Strange behavior in a GFI circuit
 

I have a circuit protected by a GFI outlet. The circuit starts in a
downstairs bathroom, runs through a GFI outlet there, then heads
upstairs to a couple other bathrooms. The GFI outlet downstairs has
power, and the circuit breaker trips fine if you hit the test button.
The outlets in the upstairs bathrooms are all dead.

Last week, some carpet cleaners came while I was out of town. I
understand they had some kind of power trouble during their work (i.e.
they thought they had tripped a breaker). Turns out, they did not trip
a breaker in the box - nor were any of the GFI circuits that I know
about in the house tripped.

The strange thing is this... I get my handy voltmeter out, and the
"dead" outlets in the upstairs bathrooms all read 96 volts AC. I plug
in a night light, turn it on, and the voltage drops to zero. I
measured the voltage coming into the GFI outlet downstairs at 120
volts. I read the voltage leaving the GFI outlet downstairs at 120
volts. Upstairs, it's down to 96 volts. If I trip the GFI breaker and
test the outlets upstairs, they all read zero volts. So I'm pretty
darned sure this is all the same circuit.

What ever is wrong with this picture?

- David

Strange behavior in a GFI circuit
 

Assuming you have removed the downstairs GFCI outlet from the wall to test
the "load" terminals. If you get 120 volts and have nothing upstairs, there
is probably a break in the cable or the upstairs outlets are not connected
to that GFCI . Depending upon when your house was built, you could also find
GFCI outlets in the basement, outside, and garage, which could be connected
to and upstream of the bathroom outlets upstairs. My best guess though, is
that you have a defective GFCI outlet in the downstairs bathroom



wrote in message
oups.com...
I have a circuit protected by a GFI outlet. The circuit starts in a
downstairs bathroom, runs through a GFI outlet there, then heads
upstairs to a couple other bathrooms. The GFI outlet downstairs has
power, and the circuit breaker trips fine if you hit the test button.
The outlets in the upstairs bathrooms are all dead.

Last week, some carpet cleaners came while I was out of town. I
understand they had some kind of power trouble during their work (i.e.
they thought they had tripped a breaker). Turns out, they did not trip
a breaker in the box - nor were any of the GFI circuits that I know
about in the house tripped.

The strange thing is this... I get my handy voltmeter out, and the
"dead" outlets in the upstairs bathrooms all read 96 volts AC. I plug
in a night light, turn it on, and the voltage drops to zero. I
measured the voltage coming into the GFI outlet downstairs at 120
volts. I read the voltage leaving the GFI outlet downstairs at 120
volts. Upstairs, it's down to 96 volts. If I trip the GFI breaker and
test the outlets upstairs, they all read zero volts. So I'm pretty
darned sure this is all the same circuit.

What ever is wrong with this picture?

- David

Strange behavior in a GFI circuit
 

Strange behavior in a GFI circuit
 

The strange thing is this... I get my handy voltmeter out, and the
"dead" outlets in the upstairs bathrooms all read 96 volts AC. I plug
in a night light, turn it on, and the voltage drops to zero. I
measured the voltage coming into the GFI outlet downstairs at 120
volts. I read the voltage leaving the GFI outlet downstairs at 120
volts. Upstairs, it's down to 96 volts. If I trip the GFI breaker and
test the outlets upstairs, they all read zero volts. So I'm pretty
darned sure this is all the same circuit.

If you are using a digital meter the 96 volts you are getting is either some
leakage from the GFI or induced voltage. There is no solid connection.
Sounds like you need to replace the GFI socket.

Strange behavior in a GFI circuit
 

First guess....loose connection somewhere in the circuit, trouble
showed up due to the larger than normal household current draw required
by their equipment.

Solution; start w/ screw terminals in the "problem" outlet and work
back to the breaker. following the circuit path through the outlets
tightening the connections


second guess............bad GFI (but much less likely)

cheers
Bob

Strange behavior in a GFI circuit
 

Thanks all for the suggestions. I've replaced the GFI outlet already,
so I'm pretty sure that's not the culprit. I'll pull all the affected
outlets and see what I can see in terms of loose connections.

The house was built in 1994 or so and there are several circuits
protected by GFCI. There have been situations in the past where the
upstairs bathroom has gone dead, and resetting the box in the
downstairs bathroom was always the cure. There is definitely something
wonky going on in this path.

- David

Strange behavior in a GFI circuit
 

Dave-

when you track down the problem, let us know what worked.

cheers
Bob

Strange behavior in a GFI circuit
 

So, I went around the whole house, all circuits live, with my trusty
voltmeter. Figured some of the outside boxes must be tied in
somewhere. Found my way to the back deck and... 96 volts. The night
light test revealed a dimly glowing bulb. Ha! I've got you now!

Turned off the breaker, tested with the voltmeter, and out came the
outlet. Turns out it had some corrosion going on (one of the sides of
the box didn't seal particularly well, evidently) and one of the hot
wires came out pretty easily. It was one of those "jam the stripped
wire in the hole" sorts of recepticles. So, a quick trip to the
friendly local neighborhood Despot of Homes and all is well again.

I lined the gasket surrounding the new outdoor cover with some RTV
sealant this time around - we'll see how many years this one lasts.

- David

Strange behavior in a GFI circuit
 

Dave-

Great work! those backstab outlets suck!

screw terminals / screw clamps are the only way yo go.


cheers
Bob

Strange behavior in a GFI circuit
 

Inside lights and outside lights, if GFIs are used, should be on separate
ones.


wrote in message
oups.com...
So, I went around the whole house, all circuits live, with my trusty
voltmeter. Figured some of the outside boxes must be tied in
somewhere. Found my way to the back deck and... 96 volts. The night
light test revealed a dimly glowing bulb. Ha! I've got you now!

Turned off the breaker, tested with the voltmeter, and out came the
outlet. Turns out it had some corrosion going on (one of the sides of
the box didn't seal particularly well, evidently) and one of the hot
wires came out pretty easily. It was one of those "jam the stripped
wire in the hole" sorts of recepticles. So, a quick trip to the
friendly local neighborhood Despot of Homes and all is well again.

I lined the gasket surrounding the new outdoor cover with some RTV
sealant this time around - we'll see how many years this one lasts.

- David

Strange behavior in a GFI circuit
 

I understand the original builder still lives in my neighborhood...
perhaps I should take it up with him. :-) Might want to bring up the
subject of the plastic water pipes (what's that banned building
material from the early 90's again?) and the fact that they knock
whenever you turn the hot water on...

Ah, the joys of home ownership. :-)

- David

Strange behavior in a GFI circuit
 

I understand the original builder still lives in my neighborhood...
perhaps I should take it up with him. :-) Might want to bring up the
subject of the plastic water pipes (what's that banned building
material from the early 90's again?) and the fact that they knock
whenever you turn the hot water on...
Ah, the joys of home ownership. :-) - David

No. Things have changed over the years. When you buy a home, it becomes
*your* problem. Take up the challenge. Your electricity must be connected
to the earth. Your plumbing must have those little vertical extensions that
prevent knocking. So on. Look at it as a challenge. ;-)