I do remodels and though I leave most electrical work to the pro’s , I would like to know what is proper when I see it and then I will know if I should call in an electrician.
1. Why would any outlet be wired with 14 wire and a 15 amp breaker when any home owner could plug in a heavy power tool or high wattage device that seems to me will over tax the circuit. Isn’t it safer to go with 12 wire, 20 amp outlet and a 20 amp breaker in all situations?
2. Which leads to my second question: what causes the house lights to dim when a high amp tool is being used?
3. I am told it is dangerous to run 14 wire off of 12 wire leading to anything such as lighting. Should all low amp devices such as lighting be on it’s own circuit with a 15 amp breaker?
4. I would like to understand grounding more though I know of it’s importance. Do I understand correctly that electricity will take the path of least resistance and that grounding a device means less chance of a shock BUT the danger is still there, true?
5. It is confusing that the white neutral and the ground go to the same place (buss-bar) in a Electrical panel.
6. Is it true that a gfci outlet will make every outlet thereafter on the circuit protected? If so, why not start every circuit in a house with one to make every electrical device gfci protected?
7. Is it true that installing gfci in older homes without grounding wires will make up for grounding protection? If so, how are they installed without the grounding wire?
As you can see, I want to be sure for the safety of everyone involved!
Thanks
Replies
1) alot of people dont like 12 gauge because its thicker wire and harder to bend, pull and stuff in the box. plus 14 is cheaper
3) because its illegal to.
5)only at the main and not at any sub panels
6) one of the problem with gfi is. if they are wired in series and you pop one upline it will kill everything behind it. and there could be a refrigerator hook there. But thats another rule. refrigerator are on own circuit. suppose to be.
7) no
1. It’s not more dangerous to plug a high amperage load into a 25 amp circuit. The breaker will protect the circuit. It’s easier and cheaper to run 14 ga. wire if that’s all that’s needed.
2. When you plug a big load into a circuit the initial current is momentarily high, especially if the load is a motor. The high current causes a voltage drop (voltage = current x resistance). Usually the current drops as the motor reaches speed, and everything is cool.
3. I’ll let an electrician take this one
4. Grounding makes sure that things that are never supposed to carry high voltage, like casings and cabinets, are always electrically anchored to ground. An ungrounded casing could accidentally come in contact with a higher voltage lead and when you grabbed it and touched ground you would carry current and possibly die. Grounding also carries any fault current through to ground and if great enough, trips the breaker and protects from fires an electrocution.
5. True for the main panel. The key is that the neutral normally carries all the current. The green (ground) wire should only carry current to ground in a fault condition.
6. yes but see 3 above
7. see 3 above
2. Very few devices in a home, outside of the kitchen, require anything close to 20 amps. In general, you shouldn't have a larger breaker in a circuit than you need. And why use thicker wire than you need?
But #14 wire shouldn't be on a 20A breaker.
3. Given that lighting should be spread over several circuits, just so one tripped breaker doesn't darken everything, 15A is plenty for most lighting circuits (except perhaps in Bill Gates' house). (see #2)
4) Yes, proper grounding reduces the danger of electrical shock. But there are many ways to get shocked that have nothing to do with the presence or absence of a ground.
5) Don't think of them going to the same place. They conceptionally go to separate bus bars, but in some specific instances the two bus bars are "bonded" together.
7) GFCI's work by detecting a difference between the current going out and the current returning. If there's a difference it must be going somewhere else (ie, to ground, possibly through someone). So a difference between current in and current out trips the GFCI.
Rex Cauldwell, "Wiring a House", 226 pages, published by Tauton.
I did not know the ground ends up conecting to the neutral bus bar.
I recently discovered old wiring that each outlet ground was wired directly to the neutral (white) on the outlet. I didn't think this was right/safe but didn't know exactly why. If the ground and neutral end up conecting together at the box, than maybe it's okay???? Insight please from those who DO know.
Regarding the GFCI protecting outlets down the line, I think it depends on how it is wired.
-bob
If the ground and neutral end up conecting together at the box, than maybe it's okay????
No, it's not okay. A ground wired to the neutral inside the outlet is not a ground.
Remember how AC works, or find out if you don't know. (read the Taunton book suggested, or do a web search)
DC current flows one direction and needs no ground as it is a closed circuit between the generation source or battery and the device being powered. (This is why an "ungrounded" car with rubber tires still works) It has a positive and negative wire.
AC current is flowing back and forth 60 times a second (USA) between the hot and neutral leads. Your power company actually thinks of the earth as one of the "wires" in its circuit, and that's why the neutral connects to ground back at the panel.
No current should ever be present under normal circumstances on a ground. The ground is there to allow errant current to pass back into the earth without passing through you (or anything else) first. Electricity always wants to find it's way back to ground, and will always follow the path of least resistance. If the outlet is not grounded, then you risk becoming the ground should the box be energized when you touch it. Of course, this would only happen should something in the normal circuit go awry.
Grounds are also essential to some types of modern electronics which depend on them to function properly. (too messy to explain here)
Pictures will help if this is still unclear so try a book or a web search.
Edited 3/10/2007 1:50 am ET by Thaumaturge
1. remember that the circuit breaker is there to protect the wiring inside the walls and not the appliance plugged into the outlet at the other end. My county requires exactly what you say, 20a CB & 12g minimum. Why? Don't know. Wired correctly, 14g with 15a breaker is perfectly fine.
3. circuit breaker size is based on the size of the wire it's protecting. 20a for 12g, 15a for 14g. if you run 14g wire from a 12g wire, odds are the the 12g is protected by a 20a circuit breaker and will not trip when the 14g gets overloaded and needs the protection from the breaker.
5. may want to take a closer look at the panel. Look for something that insulates the neutral buss bar from the rest of the panel. I'd be surprised if they're routed as you say.
I'm not an electrician...
>5. may want to take a closer look at the panel. Look for something that insulates the neutral buss bar from the rest of the panel. I'd be surprised if they're routed as you say.<
This configuration (neutral / white and ground / bare to the same bar) is indeed the normal configuration in a service entrance panel. Typically the neutral bar is supported and insulated from the box enclosure by some sort of plastic bracket, however, if you look closely, you will find some sort of a bonding screw / rod which electrically connects the neutral bar to the metallic box enclosure.
The bonding rod / screw is usually removable to allow the same box assembly to be used as a subpanel. A subpanel, although at first glance may appear the same as a service entrance panel, is not exactly the same animal.
In very simplified terms a subpanel is an overgrown metallic wall box containing multiple switches (breakers) and huge wire nuts (buss bars). The wiring of a subpanel is handled very much like a metallic wall box - "line in" from the SEP comes in 4 conductor cable (2 hots, neutral and ground); the two hots go to the main lugs of the subpanel; neutral goes to the insulated, neutral buss bar (bonding rod and screw removed - no electrical connection between this bar and the box enclosure); ground goes to the ground buss bar (which is electrically connected to the metallic enclosure).
In a subpanel, when you are all done you will have a grounded enclosure; neutral, insulated from the enclosure; and a bunch of "switches" (breakers) which turn on-off branch circuits rather than individual devices.
Unfortunately, many panels are sold at big box stores packaged without any ground bars either installed or enclosed - the buyer needs to 1) know he needs one 2) locate it in the store and 3) buy and install it properly. Chances are there is no one there to ask the appropriate questions and advise the buyer - if he knows enough to ask. Knowledge is the key.
I'm not an electrician either but, the above I know to be true - our local inspectors and the NEC agree.
Jim
Never underestimate the value of a sharp pencil or good light.
I guess I ought to take a closer look next time I'm in a panel.
thanks for the correction
Another vote for that Rex Cauldwell book.
Harry
That is a must have for anyone doing electrical work. Top notch piece of writing. He also has a plumbing book coming out...
2. Someone already mention high amp draw when a tool is starts up as the reason for dimming lights. This is true in many cases, but there are other possible reasons. If the whole house is dimming when a simple power tool is started, it is indicative of other possible problems. The most likely being a loose neutral connection at the panel neutral bus, the meter base, the weather head splice, or on the pole at the transformer. Trouble shooting a whole house flicker should be done by a qualified electrician and/or the power company.
Lights dimming on a single circuit can also mean a loose neutral somewhere on that circuit. It can also mean that the circuit is severly overloaded. Agian a qualified electrician can run load test at the panel to make that determination.
4. So would many electricans. There is rather large article in the NEC that deals with grounding, and it is the most referanced article in the rest of the NEC. Trying to explain in lay terms for every situation is a rather daunting task.
6. GFCI will protect all other devices downstream of them on a sigle circuit.
Coming next year, 2008, the NEC will require AFCI breaker protection for all circuits in newly built homes. That is one of the proposed changes that seems to be a shoo-in for revision. Every time the subject is brought up at our trade organization meeting there is rather addament oppositon raised agianst the proposed change, but we ,the electricians and electrical contractors, know we don't stand a chance of being heard when the choir of electrical manufacturers is still singing praise to thier AFCIs.
Dave
Hey Dave, Are you talking about the electrical clearing house when you talk about meetings? I've heard a little about it but can't find any info on the web. Help me out here.
They won't sell you a gun if you are crying.
http://thewoodwhisperer.com/
I just looked. We don't have a web site.
The Electric Clearing House of Louisville. 502 627-3362
The number looks like an LG&E number. Probably to the secretary Marilyn Boudreaux.
Cost is $20/yr. Meet the second Monday of the month Sept. through April in the Label room of the Executive Inn Hotel (right outside the Fair Grounds) at 7:00p.m.
Attend four meeting and get 1.5 hr. CEU per metting for your license renewal. Beats the heck out of tieing up six hours on a Saturday once a year and cost less to boot.
Marilyn even sends the CEU certificates to the state each month, so you don't need to send in anything but your renewal form and the money each year.
If you also have a Contractors License you will need an addition 6 hours of CEUs that are not provide at the monthly ECHI meetings, but they do set up the courses. For Journeyman and Masters you get the required CEU at the meetings.
Dave
Very cool Thanks. I'm looking for a place to get together and pick up on what's happening as far as trends and techniques and what's coming, that kind of stuff. I'm pretty much isolated from the rest of the local electrical world because I'm the sole electrician at our company. And Frankfort has decided to stop posting their monthly electrical board meetings online. So I'm out of the loop as far as new local info. And networking.
I don't mind the CEU six hour class too much. I take mine through IEC the guy that does them puts on a real good class and I always get my moneys worth. And I always do them in January or February when the weather sucks anyway.
I've got the info and will call the number thanks.
They won't sell you a gun if you are crying.
http://thewoodwhisperer.com/
Edited 3/11/2007 9:06 am ET by Gunner
"2. Someone already mention high amp draw when a tool is starts up as the reason for dimming lights. This is true in many cases, but there are other possible reasons. If the whole house is dimming when a simple power tool is started, it is indicative of other possible problems. The most likely being a loose neutral connection at the panel neutral bus, the meter base, the weather head splice, or on the pole at the transformer. Trouble shooting a whole house flicker should be done by a qualified electrician and/or the power company."Is it most likely a bad neutral connections?Seems to me that is just as likely to be one of the hots. And while they say "whole house" I don't trust that as most likely they are only seeing a limited number of lights at any one time. Likewise I don't trust the "dimming". If it is a neutral 1/2 the lights will be increasing in brightness.And if it occures with the AC starts then the neutral can't be the problem.Also another potential cause is an overloaded transformer.When I hear of these kind of complaints I always suggest calling the POCO first as there connections are out in the weather."Lights dimming on a single circuit can also mean a loose neutral somewhere on that circuit. It can also mean that the circuit is severly overloaded. Agian a qualified electrician can run load test at the panel to make that determination."Or hot..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Yeah, the classic symptom of a bad neutral connection is that some lights in the house get brighter when a heavy load starts, while others get dimmer. If they all dim then a bad neutral is unlikely (or at least probably not the only problem).
It should be kept in mind, though, that lights dimming (when, say, the fridge or AC starts) in an older house with, say, a 60A service, is not (necessarily) a sign of anything wrong -- probably just normal wire resistance. Lights flickering randomly is far more worrisome, strongly suggesting a bad connection somewhere that may overheat and start a fire.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Someone recently told me (regarding electricity) that if it works, that's all they care about.
WRONG! There are many instances where something will "work" but still be unsafe.
Some examples:
I've recently had TWO separate instances where someone put in a single-pole switch where a 3-way was needed. They had three wires in the box, 2 brown, 1 red. On the switch, 2 brass screws, and one green one. 3 wires, 3 screws, no problem. Just hooke'em all up. Thank God that the breakers were functioning properly. This type of stupidity really ticks me off, since it is so unnecessary. Some day one of them will win the Darwin award.
Keep up the attitude of learning. I think it's great that you know what you don't know, and aren't afraid to ask questions or bring in the licensed guys. It should help you sleep at night.
There should be a selection of books at your local library you might find useful.
Pete Duffy, Handyman
One thing I think of when working with electricity is "be the electron." (you know, Caddyshack, "be the ball.")
Simplified electrical theory here:
Current is just a bunch of electrons moving through a conductor. Voltage (or difference in potential, aka electromotive force) is what pushes those electrons. Electrons, like water and humans, will seek the easiest path.
When I look at connections, I figure all the possible paths that the electron can take. This helps explain series and parallel connections, switches, etc.
And for current to flow, you need a closed path, or circuit. You want to make sure that you (or other unintended items, like the lamp post) are not part of that path.
And understand that in household wiring, the electrons should go from the panel through the hot (or ungrounded conductor), through the device, then back to the panel through the neutral (or grounded conductor). That's what it SHOULD do.
But what if a connection comes loose & touches something it shouldn't be touching? Then think of where those electrons would be, like troops amassed at the border, waiting for a path to go home. That is the purpose of the equipment grounding conductor, the green or bare wire, or around here in Chicagoland, the actual conduit itself. It's a lot more conductive than you are, so most, if not all, the electrons can rush back to the panel through that path, instead of you.
And if enough electrons are rushing through the circuit, it should trip the breaker. But you could still get zapped if not enough electrons rush through to trip the breaker.
Long-winded, I know, but I hope it helps.
Pete Duffy, Handyman
Pete,
The way you explained it makes the whole thing a lot easier to look at. The best thing to remember is the voltage is ready or waiting to go somewhere!
Perhaps the term "grounded" means more than one thing ( or at least used to say 2 diff things), that is a open circuit is grounded because voltage can move (whether it's through the neutral or our body), but when we say the outlet is grounded or has a ground wire, that does not mean the circuit is open but the system is best prepaired for safety when the circuit IS open (intentionally or by accident).
Thanks to everyone who has input!!!!!!!!!
I would caution against a common phrase used here a couple of time: "Electricity always takes the path of least resistance". Actually, electricity takes ALL available paths to complete the circuit - in other words, any path with a resistance less than infinity. Of course, the amount of current in each path varies inversely with resistance. But don't assume you are safe just because another branch of the circuit has the "least resistance". Consider an energized circuit that is just a single light bulb, and you grab a bare hot conductor while standing in water on a cement floor. The bulb is maybe only 20 ohms of resistance, and your body is thousands of ohms, but you still die because electricity flows through all available paths, not just the one with the least resistance.
Glad I could help some.
The term "ground" -ed or -ing basically refers, in general terms, to zero volts, and the actual earth is considered the reference for zero volts. (however, there can be a voltage difference from one spot in the ground to another some distance away, so even that isn't absolute.)
Your point is right on, that when voltage is present, it's ready to push electrons through something. It doesn't always have to be going to ground, just to a lower voltage. So even if you aren't grounded, you could inadvertantly be part of a circuit and get zapped. That's why a lot of people working with electricity keep one hand in their pocket. You could be working on an insulated platform or fiberglass ladder, not grounded, but if you put the hot wire in one hand and the neutral in the other, you've just made a circuit. Through your heart.
I saw on TV once where these linemen working in the field on the high tension wires actually hook themselves up to the wires, and now they are at something like 25,000 volts (or more, I forget the actual #). Since the line they are working on is at the same voltage, there is no potential difference between them and the wire, and they are safe (I guess as safe as that job can be!) So it's not the voltage, but rather the difference.
The next fun part you get to learn about is bonding. Have fun!Pete Duffy, Handyman
4. I would like to understand grounding more though I know of it's importance. Do I understand correctly that electricity will take the path of least resistance and that grounding a device means less chance of a shock BUT the danger is still there, true?
5. It is confusing that the white neutral and the ground go to the same place (buss-bar) in a Electrical panel.
Disclaimer: I am making some broad statements that are technically incorrect, but are true enough for a laymans understanding.
The Earth is always at zero volts, so you can't be shocked when your feet are at Earth voltage and the equipment is at zero volts (grounded.)
A complete circuit must exist between either of the hots in the panel and the transformer at the top of the pole. That wire is the neutral, or, return conductor. Specifically, it is called the neutral return conductor because it is the return for both hots. Since the PoCo uses the Earth as the return to the pole top transformer, the neutral is always at Earth's zero volts.
The neutral is always connected through a load to the hots, so if there is a problem it could be hot.
The green wire, called the ground, or more specifically the equipment grounding conductor is never connected to a hot unless there is a problem, but is still always at the Earth's zero volts.
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The white neutral return conductor and the green equipment grounding conductor are usuall connected to the Earth's ground rod through the same wire.
SamT
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. [Einstein] Tks, BossHogg.
As long as we are talking about grounds, there is something I got to wondering about. As some of you might remember from another thread, I had some scum buckets cut and steal the ground wire from a main panel to the ground rod.So I got to wondering, what does THAT ground do? All grounds from fixtures and devices end up back at the main panel, where they tie into the POCO's neutral. So what is the ground wire to ground rod doing?The only thing I've been able to think of, is if the POCU neutral line got knocked down, while the hot lines remained, then there is alternate return to ground. But maybe there is something else.
Most importantly,the panel's ground wire provides a short path to ground for lightning strikes to the entry cable. Beyond that, the POCO's pole transformer is grounded by the net combination of all the grounds at all the service entrances, creating a much better, truer ground than would be the case if it were just grounded at the pole. And, as you said, the ground assures that the system remains grounded should the POCO neutral connection be broken (a fairly common problem, actually -- "open neutral" on a 240V line).There are probably a half-dozen other reasons I'm not thinking of.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin