I have a trouble-shooting question concerning a GFCI.
I am an electrician, and a buddy called me tonight and was having trouble with a GFCI that he had just installed in his house.
Details:
The existing circuit had a normal outlet and he wanted to install a GFCI.
The normal outlet worked fine.
The Branch Circuit to the outlet was a 12/2 romex
The branch Circuit was fed with a tandem 20-amp breaker.
The breaker had the correct voltage at the termination point.
He took out the standard recep and installed the GFCI.
When he flipped the breaker back on, the GFCI would not stay set. I guess it would never set at all.. Every time he would try to push the reset in it would not hold.
He tried a few other GFCI?s and they would not set either.
He then called me.
I told him to start with the basics. Unhook the 12/2 wires completely from all lugs in the panel. (Breaker,Neutral bar, groundbar) Fan out the your same conductors at the outlet box.
Do a continuity test between all the conductors with nothing tied between.
All conductors were open just as expected on a good circuit I guess.
I then had him verify he had the correct wires. He made a current loop with all wires. Hot and neutral tied together and then a continuity test. All wire combinations checked out. (He had continuity through the circuit)
This is where we are tonight.
I told him to take a short piece of romex and make a small branch circuit right at the panel. Hook up the GFCI. This thought process was just to see if you eliminate the existing field pulled romex maybe the GFCI would reset. If it would not reset at the panel, well, then I really don?t understand! Kind of grasping at straws but it seemed like a good test to maybe get my thinking heading in the right direction.
I also told him to hook up the branch circuit to another breaker and not the Tandem. I have thought about this, and cant see a problem with the breaker set up. Essentially it?s just a parallel point.
I honestly can?t see any problem with any of it. The solid state CT circuitry in the GFCI is just monitoring between the hot conductor and the grounded hot conductor and the only way the GFCI would trip is if there is a shunt going to ground or out another source. I guess the device is hanging in mid air at the outlet and is not touching anything.
Anyhow, I am stumped and have been thinking about it all night. I will probably go over to his house and do some tests myself tomorrow, but I thought I would pose the question. Heck, maybe I am totally forgetting about something. I can see if he couldn?t get it to trip out with a tester or something, as the tester shunts to ground and maybe the ground is bad, but not work at all?? Maybe three bad, new GFCI's?
Thanks for any advice. I will keep all posted if this is just not a no brainer on my part and I am being an idiot.
I am an electrician, and a buddy called me tonight and was having trouble with a GFCI that he had just installed in his house.
Details:
The existing circuit had a normal outlet and he wanted to install a GFCI.
The normal outlet worked fine.
The Branch Circuit to the outlet was a 12/2 romex
The branch Circuit was fed with a tandem 20-amp breaker.
The breaker had the correct voltage at the termination point.
He took out the standard recep and installed the GFCI.
When he flipped the breaker back on, the GFCI would not stay set. I guess it would never set at all.. Every time he would try to push the reset in it would not hold.
He tried a few other GFCI?s and they would not set either.
He then called me.
I told him to start with the basics. Unhook the 12/2 wires completely from all lugs in the panel. (Breaker,Neutral bar, groundbar) Fan out the your same conductors at the outlet box.
Do a continuity test between all the conductors with nothing tied between.
All conductors were open just as expected on a good circuit I guess.
I then had him verify he had the correct wires. He made a current loop with all wires. Hot and neutral tied together and then a continuity test. All wire combinations checked out. (He had continuity through the circuit)
This is where we are tonight.
I told him to take a short piece of romex and make a small branch circuit right at the panel. Hook up the GFCI. This thought process was just to see if you eliminate the existing field pulled romex maybe the GFCI would reset. If it would not reset at the panel, well, then I really don?t understand! Kind of grasping at straws but it seemed like a good test to maybe get my thinking heading in the right direction.
I also told him to hook up the branch circuit to another breaker and not the Tandem. I have thought about this, and cant see a problem with the breaker set up. Essentially it?s just a parallel point.
I honestly can?t see any problem with any of it. The solid state CT circuitry in the GFCI is just monitoring between the hot conductor and the grounded hot conductor and the only way the GFCI would trip is if there is a shunt going to ground or out another source. I guess the device is hanging in mid air at the outlet and is not touching anything.
Anyhow, I am stumped and have been thinking about it all night. I will probably go over to his house and do some tests myself tomorrow, but I thought I would pose the question. Heck, maybe I am totally forgetting about something. I can see if he couldn?t get it to trip out with a tester or something, as the tester shunts to ground and maybe the ground is bad, but not work at all?? Maybe three bad, new GFCI's?
Thanks for any advice. I will keep all posted if this is just not a no brainer on my part and I am being an idiot.