> Yes, lightning can damage GFCIs I had one destroyed in my house. It punched a
> hole from a phase electrode right into the side of the solenoid and out the
> other to ground. Not much that lightning can't take out.
>
> The test you suggested is just that done by the test button. It connects a
> resistor from load side phase to ground. You could go further with a variable
> resistance to characterize the exact trip point, but I doubt the setpoint is
> likely to change much. Lightning would be more likely to destroy it or not,
> instead of readjust it.
>
> GFCIs come in at least a couple varieties. Some trip when activated. Most
> residential ones are this type. The disconnect solenoid needs to be tripped to
> disconect. With these, testing is necessary to verify they are able to measure
> and trip under leakage conditions. Others have a solenoid which is energized
> while set. They have to be manually set after power is on. These will trip if
> power fails or the electronics otherwise fails to keep the solenoid energized.
> These types are favored if there is a chance of an open neutral on the supply
> side of the GFCI, for example GFCIs used at the end of extension cords.
>
> Bob Johnson
> Ned Devine wrote:
>
> > Hello,
> >
> > Recently my house got struck by lightning. One of the things that happened
> > was that all of the GFCI's tripped. I reset them and tested them (pushed
> > the little test button) and they seem to work.
> >
> > My neighbor stated that when their old house got struck by lightning all of
> > the GFCI's were damaged. They did not find out till they went to sell it 3
> > years later and it failed the electrical inspection. Now, she is a software
> > engineer, so I am taking her comments with a grain of salt :-), but....
> >
> > Does anyone know if lightning could damage the GFCI's so that they would
> > test OK but still not work? If I want to test the GFCI's, could I just hook
> > a 15 k ohm, 5 Watt resistor from line and neutral to ground? Has this
> > happened to anyone else?
> >
> > Ned Devine
> > Entela, Inc.
> > Program Manager III
> > Phone 616 248 9671
> > Fax 616 574 9752
> > e-mail [email protected]
> >
> > PS The EMC testing you do is working. Most of the new electronics
> > survived. The only newer items that died were the garage door opener and
> > the cordless answering machine.
> >
> > ---------
> > This message is coming from the emc-pstc discussion list.
> > To cancel your subscription, send mail to [email protected]
> > with the single line: "unsubscribe emc-pstc" (without the
> > quotes). For help, send mail to [email protected],
> > [email protected], [email protected], or
> > [email protected] (the list administrators).
--- Begin Message ---
Yes, lightning can damage GFCIs I had one destroyed in my house. It punched a
hole from a phase electrode right into the side of the solenoid and out the
other to ground. Not much that lightning can't take out.
The test you suggested is just that done by the test button. It connects a
resistor from load side phase to ground. You could go further with a variable
resistance to characterize the exact trip point, but I doubt the setpoint is
likely to change much. Lightning would be more likely to destroy it or not,
instead of readjust it.
GFCIs come in at least a couple varieties. Some trip when activated. Most
residential ones are this type. The disconnect solenoid needs to be tripped to
disconect. With these, testing is necessary to verify they are able to measure
and trip under leakage conditions. Others have a solenoid which is energized
while set. They have to be manually set after power is on. These will trip if
power fails or the electronics otherwise fails to keep the solenoid energized.
These types are favored if there is a chance of an open neutral on the supply
side of the GFCI, for example GFCIs used at the end of extension cords.
Bob Johnson
Ned Devine wrote:
> Hello,
>
> Recently my house got struck by lightning. One of the things that happened
> was that all of the GFCI's tripped. I reset them and tested them (pushed
> the little test button) and they seem to work.
>
> My neighbor stated that when their old house got struck by lightning all of
> the GFCI's were damaged. They did not find out till they went to sell it 3
> years later and it failed the electrical inspection. Now, she is a software
> engineer, so I am taking her comments with a grain of salt :-), but....
>
> Does anyone know if lightning could damage the GFCI's so that they would
> test OK but still not work? If I want to test the GFCI's, could I just hook
> a 15 k ohm, 5 Watt resistor from line and neutral to ground? Has this
> happened to anyone else?
>
> Ned Devine
> Entela, Inc.
> Program Manager III
> Phone 616 248 9671
> Fax 616 574 9752
> e-mail [email protected]
>
> PS The EMC testing you do is working. Most of the new electronics
> survived. The only newer items that died were the garage door opener and
> the cordless answering machine.
>
> ---------
> This message is coming from the emc-pstc discussion list.
> To cancel your subscription, send mail to [email protected]
> with the single line: "unsubscribe emc-pstc" (without the
> quotes). For help, send mail to [email protected],
> [email protected], [email protected], or
> [email protected] (the list administrators).
--- End Message ---
