13 posts / 0 new
Last post
canuk
Re: GCFI instalation problem
rpeirce wrote:

I have a 200 amp gould electrical panel. I am installing a 20 line with NM 12/2 wire in my basement for 9 electric plugs in my workshop. Current city code requires a gfci circuit in basements. I tried first a siemans gfci breaker then a square D breaker. Both trip- the siemans immediately and the square D in about 10 to 15 seconds, even if the circuit wire is disconnected from everything at the first junction box. The polarity on all plugs has been checked and I have checked that there are no grounds in the system (between the white and black wires). The junction boxes and outlets are grounded with the ground wire in the cable which is attached to the ground bus in the main box. When I install a regular (non GFCI) 20 amp breaker in the circuit, everything works fine.
The main breaker box has a number of circuits, since it supplies all the circuits in the house (furnaces, washer/dryer, etc.) I am stumped, since even when the wire for my new circuit is completely disconnected from everything at the first junction box, the GFCI still trips. There are no other GFCI breakers in the main panel.

Interesting the Square D is slower to trip -- perhaps that breaker has a longer duration timing .

Yes the the pigtail from the GFCI breaker should be connected to the neutral bus directly.

Considering a regular breaker doesn't trip indicates there is no phase to grounding short or phase to neutral.
However , I'm curious if the grounding conductor inside the box is touching the neutral screw of the first receptacle. Or -- when you stripped the cable jacket you may have knicked the neutral covering and it's in contact with the bare grounding conductor.

canuk
Re: GCFI instalation problem
The Semi-Retired Electric wrote:

Actually, the coiled white wire from the GFCI should be attached to the Neutral bus not the ground. It may not matter in the main panel where the neutral and ground bus are electrically the same point. But, in any panel after the first disconnect (or OCP), they are isolated from each other.

Ditto Houston, about the wire.

Does the GFCI trip with both the load white and black wires removed?

When resolved, only the GFCI recommended by the Mfg. should be used.

Good Luck from Columbiana, Alabama
Maurice Turgeon, http://thesemi-retiredelectrician.com

That's a concept that can really make heads spin.
-- the grounded ( neutral ) is a normally current carrying conductor whereas the grounding conductor is not ( except when there is a ground fault or leakage current ).
When you think about it --- they are only at the same potential but actually electrically different in fuction.

Pages

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.