Hello all,
My rural property has a 220 service some distance from the main which is used to power a water pump. I would like to create a 110 service at this location. The problem is that whomever installed this pump only brought out a two wire plus ground. The ground is an open NOT insulated wire.
Is there any way for me to be able to split this and create a 110 service? I don’t seem to have a common.
thanks.
Edited 12/17/2007 11:23 am ET by venetogardens
Replies
Welcome to Breaktime.
Many Electricians will tell you you need to run another wire, per the code and all that.
However, Since your ground is an insulated wire, you can use that as the neutral. If your well or water pump has a good ground, then that can be used as a ground.
Failing the existence of a ground, install GDCI outlets for the 120 V, using the present ground as the white wire.
This is not per code, but own opinion is that it works and is safe; however, since you needed to ask in the first place, it infers an unfamiliarity with electricity, and the method is not FOOLPROOF. Hard to get into a dangerous situation with GFCI installed however, put them on the feed to the light circuits also, ahead of any light switch. Expect nuisance trips occasionally.
Any opinions given above are only opinions and do not reflect any local codes, etc.......
Hello Junkhound,
thanks but I made a typo in my request. The ground is NOT insulated.
I have edited my message.
How much power do you need? A transformer may work.
If you only want one 120v circuit at the present 240v location, you can use one of the current hot legs as a neutral.
Remove the 2 pole breaker serving the current circuit and install a single pole breaker, Use one leg of the old 240v circuit as the hot for the new 120v circuit, and the other as the neutral. Leave the bare ground in place. Mark both ends of the new neutral with white electrical tape to indicate its' new use.
If you want two 120v circuits out there.
Pull new wire.
Dave
Edited 12/17/2007 12:32 pm ET by DaveRicheson
VG,
Not the news you want to hear, but there's no two ways about it--you have to run another wire to get 120V at the far end.
For any one else's future reference, as far as junkhounds suggestion (which was correct, based on the fact that the grounding conductor was insulated, which you clarified to indicate that it is not)--there are some additional issues to consider:
1. running a three wire feeder (with insulated wires--hot, hot, and neutral) to a location to provide a 240/120V circuit is OK per Code, but the overcurrent protection of the feeder would have to be no more than 20 amps for the 120V circuit if you're intending to install a regular 15 or 20 amp GFI receptacle outlet.
If the pump protected by a breaker of more than 20 amps, you'd need to install a small subpanel at the pump end, which is no big deal--there are inexpensive little four-breaker-space 4R (raintight) panels available.
A remote subpanel like this is considered a separate structure, and although it's providing only two circuits, it has to have a grouding electrode. If the well casing is steel, that'll do quite nicely. If not, drive two, 8 foot ground rods.
This approach--no equipment grounding conductor in the feeder between the two panels--is OK only if there is no metallic pathway between the two "structures", i.e., the building where the power comes from and the post or whetever the subpanel is mounted on. SO, if the water piping 'tween the pump and building that power comes from is plastic, this approach is OK. If it's iron or copper pipe, or there's a phone line or any other metallic path, it's a Code violation and can under certail conditions, be dangerous.
2. With the three-wire feeder approach described above, be careful at the supply end. If the power is being supplied from the service panel--where the equipment grounding conductor and the neutral (grounded) conductor are bonded (connected), the feeder neutral is connected to the neutral/ground bar.
To clarify, in a given building, the neutral/ground is the same only at one point, the service point, basically at the main disconnect/main panel/utility meter.
If the three-wire feeder is supplied from a subpanel that has separate ground and neutral terminal bars, and the neutral bar is properly NOT connected to the grounding conductor (a "floating neutral"), the feeder neutral is tied to the subpanel neutral.
What if the feeder supply is a subpanel in the same building as the service point and the ground and neutral in the subpanel are bonded? And I see it a lot, even though Code has required electrical separation of subpanel ground and neutral for a long time, at least 30 years--basically when equipment grounds became required for branch circuits.
Then my opinion is that you can't supply a 240/120V feeder from that subpanel. Tying the feeder neutral to a grounding/neutral termianl bar would, in effect, be connecting a current-carrying conductor, the feeder neutral, to the equipment grounding conductors at the subpanel. That's a Code violation--the only point grounding conductor and neutral conductor meet are the service point (or under certain condition, at a separate structure subpanel, which is sort of the service for that structure).
What's the problem with connections between the grounds and neutrals? An interruption or partial interruption of the neutral to the supply subpanel, and there would be a voltage on the grounding conductors. Imagine having 120V on the metal housing of a grounded tool or light fixture...
Now, the potential for that condition exists anyway in a subpanel with the ground and neutral improperly bonded, but adding a 240/120V three-wire feeder to a non-compliant subpanel is not right, and more importanly, it's not safe.
It would've been good if the installer had run one more wire in that pump feeder, eh? Remember, though, that it's all about the money, and running one more wire that you don't need to run a 240V pump, puts the installer at a competitive disadvantage in bidding.
Good luck,
Cliff
He is saying "service", but maybe he means circuit.
That is an assumption on my part, and why I said to remove the two pole breaker at the main panel and replace it with a single pole breaker.
Maybe he will come back and clarify things.
Dave
Dave,
I figured he meant circuit.
Your idea to convert the circuit ot 120V is an excellent solution, I just figured that the pump was 240V...it could possibly be rewired to run on 120V.
I had a remodel job the other day, the old part of the house was being demolished, and of course it had the electric service and main panel on it. The remaining part of the house was served by a zinsco panel (in a kitchen cupboard) that was a disaster. Had to provide temp power to the part of the house that was to remain. Temp pwr pole in the front yard of the house, triplex over the house to another temp pole in the back yard and 2" sched 80 to the house and a 100 amp temp panel on the back of the house. Big j-box, and extend the 8 circuits to the new sub panel.
The real fun part was the swimming pool feeder. A normal 20A, 240V ckt underground in pipe (schedule 40 irrigaton pipe, oh well...) to a pedestal w/timer/controllers for pool filter pump etc. About 100 feet from the house. At the equipment area, there was the GFCI receptacle outlet to run the pool cover...to get 120V, some goofball had bootlegged a neutral from the equipment ground! I told the homwowner he was lucky, if the EGC had been compromised, the metal pool surfaces (railings, rebar, etc) would be at 120V!
I thought about converting the pool cover system to run at 240V, but it wouldv've required not only a new on-off relay (no big deal), but also a 240V hydraulic pump reversing relay...this was gonna cost over $300 (if one is even available--it's an old system).
So next spring, it'll be my job to run a proper 240/120V feeder out there. Might be able to do it in the existing conduit, we'll see. The fact it's irrigation pipe suggests that the elbows are tight 90s and pulliing in new wire won't be feasible.
Remodels are never boring.
Cheers,
Cliff
HI Dave,
I guess I wasn't using proper jargon. To clarify, I have 3 wires which run from my main breaker box to a 2.5 horse irrigation pump which is 220v. I need to keep this pump. There are 3 wires. Two of which are insulated and the third is a bare wire ground. The pump is a good 100ft from the breaker box and has a rather large concrete slab between. And before anyone asks, I considered running an extra line or use the existing line to pull a new line but the conduit looks too small and I don't trust that it was installed properly. For instance the bends done properly, based on other construction I have found while remodeling this house.
I was looking to tap into this at the pump switch box and put in a 110 GFCI plug to be used to maybe run a low voltage light transformer, christmas lights, or ???
I hope this clarifies the arrangement.
Hello CAP,
Thankyou for the very thoughtful reply. I think I am pretty well stuck. I am going to research the transformer idea.
Or I just have to do a whole bunch of trenching to go the long way around the driveway. I am not even going to try and tunnel under 40ft of concrete. I know it could be done.
Cheers,
dave
Why not get a florescent light with a 240v ballast?
Jack
I want to us this 110v plug for hand tools or run a low voltage outdoor lighting system. As I've said above, I need to keep my 220v irrigation pump. It is used to irrigate the pastures.
I must of had a brain sieze. Got it in my head you just wanted to add a light. Jack
"1. running a three wire feeder (with insulated wires--hot, hot, and neutral) to a location to provide a 240/120V circuit is OK per Code, but the overcurrent protection of the feeder would have to be no more than 20 amps for the 120V circuit if you're intending to install a regular 15 or 20 amp GFI receptacle outlet. "If this is treated as a separate structure with no metalic paths can't you treat the whole as a service entrance (IIRC the panel needs to approved to as such) can't you use a uninsulated neutral?.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
"It works," and similar sentiments, are the bane of the trade. This is how thing go wrong. The whole reason there's a problem now is because some cheapskate used that sort of logic in the beginning, and did as little as possible. The result of that false economy is that today his options are limited. Our own government statistics rate farmwork as being one of the more dangerous trades out there. big part of the reason for this are the sundry 'it'll work' repairs that are found on farms. If he's adding a load, he likely needs bigger wires anyway. As for terms .... It's not a service unless the PoCo has a meter there. It's a circuit. I don't care how similar it may appear to the multiple service drops you see between houses .... the presence of a meter, and PoCo ownership of the wire, are integral to the definition of 'service.'
farmwork as being one of the more dangerous trades
Knew/know 6 farmers with mishaps, none were electrical
1 died when a hay bale rolled over him
1 died when a tractor without rops rolled over him
Cousin had a finger bitten off by a Hog (not Ron, but a meaner Boss Hog critter getting sent to market, somehow those pigs know)
Uncle lost a hand in a corn combine
One lost a hand in the fan of a tractor
DIL cousin, crushed foot in a grain auger
Ah heck, add #7, me getting head caught between a tree and a dozer, wye eye caint spel. <G>
Only have known 4 people hurt electrically, 2 died when a large lithium thional chloride battery exploded, another in a lightning laboratory not following safety procedures properly, father of co-worker killed when a supervisor closed a substation breaker without proper authorization.
Edited 12/18/2007 2:01 pm ET by junkhound
Bill,
Nope.
NEC sez, any current-carrying conductor has to be insulated; see 2005 NEC, 310.2 (A), which reads,
"Conductors shall be insulated", with the exception "where covered or bare conductors are specifically permitted elsewhere in this Code". The primary exception is for equipment grounding conductors, which, in normal operating conditions (i.e., non-fault conditions), are not current-carrying.
An aerial or overhead service drop typically has a bare neutral because it's on the power company side of the meter, and things on the PoCo side of the meter are governed by the National Electrical Safety Code (NESC), not the NEC. Practically, if the clearance requirements for a drop are met, there's little chance of anyone coming in contact with the bare neutral, aluminum extension ladders aside.
I'd be willing to bet that the NEC has never allowed un-insulated neutrals in interior building wiring. I believe that the use of service entrance cable with a bare neutral to supply an electric range was a violation of the Code the day it was installed. Is it inherently unsafe? Under ideal conditions, no. But a lot of the code requirements are based on "what if" scenarios--what if something is damaged or fails, will a dangerous condition then result?
An example--GFCI protection. If all branch circuits had really good (low-impedance) equipment grounding systems, and all appliances and tools and fixtures had well-maintained grounding cords and plugs, then GFCI protection would provide no additional safeguard against shock or electrocution. But we can't count on every equipment grounding conductor splice to be perfect, and we can't count on the ground pin on every cord to remain undamaged...so GFIs provide a way to save lives.
I'll whole-heartedly second Reno's sentiment, there are a lot of times you can cut corners and have some electrical installation work and actually be safe as long as things don't change. But should something change--either through entropy (corrosion, loosening of a terminal screw or splice, gravity or vibration causing wires to touch, insulation damage or degradation), accidental damage, or intentional disturbance--then you can have a hazardous or deadly condition come to exist.
Want an example? In 2004, in my neighborhood, a 9-year-old girl was electrocuted at a self-serve car wash when she touched a metal light pole. There was no equipment grounding conductor; the contractor who installed the lighting figured he'd drive a ground rod at each pole and ground the pole to that. Later, a ground fault developed in the pole. The pole was impressed with 120V. The circuit breaker didn't trip, of course, because the path through the earth back to the panel did not provide a sufficiently conductive path to pass enough current to trip the breaker.
There are other documented cases of people being electrocuted by metal light poles that aren't properly bonded to the circuit equipment ground.
The point I'm trying to make is, the requirements of the NEC have been developed in response to specific problems, often after a tragedy has or tragedies have occurred.
The purpose of the Code is "the practical safeguarding of persons and property from hazards arising from the use of electricity". I don't discount the validity of a requirement because I don't have any direct experience in the area--because I haven't seen a tragedy occur as a result of a non-compliant installation--or because I think the chances of a problem occurring are below my risk threshold. I defer to the experts who developed the Code.
Merry Christmas--
Cliff
"I'd be willing to bet that the NEC has never allowed un-insulated neutrals in interior building wiring. I believe that the use of service entrance cable with a bare neutral to supply an electric range was a violation of the Code the day it was installed. "I don't know what the old codes said, bu tthe 2005 NEC specifically allows SE for existing installation."250.140 Frames of Ranges and Clothes DryersFrames of electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and outlet or junction boxes that are part of the circuit for these appliances shall be grounded in the manner specified by 250.134 or 250.138. Exception: For existing branch circuit installations only where an equipment grounding conductor is not present in the outlet or junction box, the frames of electric ranges, wallmounted ovens, counter-mounted cooking units, clothes dryers, and outlet or junction
boxes that are part of the circuit for these appliances shall be permitted to be grounded to the grounded circuit conductor if all the following conditions are met.(1) The supply circuit is 120/240-volt, single-phase, 3-wire; or 208Y/120-volt derived from a 3-phase, 4-wire, wye-connected system.(2) The grounded conductor is not smaller than 10 AWG copper or 8 AWG aluminum.(3) The grounded conductor is insulated, or the grounded conductor is uninsulated and part of a Type SE service-entrance cable and the branch circuit originates at the service equipment.(4) Grounding contacts of receptacles furnished as part of the equipment are bonded to the equipment."And the Handbook has this;"Prior to the 1996 Code, use of the grounded circuit conductor as a grounding conductor was permitted for all installations. In many instances, the wiring method was serviceentrance cable with an uninsulated neutral conductor covered by the cable jacket.
Where Type SE cable was used to supply ranges and dryers, the branch circuit was required to originate at the service equipment to avoid neutral current from downstream panelboards on metal objects, such as pipes or ducts."I did find where bare neutrals are allowed on direct burial or overhead feeder cables. But they limited to 1 kV and above. 250.184.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill,
You're right, SE cable with an uninsulated neutral is OK in specific applications and I should have checked before I wrote. I lose the bet!
When you look at an SE cable, the neutral is covered (by the sheath), and that isn't considered insulated. Here's an Alcan SE-R cable:
View Image
I'll do a little digging and see if the Code ever allowed a bare neutral in a branch circuit or feeder; I doubt it, but then again, I've been wrong before. Very recently, in fact. I'll ask the NFPA staff.
Cheers,
Cliff
Even if the ground is a bare wire, you can still do the GFCI thing. Of course that is NOT per code, but it works if you really need the 120V.
Of course, the transformer approach already mentioned is per code and the safest - check some on-line surplus stores (nebraska surplus sales, surplus center, etc) or ebay or even radio shack for inexpensive transformers.
Background of 3 wire, just for reference:
My grandma's old electric range that was installed in the 1920s had 2 insulated wires and a bare outside wrapping of copper strands.
The stove had 2 prong 120 V convienience outlets, fed from one insulated wire and the other side from the bare wire - This probably met code sometime into the 1950's? maybe revoked earlier.
From records I've been able to find on other investigations (dont ask for references, I wont give them) , there were on the order of 300 deaths per year in the US attributed to the arrangement of grandma's stove. Hence, electrical code went to insulated neutral required and more recently to a 4th wire required.
Own house was wired in mid-1970, dryer, range, etc. have 2 hots and a neutral, which is also used to ground the dryer cabinets - the 120 V motor in the dryer and range lights were run off current returning thru the combination ground/neutral. That changed in the last decade to 4 wires as statistics still showed a few electrocutions per year due to the 3 wire setup. (plus, equip mfg wanted to sell the more pricey 4 wire outlets)
GFCI will protect you if installed correctly even withthe uninsulated neutral.
BTW (again, dont ask for references) but numbers I've seen indicate societal costs for GFCI run well over a few million of total expense for each fatal electrocution avoided. Arc-fault will be even pricier cost/benefit ratio.
For 30,000 auto deaths per year against a few hundred electrocutions, an equivalent $50 billion or so could be spent making highways/autos safer or spent on genetic screen for early (under 50 YO) risk of heart attack. (my 2 cents worth)
Even the IRAQ war has a greater cost/benefit ratio than GFCI required everywhere. (that should start some discussion<G>)
Hello Junkhound,
Thanks for the good ideas. I am going to look into both the transformer idea. It seems a little safer. But I think either way if the GFI tests OK, then I would think it would be reasonably safe.
cheers
Sounds like you are on to some grand conspiracy! Keep up the good work
From records I've been able to find on other investigations (dont ask for references, I wont give them)
BTW (again, dont ask for references) but numbers I've seen indicate societal costs for GFCI run well over a few million of total expense for each fatal electrocution avoided. Arc-fault will be even pricier cost/benefit ratio.
For 30,000 auto deaths per year against a few hundred electrocutions, an equivalent $50 billion or so could be spent making highways/autos safer or spent on genetic screen for early (under 50 YO) risk of heart attack. (my 2 cents worth)
Even the IRAQ war has a greater cost/benefit ratio than GFCI required everywhere. (that should start some discussion<G>)
3 wire stove and dryer circuit where allowed by NEC until the 96 addition. But I understand that a number of local amendments disallowed it earlier.Now the stove receptacel is not covered by the NEC, but by the listing organization (most often UL). And I have no idea when that was changed, if it ever was. Maybe there just isn't a need for it so it has been discontinued in practice, but not in the standards."BTW (again, dont ask for references) but numbers I've seen indicate societal costs for GFCI run well over a few million of total expense for each fatal electrocution avoided. Arc-fault will be even pricier cost/benefit ratio. "While cheap per unti, I an sure that the cost benefit ratio for there latest idea will be worse.The 08 NEC requires that the receptacles be "tamper-proof". I believe that means some kind of sliding gate over the slots to make it child "proof".On the cheap residential grade (39 cents), which probably covers 96% of all 120 receptacles in a house I wonder how long it will be before these covers break and expose even more the receptacle?
.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I didn't catch how far the pump was from the house/main. You should also keep in mind the wire size. You can play with this on line calculator once you know the existing size and the distance to the pump. Others with more experince can tell you if it is accurate/correct.
http://www.csgnetwork.com/wiresizecalc.html
It may be that the original installer opted for 220v to keep the wire size down. Who knows what he/she had on hand... Even if you could safely spilt the service, you may have too long a run for 110.
Dean
Hello Healey, thanks for the link. It will be helpful for some other projects as well.
The nearest run is going to be about 80 feet away. Per the calculator should be #10 or #12 wire depending on the amperage.