Ground issue

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Oakey

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New Jersey
I am replacing a small vent fan in an attic. I noticed that there was only 25 volts to ground and that there is 120v to neutral.This indicates to me an open ground. I cannot find where this break is so I am recommending a gfi breaker in then panel. Am I correct in this diagnosis and action? Thx
 
Take these measurements and what do you have:

Line to EGC
Line to Neutral
Neutral to EGC

Your 25 volt to ground doesn't tell me squat, like between what two points did you obesrve 25 volts.
 
Installing GFCI on this is like putting a Bandaid on a bullet wound. It is better than nothing, but does not repair the defect. GFCI is not a substitute for proper grounding/bonding. If there is no equipment ground available in the wiring method, we are allowed to use GFCI to protect replacement receptacles (and only replacement receptacles) as a last resort. If this circuit had a bad neutral wire, would you replace it with the equipment grounding conductor? Repair or replace the wiring and forget about GFCI.
 
There are no options. You must install new circuit or find a way to repair the old circuit. Very seldom do wires just break within a wall. You will probably find a junction with a bad splice somewhere.
 
I would also measure Line-Neutral and Line-Ground back at the panel (or the source of the branch circuit) just to verify the problem is in the branch circuit.

Steve
 
My correction
Hot to neutral-120v
Hot to ground -43 v
Ground to Neutral-23v



Edited due to stupidity..
 
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Assuming that John's question is correct, I'd say it's time for a different source of power, and perhaps checking to see if anything else reads funny.
 
JohnJ0906 said:
Is the bottom one supposed to be "Neutral to ground"? :confused:
Doh! Ok one cold one coming your way...
drink.gif
 
Oakey:

You wouldn't happen to be using a high impedance type tester/meter would you? If you are you might be seeing stray/ghost voltage because your grounding wire is open.

I just ran into that using a tester and DMM also. Plugged in a stray voltage adapter and the voltage was gone!
 
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