Lights kitchen ground fault

kevin1564

Member
Im wiring a residential home. There are two breakers 11 is feeding the lights and 7 is feeding plugs. With 7 on and hot wire tied in with the other hots from circuit 11 on of the hot wires gets 100 volt to ground From both the hot and neutral but 0 volts from hot to neutral. When close the path to the lights with the circuit to the lights off. The voltage to ground on the romex in question is getting 40 volts. With just the circuit to the lights on the romex in question gets 0 volts to ground. It sounds like they have a ground fault somewhere that’s not tripping possibly from being tied to the neutral or the egc is not connected to the panel? I’m looking for suggestions on likely solutions to the issue.

kevin1564

Member
The romex is isolated when I’m testing voltage.

don_resqcapt19

Moderator
Staff member
Exactly what device are you using to measure the voltage?

kevin1564

Member
I’m using a high impedance tester I put a light trim on the hot and ground on the same romex and it dropped to 26 volts but not to zero and the light did come on.

Open EGC?

kevin1564

Member
I’m getting 120 volt to ground with the hot for circuit 11 closed.

kevin1564

Member
I’m not on sight but Ill draw a map of the circuits asap.

Ponchik

Senior Member
First, Why is circuit 7 connecting to circuit 11?

Second, connect a incandescent load then check for voltage. You may be reading ghost/phantom voltage.

kevin1564

Member
First, Why is circuit 7 connecting to circuit 11?

Second, connect an incandescent load then check for voltage. You may be reading ghost/phantom voltage.
I put an LED light trim on the hot and ground wire the voltage dropped from 90 volt to 26 but the light did come on. Does it need to be an incandescent light?

kevin1564

Member
I put an LED light trim on the hot and ground wire the voltage dropped from 90 volt to 26 but the light did come on. Does it need to be an incandescent light?
I put an LED light trim on the hot and ground wire the voltage dropped from 90 volt to 26 but the light did come on. Does it need to be an incandescent light?
At this point I’m coming to the conclusion that there are joints in the attic or the walls between 7 which if for the living room and 11 which is feeding the living and kitchen lights. That’s back feeding a neutral through the ground.

ptonsparky

Senior Member
Get a low impedance meter or a solenoid type tester.

LEDs are not a good tester, as you have found.
You would be better off using a homemade set of test lights and that's not a recommended practice.

Little Bill

Moderator
Staff member
I put an LED light trim on the hot and ground wire the voltage dropped from 90 volt to 26 but the light did come on. Does it need to be an incandescent light?
Often times, an LED is not enough load for a dimmer to operate correctly. So it probably isn't enough load to kill ghost voltage. I would get a pigtail socket with a regular (incandescent) bulb for testing. Unless you have a low z meter.

kevin1564

Member
Often times, an LED is not enough load for a dimmer to operate correctly. So it probably isn't enough load to kill ghost voltage. I would get a pigtail socket with a regular (incandescent) bulb for testing. Unless you have a low z meter.
I have a low impedance solenoid tester I’ll try that. Thanks!