GFCI Problem

Mark Osterbrink

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Aug 28, 2001, 9:21:52 PM8/28/01

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I added new high-output flourescent fixtures to my garage, and a GFCI outlet
on the same circuit. The GFCI is the first thing from the service panel.
Whenever the lights are turned on, the GFCI trips. I have taken it out, but
what would cause this? Is there some goofy load from the lights that would
trip it?

Gromit

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Aug 28, 2001, 9:34:53 PM8/28/01

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sounds like its wired wrong, recheck your wiring. If there is a wall switch
involved about half the time i screw it up.
"Mark Osterbrink" <no...@microsoft.com> wrote in message
news:QsXi7.66324$K6.26105791@news2...

Kevin Ricks

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Aug 29, 2001, 3:59:34 PM8/29/01

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It is generally not required or recommended that florescent or any
overhead lights, door openers, large appliances etc., be connected to a
GFCI circuit. All of these are known to cause false tripping when on
GFCI.

If you only have the one outlet and light fixture(s) then make a
'pigtail' on the source wires. Connect the source to the line side of
the GFCI and wire the switch/lights off the the source wires (pigtail).
Don't connect anything to the load side of the GFCI outlet.
If you add more general purpose outlets then you can connect them to the
load side so that the GFCI will protect them as well.
Kevin

NoEmail2Thisname

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Aug 30, 2001, 9:25:35 AM8/30/01

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After all, if you're in there at night the last thing you want is for the
lights to go out because your lathe tripped the GFI.

David Combs

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Sep 10, 2001, 2:47:46 AM9/10/01

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In article <3B8D5817...@netschools.net>,

Kevin Ricks <k...@netschools.net> wrote:
>
>It is generally not required or recommended that florescent or any
>overhead lights, door openers, large appliances etc., be connected to a
>GFCI circuit. All of these are known to cause false tripping when on
>GFCI.
>

Could you be a bit more specific about what and *why*
certain things screw up a gfci?

Like, we recently redid our kitchen ($$$!), and now
*every* outlet (I believe) is gfci'd.

We run microwave, refrig, sewing machine, you name it,
off the gfci.

What exactly is it *about* the gfci that makes it
interact poorly with eg fluorscent lighting?

Thanks

David

Chris Lewis

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Sep 10, 2001, 11:16:43 AM9/10/01

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According to David Combs <dkc...@panix.com>:

> What exactly is it *about* the gfci that makes it
> interact poorly with eg fluorscent lighting?

GFCI's react to very small (3-5ma) imbalances in current flow.

It is thought that certain types of devices that present a lot
of inductive load (motors, compressors, sometimes flourescent
balasts) or capacitive load can occasionaly "couple" enough
current to the ground, causing an imbalance, to cause the GFCI
to trip.

The truth of this isn't particularly well established. However,
the code recognizes that certain things suffer very adversely from
power interruptions (eg: fridges), and are usually grounded well
enough (third prong on the fridge and metal enclosure) to make the
GFCI's talents unnecessary. Thus certain exceptions in the code
to not require GFCIs for "large fixed equipment" etc.
--
Chris Lewis,
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