to install grounded receptacles on the load side of the GFCI as long as you do not connect the grounding conductor and as long as you label the receptacle "GFCI Protected" and "No Equipment Ground". It does not specify that only a GFCI breaker can be used. In fact, section (b) specifically mentions the use of a gfci RECEPTACLE and how to connect receptacles fed FROM the GFCI.
BTW, you misspelled recepAcle.
I don't spell check and didn't proof it -- aww shame on me.
you have 3 choices: replace old style for old style, replace circuit breaker with GFCI breaker then use grounded type recepticles (labeled no equipment ground) in the circuit, OR replace one with GFCI style labeled "no equipment ground".
Now, if you just want a grounded type in one location and GFCI protection at one outlet, you swap just that one. you leave the rest OLD STYLE. if you want the entire circuit GFCI you either, insert GFCI breaker, and then replace all the recepticles with the grounded type and label them no equipment ground, OR you replace each and every recepticle with the GFCI type, and so label them no equipment ground.
Where do you find an exception that you can install ONE GFCI type recepticle and then replace the remaining with grounded type regular recepticles when replacing non-grounded outlets on non-grounded system? It isn't there. A GFCI circuit breaker and a GFCI recepticle in a system without grounded conductors are not interchangable, also please recall that there are 2 other code section cites oh and now current you have to refer to .12-.14 as they re-numbered them. As said before I'll get those links and post em for ya'll, then we can put this to bed.
"ARRRRGHHHHh Bill! DUH keep reading even your outdated 99 NEC "Actually it is not outdated.As you should know the NEC means NOTHING. The only thing that has any mean is what AHJ adopts. And in my case it is actually the 96 code.But that realy doesn't matter here."(c) A non-grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through A GROUND-FAULT-CIRCUIT interrupter. "WHEN SUPPLIED (that means downs stream from) a GROUND FAULT CIRCUIT INTERRUPTER.Article 100 "Ground Fault Circuit Interrupter-
A DEVICE inteded for the protection of personnel that funcitons to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds some predermined value that is less than that required to operated the ovcercurrnet protective device of the supply circuit."A DEVICEIt does not mention anything about it being a breaker type or receoptacle type or even a dead face type.The receptacles just have to be protected by a GROUND FAULT CIRCUIT INTERRUPTER DEVICE.And a GFCI RECEPTACLE, A GFCI DEAD FACE & A GFCI BREAKER ALL met that requirement."a GFCI protects against shock an AFCI protects against arc faults. apples and oranges. If you have neutral making connection to hot anywhere in the branch circuit you will DEFEAT the GFCI. "Yes apples and organges. THEY WHY DO YOU KEEP THROWING IN AFCI'S. THAT ABSOLUTLE NO PLACE IN THIS DISCUSSION. YOU KEEP MUDDING THE WATERS BY KEEP BRINGING IN STUFF THAT HAS NOTHING TO DO WITH THE DISCUSSION."DUH if you have neutral and hot REVERSED on a succedding recepticle from the inital GFCI recep....and then PLUG ANYTHING IN IT that has a MODERN PLUG (wide 2-fin OR a "three-pronger") YOU ARE CREATING A CONNECTION BETWEEN Hot and Neutral (ARC FAULT). by the way you are such a selective reader, did you completely miss the reference "Field research recently conducted by Underwriters laboratories Inc. found that ELECTRONIC COMPONENTS in a small percentage (400 million) of ground fault circuit interrupters (GFCIs) - especially older ones can be damaged overtime by power surges AND RADIO SIGNALS, thereby reducing their capacity to prevent fire, accidential shock and electrocution."?"AGAIN IN THE MIDDLE OF THE PARAGRAPH YOU CHANGE SUBJECTS."DUH if you have neutral and hot REVERSED on a succedding recepticle from the inital GFCI recep....and then PLUG ANYTHING IN IT that has a MODERN PLUG (wide 2-fin OR a "three-pronger") YOU ARE CREATING A CONNECTION BETWEEN Hot and Neutral (ARC FAULT)."My example was with the input to the GFCI reversed, not the output. But you are still wrong.I was going to try and draw it, but since I use CAD very little I am too slow on it. So I will do it verbally.Hot line connects to hot on GFCI, Hot load side connects to neutral on down stream receptacle.Neutral connects to line neutral on GFCI, neutraol load side connects to Hot on down stream receptacle.No shorts, no fires, no GFCI trips.Lamps is plugged into downstream receptacle. Hot side of plug is connected to center terminal of socket, but it connected to the neutral supply in the crossed receptacle.Neutral side of plug is connected to the lamp socket shell and the Hot supply in the crossed receptacle.No shorts, no fire, no GFCI trip.The light is turned on.Starting at the panel nominal current (for whatever size light bulb is used) flows through the hot to the hot side of the GFCI and then out the load side hot, then to the miswired neutral on downstream receptacle, then to the neutral on the plug to the shell of the socket, through the bulb. Back through the center on the socket and hot side of the plug. Then through the miss wired receptacle to netural wire. Then through the load side neutral of the GFCI and then the line side neutral back to the panel.EXACTLY the same amount of current is flowing back out the line side of the GFCI and in the hot side. Current balance. No fires, not overloads, no GFCI trips.Now someone touches the shell on the socket. Being miswired that shell is hot. They also touch something that is grounded.Then a small amount of current will flow from the panel hot to the line side of the GFCI, out the hot load side, trhough the neutral terminal on the miswired downstream receptacle and through the neutral on the plug and through the shell and throug the person to ground. It doesn to return though the GFCI and thus the GFCI detect an unbalance and trips.EXACLTY THE WAY IT IS SUPPOSE TO.
Ell, you appear to have more time than you have brains. Please take your tirades somewhere else.
Don't spoil my enterainment.I have not laughed so hard for a long time.Just wish that he would not run on so. Takes too much time to go throuhgh all of it.
You have more patience than I do.I thought I went long.After the first ten pages of links, none of which had anything new to say on the issues at hand, I glazed over.
Yes, I let myself get sucked into it.But at the sametime it is so enertaining watching him even quote the exact words and then saying that they don't mean what they say.
Edited 3/10/2005 11:58 pm ET by Bill Hartmann
Laid off the coffee today...However found a great old john where the urinals go clear to the floor...easy to keep score...you guys want the address???
How is that electrical tape RF shielding business going?I've done some work on cell sites and I think your new technique will have a lot of call providing RF shielding for their buildings. They have been messing with those Faraday cages. Lots of copper and connections. Pretty expensive too. Good thing that guy turned you on to this new and improved method. Sure it will save a lot of time and trouble. You suppose that if electrical tape works that bituminous ice shield would work also. It would certainly speed up on the big areas. But hey, if your paying by the hour, I'm into wrapping buildings with 3/4" electrical tape.
May regret extending this thread, but here goes:
Ell, you wrote:
"Now your "all true except that it also protects all downstream recepticles" in a 2-wire NON-GROUNDED situation?!? NO IT DOESN'T, IT CANNOT, EVER not without a ground, and then we're moot again. Bill!!!!! if the old style non-grounded outlet HAS NO GROUND, that GFCI is offering NOOOOO DOWNSTREAM PROTECTION WHATSOEVER!!! THERE IS NO GROUND. It provides NO PROTECTION NO SENSE NO CIRCUIT TO GROUND FOR THE UPSTREAM GFCI TO DETECT. YOU ARE DANGERIOUSLY MISTAKEN!!!!"
If a GFCI trips and is wired properly, ANYTHING on the load side will be deenergized, whether a ground is present or not.
If you do a simple test on an ungrounded receptacle downstream of an ungrounded GFCI by placing a load between the hot side of that receptacle and the neutral side of another circuit, the gfi will trip. THAT'S BECAUSE A GFCI DOES NOT REQUIRE A GROUND TO OPERATE! If a GFCI does not require a ground to operate, how can you make this statement?
BILL: GO BACK TO
http://forums.taunton.com/tp-breaktime/messages?msg=53896.37
and at the bottom CLICK the link "view ENTIRE message" then READ THE WHOLE THING, and the references and links fella, THEN lets hear from ya! I still can't believe you think that anything following a single GFCI receptical in an UNGROUNDED 2-wire situation is protected! we're specifically NOT referring to a grounded neutral at the panel here, I'm just AGAST you would not only say to me, but in your prior posts on this string!!!!! Where did you learn electrical theory? Cracker jack box?
From what you post I can tell your not an electrician. You seem to have mastered some of the subject but lack a practical grounding in it. I see the same thing when EEs try to tell me how a MCCB functions and how it can't exceed its face rating. I could cite reams of manufacturers data on reaction curves and let through current. But why. Not to say they are dumb. They just have little practical understanding of how theory translates into reality. You quote well known and understood sources without understanding they don't back your central premise. You put forth a claim of electrical tape having some utility as a barrier to RF radiation. Sorry, but on this narrow point your wrong. Until you can point to some authoritative source to show otherwise I'm not going to buy it. You can post sources till the cows come home but unless they actually deal with the actual issue your not going to get much traction.As for RF energy damaging GFIs the sources you post say it is a possibility. They, as far as I can tell, don't cite a cell phone as being sufficient to cause any actual damage. The studies being laboratory and theoretical in main. Reference the article and they don't seem to mention the RF signal actually tripping the GFI. Which is what the thread was about. That the RF signal may damage the GFI is a separate issue. An issue which remains to be seen in this case.On a more practical level I have not noted any greater failure rate of GFIs in areas which could be expected to have higher levels of RF or microwave radiation. Such as areas surrounding antenna farms, cell towers and Ham radio transmitters. What I have found is that GFIs, as with most things tend to eventually go bad. I suspect line surges and corrosion as being a far higher source of attrition than RF radiation. While it is fine and good to make note of improved standards for UL listed devices it really doesn't make much difference in the field. This sort of thing is more worthy of a footnote than a parade.Further to berate Mr.Hartmann as to proper wiring of a GFI is laughable. Most competent electricians don't 'back wire', push wire, anything. Most GFIs do not have provisions for what you are terming back wiring. The majority of GFIs have screw operated clamping devices which are rated at more than the wire itself. Re: "I still can't believe you think that anything following a single GFCI receptacle in an UNGROUNDED 2-wire situation is protected!" As typical your careless use of the term "ungrounded 2-wire situation" leaves a lot open. If your referring to an ungrounded conductor, hot leg, lacking a power source would make it safer. If your referring to a box lacking a grounded conductor, a neutral, there is some concern. If your referring to an ungrounded receptacle because the box lacks a ground then your simply wrong. See the 2002NEC, the 2005 is similar I believe but it isn't at hand. Article: 406.3 (D) specifically 3b and c.You really should consider what a GFI is designed to protect and exactly how it does so. A ground at the receptacle is not necessary for a GFI to function as it is measuring the current differential between hot and neutral by way of a single winding around both. On a more serious note your condescending tone and unwarranted familiarity is not helping your cause. In fact it undermines your credibility. Mr.Hartmann has been and done. He has a long history of posting well thought out opinions and arguments. I have never, to my knowledge, worked with him but I can tell he has considerable hands-on practical knowledge of the subject and a deep theoretic understanding. I both value and respect his opinions. Given your extensive history, 6 posts when I checked, and apparent inability to cull and focus the materials you reference I don't think your in any danger of overruling his authority.If you are associated with actual building of anything, something I doubt from the tone of your posts, you may find that respect given is often respect received. Reputation is earned over time. Go to a job site with a condescending attitude and you will be ignored. Do it too often or too strongly and things can get downright mean. I have seen more than one EE get booted from a job.
Well said!
Ell, please go find out how GFCIs work. They DO NOT require a ground to "protect" the outlet (though they do require a ground for the test button to work).And though there may be code prohibiting it (I don't know), there's no technical reason why a GFCI on an ungrounded circuit could not be used to "protect" downstream outlets. (This is exactly analogous to plugging a 2-wire extension cord into the GFCI outlet.)GFCIs contain a torroid current transformer, and both the incoming hot and neutral wires are wound around the transformer core. Another winding on the transformer feeds an electronic amplifier. If the hot and neutral currents are PERFECTLY balanced then they cancel each other out and the other winding detects zero current. If either hot or neutral comes in contact with something grounded, even through a fairly high resistance, some current will flow to ground, imbalancing the transformer and causing the electronic amp to pick up a signal.If the amp detects any signal (over a minimal noise level), it triggers a solenoid that disconnects the power.Note that the only "ground" required here is the one that causes some ground current to flow -- eg, the person who is in danger of being electrocuted. If they're not grounded then no current and no danger. If they are grounded, then it imbalances the torroid and the GFCI trips.
"And though there may be code prohibiting it (I don't know), there's no technical reason why a GFCI on an ungrounded circuit could not be used to "protect" downstream outlets. (This is exactly analogous to plugging a 2-wire extension cord into the GFCI outlet.)"Actually the code sepecificaly allows that as a way to legaly replace old non-grounded style receptacles with ground style and with no ground connection. But they need to be labeled as such.
Old Ungrounded 2-wire systems, replacing recepticles either 1) replace GFCI circuit breaker, and install all regular grounded type outlets in the circuit labeled NO equipment ground, OR replace ALL the recepticles with GFCI type recpticles and label NO equipment ground, or replace them with ungrounded original style outlets.
if you replace just ONE recepticle in the circuit it will react to a GF occuring at THAT location and YES de-energize the circuit "downstream" IF all wiring is correct AND there is NO SHARED NEUTRAL in THAT circuit (with a neutral in another). IF there is a GF occuring AFTER that GFCI recepitcle lets say 10mA (enuf to cause interruption in regular heartbeat of an adult) the GFCI MAY NOT REACT at all, or within the specificed time. IF there is a shared neutral on the circuit -- it may NOT properly de-energize the circuit. Real life testing and recepticles IN USE in other areas will prove this. NFPA had a nice report using 90-98 stats in preparing the original 2002 NEC and the details regarding fire investigations were quite informative in this respect, both in home electrocutions as well as home fires.
You confuse ACTUAL microwave energy, and 900mHz frequencies, I said was nearly microwave. and it will deflect the phone signal. Try it you'll see. Bill mentioned metal tape earlier, and I've never seen electrical tape that had ANY metal componant.
IT is NOT the windings thats being effected: its the electronic componants and the specific frequency of this particilar RF energy that is being effected, that and the internal connection (micro board) that is.
Certain GFCI recepticles, especially older ones, have a flaw in which their electronic componants respond/react to CERTAIN frequencys of RF at certain levels (i.e. cell phones) and cause nusiance tripping. Unfortunatly THIS exposure's effects (the causing of the nusiance tripping) also damages over time and exposure the components themselves that are reacting to this, rendering the GFCI recepticle unreliable in its ability too detect and react properly to 5mA differential in a timely manner, yet these devices CAN still respond correctly to a manual test-button test.
thats what UL found, and warned about nearly a year ago. That's what that release was all about. OP's original post and his follow up went on and on about, and he moved phone, and original no prob, but started tripping another one.
I referred to the ENTIRE section of UL and Bill, you saw where your first cite allowed screw type connections only, said (tested) then your second citation was a list of what WAS NOT TESTED (therefore not allowed). it was I capitalized the NOT part for you, I think you still miss the NOT.
1) multiple conductors cannot be attached under a single terminal screw. 2)if multiple conductors, can either wire nut them with pig tail and attach using a screw post, or 3) utilize both back and side screw posts one for each conductor, that's what its saying.
Bill previously was quoting from 1999 NEC, 2002 is better, but 2005 ed. of thr 2002 NEC is re-numbered and clarifies this even better. Please consult the ROPs and you'll see. Just like the black letter law says one thing the court cases have to be reviewed as well to understand the pratical aspects of the law -- same thing for the code. Best way to understand just what IS and isn't allowed and why, to decipher the meaning of it, and how multiple areas effect, and that no one section ever stands alone -- is to review the proposed changes, and review the discussions and voting behind it. I completely stand by that code does not allow for recepticles or switches to be spring clamped when through to another outlet, only end of run can be and maintain code. They also repeatedly have addressed (various CMPs through the years) whether or not they would disallow entirely the use of those spring stabs in boxes, esp for ground, the last published ROPs still hadn't passed that yet, so I'll be interested to see how they settled for this latest edition -- but there has been a real push within to require always to be screwed down within the box -- last I saw 2 CMPs passed, but ultimately overall the proposal failed.
I'm sure Bill knows that you can take all UL listed componants with different tolerances and put them together with all kinds of varriances and end up with a combined weakness, that individual components don't exibit -- that's what we're talking about here. I'm sorry that you don't see how that one fix can reduce but still doesn't protect from what enters and effects from the FACE of the recepticle, but it does AT that particular frequency range.
Enjoy. You all apparently still dispute what UL found in extensive field studies, regarding this very issue effecting CERTAIN GFIC recepticles. That was the point plain and simple, said it from the first. IF OP's wiring is correct, AND his GFCI recepticles are pre-Jan1,2003 listed (or oh no! from that group of Jan-sept 2003 recalled ones), and he replaces them with post and non-recalled Jan 1,2003 listed/manufacturered ones, AND he uses the terminal screws, and he wraps them before pushing them back in the box for installation, AND he has proper face plates (usually non-metalic for kitchens - not going into when and how those exceptions work) for his kitchen counters he shouldn't have this problem anymore. However, as cell phones are often dropped, there could also be the possiblity that the phones own limited required shielding isn't perfect either, so keeping it at least 6-12 inches away from the face of the outlets - and not pointing at the face, should work fine for the future. The fact that these recepticles had repeatedly tripped from the phone (later OP stated problem had been going on quite some time he later learned from wife) irregardless he needs to replace them. Lets agree to agree that whenever GFCI's are tripped save the manual testing, for whichever reason (actual GF, power surge response, electric company's equipment failing somewhere into yr home, etc.) this reduces the useful life of the GF detection circutry, and expidentially "ages" it to what degree no one really knows as your own mileage may vary.
Frankly with them so VERY CHEAP these days compared to when they were first offered -- I can't ever see a reason to NOT replace them if all other investigations provide no results. Sometimes replacing the circuit breaker for that circuit with an AFCI one will INSTANTLY go off, and one has to track down where the problem is, strangely have seen many "journeymen electricians" fail to find the problem until that is done. Had ONE grounded type duplex recepticle in a room "downstream" from a GFCI recepticle, where only one of the recepticles had a problem that was only found when something was plugged into it with a modern 2-prong cord (directional), after swapping the circuit breaker with an AFCI one (square D) when that was done, no GFCI trip, just ARC FAULT, bingo.
when bill got into why I brought up arc faults I didn't address it. Was because I was considering the fact that originally the OP brought this up in conjunction with his CELL PHONE CHARGING UNIT. some of these are simple transformers that directly plug into the wall and then run a line to plug into the phone (some are socket type some are "pin type", and some of these units are contained in a holding stand and then run a longer cord to the recepticle -- and sometimes these charging units can be the source of a problem (arc fault) most commonly if they are of the long cord from the base type not the plug in transformer then cord to the phone type, however I dropped that when we learned that the phone seemed to be causing the tripping when phone ON, and even when the charger was not present at all.
I will look up the references from committee reports (both NFPA and UL) regards to the problems with GFCI recepticles when wires crossed or neutrals sharred elsewhere in the circuit, but this is WHY UL changed standard 943 for those manufactured on/after Jan 1,2003 to address this problem (trips shuts down rest of circuit, yet face can remain energized - old style, SOME designs).
Bottom line: Cell phones can trip certain GFCI recepticles -- mostly older ones. If that's the case -- ya need to replace them with the newer style that are required to be more resistant to environmental noise and RF interferance. Its best practice for many reasons to wrap your outlets. It does actually deflect certain frequencies and prevent the conductors from picking up same when idle.
"if you replace just ONE recepticle in the circuit it will react to a GF occuring at THAT location and YES de-energize the circuit "downstream" IF all wiring is correct AND there is NO SHARED NEUTRAL in THAT circuit (with a neutral in another). "Again you are throwing some completely out from left field. Shared neutrals have nothing to do with this discussion."You confuse ACTUAL microwave energy, and 900mHz frequencies, I said was nearly microwave. and it will deflect the phone signal. Try it you'll see. "Actually based on the standard long used to define the eltromagnetic spectrum.long wave 30kHz - 300Khz
medium wave 300kHz - 3 mHz
short wave 3mHz - 30 mHz
VHF 30mHz - 300 mHz
UHF 300 mHz - 3gHz
SHF (microwave) 3gHz - 30 gHzActually the common micrwave oven operates in the UFH and not microwave frequency.So 900 mHz is not even near microwave."IT is NOT the windings thats being effected: its the electronic componants and the specific frequency of this particilar RF energy that is being effected, that and the internal connection (micro board) that is."And exactly what is this "specific frequency". Does it work on 890 mHz and 910 mHz. What about 850 and 950? What about 800 and 1000? "1) multiple conductors cannot be attached under a single terminal screw. 2)if multiple conductors, can either wire nut them with pig tail and attach using a screw post, or 3) utilize both back and side screw posts one for each conductor, that's what its saying."No that is not what is says.There are TWO (2) DIFFERENT connection methods where the wire connect through the back of the device instead of the side terminals.Those two methods have very differnt characteristics, limations, and specification about how they are used.I think that you have been mixing them up all the time."I referred to the ENTIRE section of UL and Bill, you saw where your first cite allowed screw type connections only, said (tested) then your second citation was a list of what WAS NOT TESTED (therefore not allowed). it was I capitalized the NOT part for you, I think you still miss the NOT."The first section allowed not only screw terminal connections, but also the TWO (2) DIFFERENT menthods of connects via the back of the device. And all 3 methods, when properly used, can be used for feed through."Certain GFCI recepticles, especially older ones, have a flaw in which their electronic componants respond/react to CERTAIN frequencys of RF at certain levels (i.e. cell phones) and cause nusiance tripping."Actually ALL electronic equipment is subject to mis operation and potential damage depending on the frequnecy and power levels. And just because a certain level caused mis operation that does not mean that the device was damaged and will not operate correctly after the RF signal has been removed.Now if you had said that the testing levels for RF susceptibility had been raised I have not object to that. However, none of the stuff that you posted says that.But even if that is true it does not eliminate the problem. Just sets a level for it.
Re: "I'm done trying to educate you three on this subject. obviously the OP solved his problem or fried himself. I sure DO hope he got himself a MODERN replacement GFCI receptacle for each area he wished protected to the extent and level he required protection."
You post multiple copies of essentially the same information. Never mind actually culling your links of pasting from them to point out what you feel is the relevant part/s. Of course it helped that it was old information that I was well aware of. But clarity was not your goal.
Simple fact is you have no idea of what your talking about. Perhaps you could "get your Azz" out of the library and actually find out how all those things you read, but don't understand, actually apply to reality.
Your contention that electrical tape will stop RF signals was so laughable as to demand response. You could have admitted it as such, had a good laugh, and moved forward. Your continued need to add more information is a lame attempt obscure this glaring error and a wider general ignorance.
You cite 2003 standards. Last I looked we were well into 2005. Have to check my watch. But you cite this as if it has some bearing. Never mind all the major manufacturers have adopted these standards. They want to reduce susceptibility to noise, interference and overvoltages fine. Improvement is good. But I didn't see any great need. Haven't seen a lot of failures in those modes.
Your claim downstream receptacles aren't protected. That a circuit without a ground isn't protected. Both are just plain wrong. Get your Azz out into the field and give it a go. Surely you could actually get a GFI or two and actually check what goes on. I spent, spend, a lot of time with books, I'm more comfortable with treeware than computers, and in libraries but actual hands-on experience would show how utterly foolish you are making those claims.
Your desire and need to sidestep your ignorance by adding the separate room and completely unconnected reverse wiring verbiage is telling. Any electrician worth his salt would know that a reverse wired won't set. It is the way they are designed. Of course any electrician, as opposed to electronics dabblers like yourself, would check his work. Your explaining reverse polarity was redundant to what I teach first year helpers on their first day. Checking for reverse polarity is part of any installation. A professional checks his/her work.
Re: "Be stupid, I don't care. Just hope you don't kill anyone ELSE by your stupidity."
I do this work for a living. Have for many years. Went through five years of classroom training in the field. Studied under masters. Have many years in designing and assembling electronics as a hobby.
Further: If you wish to enjoy anything but a passing acquaintance with your teeth I would suggest you stay in the library and avoid saying anything resembling that remark on an actual job site.
I'm a pretty tolerant guy but I suggest you go out and actually learn something before spouting nonsense. Patronizing and feigning to teach people who know what you do not just makes you look silly.
To date your contributions to this thread can best be characterized as: ... "it is a tale told by an idiot, full of sound and fury, signifying nothing."
Maybe you will do better in the future. Then again my grandmother might grow wheels and turn into a Western Flyer.
It took over 24 hrs after I complained, but I see that the moderators have deleted "her" last post.While it was directed to you it was full of insults to me.I have just cooled enough to respond.And it was not going to be purdy, even after I "cooled" off.I say she, becaue I found some posts of at bobvia.com under the name MistressEll.http://www.bobvila.com/BBS/Electrical/4535/4592/tree-page1.html"My 2005 NEC must be missing a few pages. There are no appendix H, there isn't even an Annex H. Also, 240.100 applies for voltages greater than 600 volts.I've also noticed in my code book that a motor home is not a mobile home, it is a recreational vehicle, and has its own article (551)I admit that I assumed the original poster meant UF cable when he referred to buried Romex.I am still looking for the requirement for ground fault protection as it regards 30 amp 120 volt circuit for this type of installation at a dwelling, or other type of property.Also, Table 2 in Chapter 9 deals with bending radius of conduit or tubing, how does this apply to the posters question?I feel that a 10-2 UF cable, connected to a 30 amp breaker at the source and a 30 amp 125 receptacle at the motor home without GFI protection is in compliance with the NEC, 2002 or 2005.I thought maybe April 1st had come early :-)"
Some folks seem to be so very proud of their ignorance that they feel the need to proclaim it loudly, in no uncertain terms, and spread the news on as many sites as will allow their baying at the moon.Have to like certain aspects. Electrical tape as an RF shield was interesting. He, she?, must live in one of those 'alternate' universes where the laws of physics, and from what I gather given the arguments offered logic also, work differently.Kind of disappointed the response was deleted. I'm not hanging here as much. Without the woodshed I have to make an active effort to visit this site. Would have liked to see it. I think Ell likes you. I was throwing static his, her, way and the insults were still getting thrown your way. If anything you were the nice guy. Makes me wonder what Ell was expecting. Going to a construction forum where people who do the work are and try to 'educate' them that what they do and what they know is wrong. When they don't bend their knee and tug their forelocks to his/her 'superior' understanding accuse the residents of blatant ignorance and killing people through their incompetence.Doesn't read like a likely method of winning friends. Or even exchange views.I was only half joking when I posted that showing ones behind in such a manner on a lot of sites could get painful. I would appreciate it if the next time something like this happens someone make a copy of the post and perhaps e-mail it to me. Nothing like an incoherent rant to get the blood going first thing in the morning.I must say Ell had certain redeeming value. What he/she lacked in technical and practical skills was more than made up for in entertainment. Not sure Ell would see it that way. I don't think that was the intended effect.
You did not miss anything.The message that was deleted was #71, the one that you replied to.While it was addressed to you I was called out by name several times in it and the insulates where directed to me.Actually they where fairly mild. And as you said there is a certain amount of entertainment value in her posted.But after a while the the "dumb act" just got to me.I would have probably gotten myself kicked off with some of the things that I was thinking.Unfortunately I don't think that the "dumb act" as an act.One thing is that I wonder where he/she got their "expertise" from.
That post on the Vila site your cited read like Elll did here. Ran a few searches For MistressEll over there and, other than the GFI issues and NEC confusion he/she made some sense on a smoke detector thread and can lights, I think it was can but didn't read it closely, in a basement.I don't remember anyone, could be a local thing, recommending changing batteries Twice a year, one a year is more than adequate considering modern batteries and the load a smoke detector draws and a reasonable tradeoff between cost, trouble and safety, but changing them twice a year won't do any harm. Unless you fall off a ladder.Seems Ell can be almost lucid. Why this would vary, thorazine dosage?, is anyones guess. Seems he/she is a little hyper sensitive to electrical risks.Where Ell got his/her expertise? Anyones guess. Reminded me of a cross between how electronics experts tend to sound when they try to do line voltage wiring in a building and some shades of a few people who take a three month course to 'become' electricians at the local community college. The later part is all book and no field training. They come out mighty 'green'. Tolerable to work with as long as they keep their moths shut and ears open and don't try to 'educate' the crew. Takes another year or three practical hands-on experience to make a decent electrician.
Around here they recommend a battery change for the smokes scheduled with daylight savings. If I remember correctly the promote it both in the spring and fall.Here California recommends twice a year;" A final note, especially in that one of my uncles was a fire chief in Connecticut, my step son is a firefighter, and one of my colleagues has a family member who is the former fire chief in Sacramento...with the change of Daylight Saving Time, it's a good time to change the batteries in your smoke detector(s). Changing the batteries twice a year will make sure that the detector(s) will be working in case there is a fire. Some inexpensive detectors also need to be replaced completely about every five years or so. Also make sure you dispose of the old batteries and alarms properly. Check with your local solid waste disposal company or waste management board to find out the best way to dispose of old batteries and the alarms."http://www.energy.ca.gov/daylightsaving.htmlAnd here is another.http://www.vbgov.com/dept/fire/lifesafetyprograms/0,1634,9706,00.htmlOthers seem to be once a year, but even on those many of them are show as press releases and it might be just for the last season they where released for.