can you test a GFCI outlet wth a volt meter?

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Old 03-17-18, 05:17 PM
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can you test a GFCI outlet wth a volt meter?

old house, half of the house is old style BX, (the kind with the insulation that falls off when you touch it and doesn't have the ground wire) two prong non grounded outlets.
other half was upgraded n the 1960's with a breaker panel and the more modern BX. this half has three prong grounded outlets.

one of the old circuits tripped the breaker, would not reset.
since i knew from experience, any wire i touched on the old BX while lookng for the short would just cause the insulation to fall off and cause more shorts, i am replacing all of the old BX and two prong outlets with ROMEX and three prong outlets.
i am dong it one outlet at a time, testing, then move on. in case i do something wrong it will be a lot easier to find it.

the problem.
first outlet i put in is a GFCI.
the romex going from the GFCI to the next out was left disconnected. ends of wires were not touching.
reset breaker, light on GFCI comes on.
put volt meter probes in GFCI, GFCI trips.
tried testing at the disconnected end of the romex, tripped. disconnected end is where the next outlet goes.
is this normal?
does the GFCI read the volt meter as a ground fault?
or is it having a problem because the next outlet is not connected?
or did i do something backwards?
 
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Old 03-17-18, 05:27 PM
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does the GFCI read the volt meter as a ground fault? No.
or is it having a problem because the next outlet is not connected? No.
or did i do something backwards? possibly.

Testing across the two slots of a GFI receptacle will not trip it. A GFI reads an inbalance between the slots which usually signifies a short or leakage to ground. The supply wires should be connected to the LINE side of the GFI. Remove the load wires and test it again.

 
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Old 03-17-18, 08:24 PM
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just disconnected the load wires.
several tests with the volt meter on the line terminals or black and ground wire showed 120VAC.
then i tried the slots, and when i went from black to ground, it tripped.
went back to black terminal and ground wire and it tripped.
could it be a defective GFCI outlet?
 
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Old 03-17-18, 08:25 PM
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I have found that GFCIs will trip if you take a meter and test from hot to ground or neutral to ground because the meter is allowing a path to ground causing ground fault.
 
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Old 03-17-18, 08:46 PM
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first test, with the load wire connected, it was tripping with the tester in the hot and neutral slot and when i put the tester on the hot and neutral on the other end of the load wire, where the next outlet is going.
 
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Old 03-17-18, 09:03 PM
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Old 03-17-18, 09:33 PM
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Originally Posted by XSleeper View Post
i have one of the non -GFCI testers. same as that one, but cant test GFCI's. dont think GFCI's were in use when i bought that one.
are you saying the easiest thing for me to do is plug one of those GFCI testers in?
 
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Old 03-17-18, 09:36 PM
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That's the first thing I would do.
 
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Old 03-17-18, 10:46 PM
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Are you sure these are straight GFI receptacles and not ones with some kind of arc fault protection ?

I have never had a GFI trip when plugging in any test meter. You can plug a direct short into a GFI receptacle and it will not trip. If you are putting your test probes into the hot and neutral slots.... NOT ground.... and the GFI trips.... it's bad.
 

Last edited by PJmax; 03-17-18 at 11:20 PM.
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Old 03-17-18, 11:40 PM
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Originally Posted by PJmax View Post
Are you sure these are straight GFI receptacles and not ones with some kind of arc fault protection ?

I have never had a GFI trip when plugging in any test meter. You can plug a direct short into a GFI receptacle and it will not trip. If you are putting your test probes into the hot and neutral slots.... NOT ground.... and the GFI trips.... it's bad.
i have no idea if it is arc fault.
i will buy the plug in tester and see what that says.
the volt meter i am using is the kind with the probes.
tells me if it is live, voltage and AC or DC.
 
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Old 03-17-18, 11:45 PM
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box the outlet came in says,
leviton
N7599-RW
smartlockpro
 
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Old 03-18-18, 06:20 AM
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The tester that Xsleeper posted the link to will not work if there is no ground path to the receptacle. They have a resister between the hot and ground to create a ground fault. If there is no ground, it will not work.
 
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Old 03-18-18, 06:26 AM
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I thought he said..........

i am replacing all of the old BX and two prong outlets with ROMEX and three prong outlets.
 
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Old 03-18-18, 06:41 AM
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Yes he did XSleeper. I just want to point out one of the shortcomings of those testers for future readers.
 
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Old 03-18-18, 01:54 PM
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bought the tester .
just tried it with the load wires disconnected, and connected.
tester says it is wired correctly.
hit the test button on the tester, GFCI tripped.

at this point, should i just trust the GFCI tester and not try to fgure out why i tripped it with the probe type tester?
just assume i accidentally touched ground or something?
 
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Old 03-18-18, 01:57 PM
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and yes, it is grounded.
ROMEX ground wire and neutral wire to the breaker box neutral bar.
separate terminals.
 
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Old 03-18-18, 01:59 PM
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It should be fairly easy to use a probe type tester without touching ground.
Try it gain.
 
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Old 03-18-18, 10:08 PM
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just checked it with the probe type tester.
10 times to each pair of terminals for both outlets. i mean, the outlet can have two things plugged into it.
10 times to each pair of slots.
10 times to the bare ends of the wire which will be the next outlet.
did not trip.
 
 

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