# electrical-using a 2 pole breaker for 120v circuit



## Speedy Petey (Feb 1, 2004)

I have absolutely NO idea what you are asking. The way you explain things it's as if we already are familiar with the situation.

To answer a question; Yes, you can use one side of a two-pole breaker for a 120v circuit.


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## a7ecorsair (Jun 1, 2010)

You cannot have 240 volts unless the inverter output is 240 volts. It would also have to provide a neutral. Is this setup completely off grid?
So to start with, what is the output specification of your inverter?


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## joed (Mar 13, 2005)

How are the neutral and ground connected/bonded? Are they connected?

Those plugin testor in siplified terms measure hot-neutral, hot-ground, neutral-ground. It must be getting a reading of voltage neutral ground to give a hot neutral reverse.


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## AllanJ (Nov 24, 2007)

For a system completely off grid (no connection to a public utility) nothing prevents you from connecting one 120 volt hot feed line to both hot feed lugs of a panel. But you may not have any branch circuits in which there are two hot wires (say red and black) and one neutral wire.


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## mreed (Sep 29, 2011)

*electrical-using a 2 pole breaker for a 120V circuit*

Sorry to speedy for not being clearer. Now, the inverter does only put out 120 volts, so that certainly makes sense. My setup is completely off grid.
My main panel has power coming in from the panels through a charge controller to the batteries, to the inverter, into the main panel. It also is set up to use a generator when necessary. 
I have two houses going off the main power panel. I have a 2 pole 50 amp breaker which I have the hot in one side of the breaker and the neutral in the other and ground on the bus bar. This is AWG12 wire, 3, one hot, one neutral and one ground. So, my question is, can I put one hot wire in each of the poles, put the neutrals on the bus bar and use a grounding bar for the grounds? Will this solve the problem of neutral to ground having voltage, which yes, it is showing on the main panel.


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## mpoulton (Jul 23, 2009)

mreed said:


> Sorry to speedy for not being clearer. Now, the inverter does only put out 120 volts, so that certainly makes sense. My setup is completely off grid.
> My main panel has power coming in from the panels through a charge controller to the batteries, to the inverter, into the main panel. It also is set up to use a generator when necessary.
> I have two houses going off the main power panel. I have a 2 pole 50 amp breaker which I have the hot in one side of the breaker and the neutral in the other and ground on the bus bar. This is AWG12 wire, 3, one hot, one neutral and one ground. So, my question is, can I put one hot wire in each of the poles, put the neutrals on the bus bar and use a grounding bar for the grounds? Will this solve the problem of neutral to ground having voltage, which yes, it is showing on the main panel.


You need to connect the inverter's hot output to BOTH of the hot busses in the panel, and neutral needs to be connected to the neutral bar and bonded to ground. You can either use a double pole breaker with the hot from the inverter connected to BOTH poles, or you can just connect the inverter's hot directly to both of the panel's main lugs without using a breaker. Most inverters have internal overload protection so there is no need for a circuit breaker on the inverter's feed to the panel.


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## mreed (Sep 29, 2011)

Thanks for the info, I appreciate your input. I talked to an electrician friend of my sons and I'll do that. This is a high tech inverter and it requires a main breaker panel before the sub panel. All is well:thumbup:


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## mpoulton (Jul 23, 2009)

mreed said:


> Thanks for the info, I appreciate your input. I talked to an electrician friend of my sons and I'll do that. This is a high tech inverter and it requires a main breaker panel before the sub panel. All is well:thumbup:


What do you mean by that? How can the inverter require a subpanel of the entire system is off-grid? Something doesn't add up here...


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## mreed (Sep 29, 2011)

Sorry, I guess being a 'newbie' I am not explaining myself very well. What I mean is, the inverter is the power that goes to a load center bringing the power in and then on to the sub panel that powers my house. I am actually still at a loss with my system.

From the inverter to the load center that takes the power to the house, I am still having a neutral to ground voltage. I tested the inverter and it is perfectly normal..1.5V, then the inverter puts the power into the 50 amp breaker box (required by Trace) and then to the house circuits. If I shut everything down except the power from the inverter to the 50 amp breaker box, I read 120V from neutral to ground which continues through the whole system once turned back on. If I test the receptacles, they read normal, all wires in both load centers are correct...I'm at a loss!!


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## a7ecorsair (Jun 1, 2010)

Deleted, missed one of the OP's replies...


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## mreed (Sep 29, 2011)

The inverter is a 4024 (4000 watts, 24 volts dc system) and it is a 120V. It is a Trace inverter.


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## a7ecorsair (Jun 1, 2010)

mreed said:


> *I have a 2 pole 50 amp breaker which I have the hot in one side of the breaker and the neutral in the other* and ground on the bus bar.


This is your problem.
Disconnect the neutral from the main breaker and connect it to your neutral bar.
Use a piece of wire and make a jumper to connect the two Line side terminals of this 50 amp two pole breaker together. Use wire the same size at the feed from the inverter.


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## a7ecorsair (Jun 1, 2010)

Some more questions for the OP
Does the sub panel have two bus bars?
You say there are only 4 circuits, so does the sub panel have room so all four breakers can be on one bus bar?
If so, you would only need to use one side of the 50 amp main.


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## mreed (Sep 29, 2011)

Thanks for all of your good input! I rewired my 50amp breaker which actually had the two hot wires together as I'm going to 2 houses and jumped the poles, using both hots, put the neutrals on the bus bar and the grounds on a grounding bar...power is fine...as in everything works, but it is still showing neutral-ground voltage. I had tried bonding the neutral and ground, but not good with my inverter, so changed it back to the grounding bar. As to the sub panel, it has 2 double 20 amp breakers for my house and all neutrals are on a single bus bar and grounds are on a grounding bar. Both the main and sub panel register neutral to ground voltage...119-121V. None of my receptacles show neutral to ground voltage so no reversal, but they all say there is a reversed hot/neutral with a plug in tester.


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## mreed (Sep 29, 2011)

The problem is, everything has worked fine for years. I redid a lot of wiring last year and put in GFCI's and I've never had an electrical problem. The other day, I was using a circular saw with a cord that my bro had cut in half and didn't notice it had come loose and power went down. It was on a GFCI and didn't trip but my fuse on my batteries to the inverter blew and the 50 amp breaker. I replaced them and all was again fine, although I don't really know what happened. I had just gotten a new really cool digital meter with all the bells and whistles and a GFCI plug in tester. When I plugged the plug-in in, it showed hot/neutral reversal all over the place....which I said was nuts, so I started testing all of the plugs in my house and found that there was no more than normal voltage between neutral and ground meaning no reversal. That is when I tested the main panel and it had voltage neutral to ground, as does the sub panel. When I turned off the sub-panel, I still had the voltage neutral to ground in the main panel, but the inverter has none.....it is 1.5V exactly from neutral to ground...I'm lost!


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## mpoulton (Jul 23, 2009)

Your description of this system is still not making sense. I read the inverter manual, and I'm quite familiar with both off-grid and grid-tie solar power systems. Why do you have two panels if this is an off-grid system? The only mention of main/sub panels in the inverter manual is for grid-tie or generator synchronized installations. Exactly how are the two panels wired? Specifically, how does the inverter feed the first panel, and how does that panel feed the sub? I'm assuming that's how you have it set up, since it wouldn't make sense for the main panel to feed the utility input to the inverter like the manual describes, if there is no utility power. What loads are in each panel? Is there any neutral-ground bond anywhere?

I'm going to go out on a limb and suggest that the inverter probably had an internal neutral-ground bond, and it burned when your saw shorted. Now the inverter output is floating. It's a total mystery why you're reading 120V from neutral to ground in some places and not others - that sounds like the result of multiple wiring errors, but there's no way to tell without a much better, more detailed description of your wiring. Or pictures. Pictures would be great.


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## a7ecorsair (Jun 1, 2010)

4024 Inverter

Your inverter has only two output connections AC Hot and AC Neutral and the output is protected by 60 amp fuse.
This output should be connect to your sub panel with at least #6 Copper wire. There is no need for any other breakers.
I would mount the inverter so it is isolated from any earth contact.
At your sub panel connect all your neutrals and grounds on the same bar.


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## mreed (Sep 29, 2011)

I'm thinking that 'out on a limb' may be an answer...In answer to your other questions....AC hot out and AC neutral out go into a load center box with a 50 amp 2 pole breaker from the inverter(rather than a fuse, probably should be 60, but didn't have one handy after the saw thing).
They are wired into the top of the breaker taking power into that breaker. Coming out of the bottom of the breaker, one side goes to my house and one side (2 pole breaker) goes to my sons house. His is plugged into a GFCI powered by the inverter through the 50 amp breaker. The other line runs to my house to a sub panel with 4 20 amp circuits.
The generator has its own breaker, plug from generator going into breaker and out to AC1 hot and neutral on the inverter. This system was set up for many years...as in 30 and last year finally got an entire solar set up. All wiring is done properly and it has functioned perfectly for 30 years and for the last year when I added 9 panels and a solar rack. There is #6 wire going from the inverter AC hot and neutral and ground to the breaker. The breaker is because where the power goes out from the inverter with #6 needed to be a short distance, then using #12 to the house and sub-panel.

I think that the inverter does have a bonded neutral and ground and the other day, I thought I'd try setting up the breaker by bonding the neutral and ground and the inverter definitely didn't like it, it went to error immediately. I redid it with the grounds on a grounding bar and all was fine again.

There is a fuse coming from the battery bank to the inverter as a disconnect (which blew the other day), there is also a disconnect on my charge controller.

I have come to think that it has something to do with the inverter to the breaker, as when I turned off the sub panel, the breaker reads the voltage between neutral and ground, but the neutral to ground in the inverter reads 1.5V as it should.


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## mreed (Sep 29, 2011)

Oh, the inverter is mounted on a wall. I have a solar shed. I thought sub-panels weren't supposed to have bonded neutral and ground? The inverter, batteries etc. are all grounded to a copper grounding rod. The inverter has 2 grounds, one going to the rod and one going out to the breaker.


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## Techy (Mar 16, 2011)

neutral from the inverter should not go to a breaker, it should go to the neutral bar in the sub panel


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## mreed (Sep 29, 2011)

Can I connect the neutral from the inverter to the line going to the house subpanel or do I have to run the #6 the whole distance?


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## mreed (Sep 29, 2011)

By the way, a7ecorsair, great picture!!


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## a7ecorsair (Jun 1, 2010)

mreed said:


> Oh, the inverter is mounted on a wall. I have a solar shed. I thought sub-panels weren't supposed to have bonded neutral and ground? The inverter, batteries etc. are all grounded to a copper grounding rod. The inverter has 2 grounds, one going to the rod and one going out to the breaker.


Sub panels, when installed according to NEC guidelines also require a 4 wire feed, two hots, a neutral, and a ground.
If you want to follow this, you have one hot and one neutral going to your sub panel.
Since you have a main breaker box that is grounded, bring a hot, a neutral and a insulated ground to your sub panel.
At your main breaker box you will have to connect (bond) the neutral and ground together on the same bar or lug.


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## a7ecorsair (Jun 1, 2010)

mreed said:


> Can I connect the neutral from the inverter to the line going to the house subpanel or do I have to run the #6 the whole distance?


Yes, you will need a #6 for the hot, a #6 for the neutral, and probably a #10 for the ground.


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## mpoulton (Jul 23, 2009)

Need pics at this point. I keep trying to get an EXACT description of how your system is wired, but your descriptions are anything but exact. You make it sound like you fed the hot and neutral from the inverter through separate poles of a 2-pole breaker in a panel with nothing in it except that one breaker, and then sent the hot by itself to feed your house, and the neutral by itself to feed your son's house. Nothing about that is right and I'm positive that's not actually how it's wired, because it never would have worked. I'd have to see pics of all the wiring to figure this out.


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## mreed (Sep 29, 2011)

Sorry but I don't know how to do the pic thing. My manual is very old and I just saw the '2nd' version today. Your right, that wouldn't have worked and no it isn't wired that way. The problem gets weirder however. 

1. From ac hot output on the inverter, both poles are to the hot of both houses black wire in one pole for my house, black wire in other pole for other house, poles jumped.
2. From neutral out, both white wires to the houses are connected with the ac neutral out. 
3. Both grounds are connected on a grounding bar. I disconnected one of the ones on the inverter and left the earth ground on.

I was still getting voltage (120V) from neutral to ground, in inverter as well as panel. I thought I'd try bonding the neutral and ground because I read that the trace 4024 doesn't have a neutral-ground internal bonding (which I thought it did) and the inverter went to 'overcurrent' error immediately...put the grounds back on the grounding bar.

Tomorrow, I am going to change it to a 60 amp fuse and run #6 straight from the inverter to the sub-panel. The sub-panel has a bus bar for neutral and grounding bar for ground and I don't know if that will be a problem, but at this point I'm brain dead. It seems to have something to do with the neutral and grounding and info on grounding and neutral in this inverter seems hard to come by. I've had this inverter for alot of years and it's always been great. The short with the saw is the first time I've had a problem and it blew out the fuse from the battery and the breaker and it was plugged into a gfci, so I can't figure that out at all.

And with all of this, the power and inverter seem to be working perfectly, but I can't help thinking that it could do something weird again because I've messed something up somewhere.


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## a7ecorsair (Jun 1, 2010)

I've attached another picture showing the manufactures diagram with grounds highlighted. Notice all the grounds go to the main panel. In this main panel the building wiring would have all the neutral and ground wires connected to the same bus bar. Then the sub panel that supported by either the the main or the inverter, has a ground wire back to the main. This main panel would be earth grounded.
You are not connected to the grid and you do not have a sub panel it is just a panel.
*Do not ground your inverter other than through your panel.*
The output of your inverter should be *protected by one 50 amp breaker*.
Do not use both sides of the two pole breaker for hot feeds, take your two taps from the bottom of one side of the breaker.
Your panel will need a ground rod.
You will connect your tap from the bottom of the 50 amp breaker to your panel breaker bus.
You will connect the AC neutral from the inverter which can pass through along side your breaker to your panel or you can use the other side of the 50 amp breaker to pass the neutral. Turning the breaker off would disconnect both the hot and neutral.
You will need a #10 ground wire from the inverter AC ground to your panel.
Now, in your panel, all ground and neutral wires will be connected to the same bus bar.

Does your son's house have a panel?


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## mreed (Sep 29, 2011)

Thank you for taking all this time and the picture is great. I want to be sure I'm understanding what your saying. 

1st, I always had the 50 amp breaker set up with one pole hot and one pole neutral and a ground from the inverter into the breaker box. Then the #12 ran straight to the house. Through all the discussion about the 2 pole breaker, I changed it, putting one hot in each side and the neutrals separate, as well as the grounds. My sons house was tied in with mine to the bottom of the breaker and goes to a gfci and we just plug in his house, no panel. The inverter has been earth grounded since I put in the new solar system, they wanted everything grounded, batteries, solar rack, charge controller....

Just so I'm sure that you understand that I don't actually have a main panel as in the picture, but where they show the 60 amp fuse for hot output is where I have my breaker. 

So, if I put my breaker back the way I have always had it(hots in one pole, neutral in the other, grounds on bus bar) and undo the one earth ground on the inverter and ground the inverter to the breaker, I would earth ground that box before going into my house panel? Then in my house panel, I would bond the neutral and ground on one bar?

I'm a little nervous about bonding the neutral-ground because of the immediate error of 'overcurrent' light that came on the inverter when I tried that with the box with the breaker. 

I have the feeling that you are right and that the earth ground on the inverter is causing all the problems, I have been racking my brain for the last 3 days and think I'm becoming paranoid!


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## mreed (Sep 29, 2011)

One other thing, where they show the ac ground in the picture is where I have it grounded to earth. On the other side where the outputs, inputs etc. are is another bolt on the side of the inverter where we have always run the ground to the breaker.


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## a7ecorsair (Jun 1, 2010)

mreed said:


> One other thing, where they show the ac ground in the picture is where I have it grounded to earth. On the other side where the outputs, inputs etc. are is another bolt on the side of the inverter where we have always run the *ground to the breaker*.


It is hard for use to visualize what you have and terminolgy is sometimes a problem too. Like above, breakers don't have grounds but maybe the panel it is mounted in does.
You can leave the AC Ground connection at the inverter if you like but be sure your panel is also grounded and run your AC ground to the panel from the AC ground on the inverter.


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## mpoulton (Jul 23, 2009)

mreed said:


> One other thing, where they show the ac ground in the picture is where I have it grounded to earth. On the other side where the outputs, inputs etc. are is another bolt on the side of the inverter where we have always run the ground to the breaker.


I can't visualize any of this. You don't run a ground wire to a breaker, and I doubt that you actually did. Pictures aren't hard. You just use the "manage attachments" button down below the reply window in the "additional options" section when you're typing a reply post.


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## mreed (Sep 29, 2011)

I went from my breaker to a main panel box, bonded the neutral and ground and took the earth ground off of the inverter. Wah-la, everything is testing perfect! I am just putting the earth ground on the panel box, but I am happy to say that I have no more voltage between neutral and ground and everything inside and out is testing perfect. Thank you for all of your help!! I also moved my son's house to the main panel.


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## a7ecorsair (Jun 1, 2010)

Nice to hear it worked out:thumbup:


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