GFCI Troubles PLEASE HELP

I wired my basement for a workshop. I have 12 outlets around the room. Every other outlet is on a different circut, there are three circuits. 1) Black 2) Blue 3) Red and one neutral 4) white. The first three outlets are GFCI outlets. Black goes through the first one, Blue through the second one, and Red through the third one, they all use the same neutral. After that the outlets are standard and their all wired in parallel. If I power up one circuit it works flawlessly, but as soon as I power up a second circuit, one of the GFCI's trip, usually black if its powered up, but both the red and the blue GFCI have tripped. Is this because they all use the same neutral? Or am I going to have to pull the wires out of the conduit and look for a short? I have gone over all the boxes and they are all wired correctly, color to gold and white to silver. Also, all my wire nuts are secure and there seems to be no marred or damaged insulation. I was super carefull, so I don't really think there is any damage even deep within the conduit.

Any help would be great.
Chuck

 

Stop!!

There are at least two problems here.

First, and most important, is that you cannot use one neutral wire for three circuits. This is dangerous beyond your wildest dreams.

Second, you cannot get downstream GFCI protection on any circuit that uses a shared neutral. If you do share a neutral, then you must install a GFCI receptacle in every outlet, not just the first.

I suggest you simply pull two more neutral wires (marking them carefully so that you know which neutral goes with which hot). This will solve both problems.

 

thanks John... I was afraid that might be the case. So in no case should I run multiple circuits on the same neutral right? I figured that. I'll pull two more neutrals, maybe a red stripe and a blue stripe if I can find them.

Chuck

 

I didn't say that there were no cases in which you could share a neutral. I just said that your case isn't one of them.

The details are complicated, and the risks are significant for someone who doesn't understand all of the rules. I suggest you just forget about sharing neutrals.

 

John,, I think you mean pull 2 new neutrals from the panel correct? Why would you have to mark them?

 

The only reason to mark them is so that you install the correct neutral with the correct hot. Otherwise, you again risk overloading the neutral, and you will trip the GFCI if you mess it up.

And yes, as you say sberry, the new neutrals must go all the way back to the panel.

 

Just out of curiosity John,,,, he is using gfci recepts,, what do you mean correct neutral with hot,, neutral is common,, if there is more than one white wire coming out of the pipe you still put them the same place.

 

Maybe I been sniffing too many paint fumes this afternoon and am missing something.

 

The neutral carries the return current from the hot. You want to make sure that each neutral is carrying exactly as much current as the hot it is paired with. This is necessary both to avoid overloading a neutral and to keep the GFCI from tripping.

It is not a good idea to think of a neutral as a "common". It is important when connecting a hot wire to a receptacle to connect the neutral wire that it is paired with, and no other.

 

From the gfci back to the panel it wouldnt matter which was which,,, On the load side of the gfci it would and you would need to pair them. Maybe we not stuck on same page.

 

sberry, if it didnt matter what nuetral went where, then why dont we just have one white wire #12 for example coming out of the panel and loop it to every outlet and recepticle in the house?
curious.

 

Gentle men: It appears to me that you do not understand how to properly connect a GFCI. First of all sharing neutrals is fobidden. The neutral wire that comes back to the panelfrom from a receptacle must connect to the circuit breaker from which its power came from.Then the currely white wire on the breaker will go to the neutral bar. Buy installing the neutral from the receptacle into the breaker it can now do the job it was intended for (compare hot to neutral currents) If you install additional receptacles down stream from this then they will enjoy ground fault You may have had the neutrals crossed which caused the breaker to trip as should. Please feel free to email me if any further clarification is reqyured
Jafro

 

Hey,,, he said he is using gfi recepts,,, not gfci breakers!

 

I didnt read anywhere in his post that he had gfci breakers,,, did I miss that,, he said recepts did he not?

 

You are Righjt SBERR27about the receptacle . The fact still remains that his neutrals are mixed up

 

Jafro, it appears to me that you dont know how to read a post and correctly troubleshoot it. like sberry27 said we are talking about gfic recept. There are gfic breakers that go in the panel, but no one is talking about them in this particular thread. So before we get Chaz all confused, and tell him to run nuetral wires to the breaker, lets get the story straight.
And gee it is so nice of you to offer your e-mail address to help all of us here, but remember this is a community forum, so people can post here and help everyone.

 

Ok,, now everyone is on same page,, the home runs dont need to be identified,, the load side pair does need to be matched.

 

Sberry, if you have more than one multiwire branch circuit coming from different branch circuits coming out of that conduit. Then if you connect the white wires serving as neutral conductors of those different multiwire branch circuits all together where they come out of that conduit wouldn't you be paralleling neutral conductors smaller than 2 awg from the panel to that junction box?

If you are paralleling conductors smaller than 2 awg then you would be in violation of the Code, wouldn't you?

Curious

Wg

 

There is no multi wire branch circuit when he does it correctly. That was the original problem. He needed to pull 2 new neutral wires back to the panel and new neutrals from the gfci devices to the recepts. Those would need to be paired. The neutrals going back to the panel do not need to be identified,,, they go to the buss. My original point was that he needed worry about which white went where on the line side of the gfi,,, only after. This whole thread got mis- read by everyone from the start and I added to the confusion I guess. I never advocated connecting whites together there. or anywhere. Each gfci needs its own but you dont need to concern with which one is to which gfci on line side,,, just so that it runs to the panel.

 

sberry, your right I must have misread your intent in your previous reply. I thought you were saying to connect all white wires in a box whether from same branch circuit or not together. This was what concerned me. You were saying what you meant, I just misread what you said.

Sorry

Wg