Hello folks,
Hope someone can explain this. I have basically completed wiring my new home. It's still in the rough so I wanted to test some circuits. I have no power from the street yet. I do have temporary power hooked to my job site separately. Do have a GFCI receptacle hooked to the temp power. So to test my first circuit I used a known good extension cord and plugged in the bare hot and neutral on one of the homeruns and the circuit tested good. So then I thought I would connect the neutral from that same circuit to the several panel neutral bar and then apply my temp power neutral to the neutral bar and apply the temp power hot leg to the circuit. Every time I try this it trips the GFCI. I do not have the ground from the circuit connected but it was also not connected when I tested the same circuit without hooking to the neutral bar. Maybe there is something I didn't ne unde stand. Any help I am all ears. Thanks. Jim

 

I see what you're doing but don't understand why.
You aren't really checking anything like that.

What GFI is tripping..... something on the generator ?

 

Is the bonding screw installed in your panel. If so it is bonding neutral to ground and the gfci should trip.

 

GFCI's don't need a ground to trip. They detect a differentiation between the hot and neutral. Curious, too what gfci he is referring to. Possibly the one in the temporary panel.

 

Ok.... somehow I read generator instead of temp power.

Your ground/neutral bus bar IS grounded causing the GFI on your temp power board to trip.
When you connect the white coming from the temp power.... that is like connecting that white to ground. The neutral/white wire after GFI protection cannot touch ground.

 

If in a temp box,(load side) that is correct. From a main power source it would not trip.
I have the same question as Pete. Why are you testing it like this?

 

Back to answering his question.
He can try temporarily removing the bonding screw. Then he should test for an absence of ground to neutral continuity -- i.e. he doesn't want to have any, with a low voltage continuity tester.

His purpose seems to be to use the temp power as a 110V continuity tester. He should probably try a low voltage tester first, if he hasn't already done so. Beyond that, he may be wanting to test some of his circuits for open connections, switch logic, etc. Notable is that with a 110 volt connection from temp power, he will only be able to test one leg of the panel at a time. If he had a 220 cord, he could test both legs simultaneously. Don't know if AHJ would like either type of test.

 

Sonofprim in the U.S. nominal residential voltages are 120v and 240v. You are very helpful with your posts but please remember to use the correct voltages.