I have some new wiring runs and was doing some checking before
connecting to mains when I discovered that a 9V battery was pushing 25
or so micro-amps down a circuit that was supposed to be open, as
nothing was plugged into the GFCI outlets and and lamp sockets were
also empty. This was causing a reduction in voltage due to the battery
being loaded. Looking further, I found that each GFCI (there are 3 in
parallel in this circuit) had continuity from live to neutral and
showed a resistance of about 360 Ohms on a DMM, causing about 120 Ohms
at the end that is supposed to go into the breaker panel. The GFCIs are
made by Pass & Seymour (also says Legrand on the box). Their website
doesn't address this issue. These are their "premium" line and have an
LED on the front. A Leviton GFCI without any LED shows an open between
the live and neutral.

I don't know if all the GCFIs I bought can be simultaneously defective;
or whether the LED or their current monitoring circuit us causing the
continuity. 360 Ohms seems an awfully low resistance to show to 120V
AC. Is the behavior under DC different than AC for a GFCI outlet? Seems
pretty spooky...

Nexus7 wrote:
I have some new wiring runs and was doing some checking before
connecting to mains when I discovered that a 9V battery was pushing
25
or so micro-amps down a circuit that was supposed to be open, as
nothing was plugged into the GFCI outlets and and lamp sockets were
also empty. This was causing a reduction in voltage due to the
battery
being loaded. Looking further, I found that each GFCI (there are 3 in
parallel in this circuit) had continuity from live to neutral and
showed a resistance of about 360 Ohms on a DMM, causing about 120
Ohms
at the end that is supposed to go into the breaker panel. The GFCIs
are
made by Pass & Seymour (also says Legrand on the box). Their website
doesn't address this issue. These are their "premium" line and have
an
LED on the front. A Leviton GFCI without any LED shows an open
between
the live and neutral.

I don't know if all the GCFIs I bought can be simultaneously
defective;
or whether the LED or their current monitoring circuit us causing the
continuity. 360 Ohms seems an awfully low resistance to show to 120V
AC. Is the behavior under DC different than AC for a GFCI outlet?
Seems
pretty spooky...


you might be seeing the load of the internal power supply inside the
GFI that power the GFI itself.

the DMM is probably seeing the completly discharged filter cap inside
the GFI which will charge up and draw less current when you connect it
to the AC line.

Mark

I received a reply from Pass & Seymour's technical support. As part of
their "line load reversal test procedure," there is a small resistor in
the GFCI that makes it trip when the outlet is first energized. I don't
know if this procedure refers to what happens when first energized, or
if it is some other test that is performed during the manufacturing
process.

In any event, I (bench) tested this on one outlet, then on the curcuit
described. All 3 outlets duly tripped and the lights came on. After
resetting, all are open between L and N, and the circuit is functioning
correctly.

Thanks to all those who replied.

Why do you have 3 GFCI outlets on the same circuit? Only the first one on
the line needed to be a GFCI and it would protect all the other outlets
after it. You could also use a single GFCI breaker and then all the outlets
on that branch circuit would be protected. At least that's the way mine
work.
I am glad to here you solved your problem though, I would have been
surprised as well at the reading. They really should document that.

Bill

"Nexus7" wrote in message
oups.com...
I received a reply from Pass & Seymour's technical support. As part of
their "line load reversal test procedure," there is a small resistor in
the GFCI that makes it trip when the outlet is first energized. I don't
know if this procedure refers to what happens when first energized, or
if it is some other test that is performed during the manufacturing
process.

In any event, I (bench) tested this on one outlet, then on the curcuit
described. All 3 outlets duly tripped and the lights came on. After
resetting, all are open between L and N, and the circuit is functioning
correctly.

Thanks to all those who replied.

Bill Renfro wrote:
Why do you have 3 GFCI outlets on the same circuit? Only the first
one on
the line needed to be a GFCI and it would protect all the other
outlets
after it. You could also use a single GFCI breaker and then all the
outlets
on that branch circuit would be protected. At least that's the way
mine
work.

I figured if I did it that way, diagnosing a trip or other condition
would required knowing about the upstream outlet. I tried to minimize
such "non-local" effects by just putting GFCIs anywhere that no major
appliances would be plugged in. They were $10 on sale anywway. It's
too bad I have keep some shared neutral circuits because of legacy
issues, another instance where you have to know about the entire system
to work on just part of it.

"Nexus7" writes:

Bill Renfro wrote:
Why do you have 3 GFCI outlets on the same circuit? Only the first
one on
the line needed to be a GFCI and it would protect all the other
outlets
after it. You could also use a single GFCI breaker and then all the
outlets
on that branch circuit would be protected. At least that's the way
mine
work.

I figured if I did it that way, diagnosing a trip or other condition
would required knowing about the upstream outlet. I tried to minimize
such "non-local" effects by just putting GFCIs anywhere that no major
appliances would be plugged in. They were $10 on sale anywway. It's
too bad I have keep some shared neutral circuits because of legacy
issues, another instance where you have to know about the entire system
to work on just part of it.

So, now you will have some random combinatino of GFCIs tripping, rather
than only one.

Realize that there is no guarantee that only the GFCI at the affected
outlet will trip!

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