Hello –
I thought I read that a switched duplex outlet will have a minimum amount of current running through it even when the switch is off. Is that true?
My garbage disposal trips my GFCI circuit breaker as soon as I plug it into the the switched receptacle. Is it time for a new disposer?
Thanks,
Richard
Replies
Your GFI breaker may have been wired incorrectly. The neutral for the circuit goes to the breaker and not the neutral bus bar. The curly white wire goes from the GFI breaker to the neutral bus bar to complete the circuit.
If your neutral wire goes directly to the neutral bus, the GFI will only see the hot going out and nothing coming in on the neutral side and will immediately trip due to this gross imbalance.
As for whether a switch will allow a slight current through: it better not.
However, certain evil occupancy sensors will use the ground as a return path and will use a slight amount of juice to operate their stupid electronics.
~Peter
Well, that was as clear as mud.SamT
Praise the Corporation, for the Corporations' highest concern is the well being of the public.
Peter -
Thanks for the reply. The GFCI breaker was/is wired correctly; the black and white to the load and neutral connectors, respectively, on the breaker and the pigtail to the ground bar.
Richard
I had a GFCI breaker that just did that. The slightest load on a dedicated circuit tripped it. We just had to replace it.
I originally thought it was the breaker, too. So I replaced it and I still had the immediate tripping problem which I traced to be the disposal dying and an incorrectly wired switched outlet. I've fixed the outlet and will replace the disposal tomorrow night.
Thanks for your post.
1) Better be false, or you have a bad switch.
2) Plug something else into the outlet and see what happens. Use a lamp, then a toaster or coffee pot.
SamT
Praise the Corporation, for the Corporations' highest concern is the well being of the public.
SamT -
Thanks for the reply.
The switch works for a light and/or a radio. The garbage disposal trips the GFCI even witht the switch off.
Richard
" on the breaker and the pigtail to the ground bar."It should not be connected to the ground bar, but rather to the neutral bus.But if this is a main panel then the ground bus is the neutral bus is the ground bus."The switch works for a light and/or a radio. The garbage disposal trips the GFCI even witht the switch off."The neutral is connected to the ground inside the disposal.It might be an internal fault.But check the cord connects and specially look for an stray "wiskers" of the stranded cord wire that might be sticking out or a nicked insulation..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill -
Thanks for the reply.
This just started happening last week. I check all of the outlets on the circuit until I discovered the fact that just plugging the disposal into the switched out tripped the GFCI breaker. I suspect that the disposal is dying after 16+ years. If I have to remove it to check the wiring, I might as well replace it and hope I get 16 years from the new one.
Richard
RichardThe fact that the disposer causes a trip with the switch open is very suspicious, unless, of course, the switch is defective. Plugging an appliance into an open (i.e. switch off) circuit should never cause a trip; if it does, something is wrong somewhere other than at the appliance.In a correctly wired circuit with the switch open, current would have to be flowing through the neutral which is (or should be) grounded at the panel, to ground at the disposer. Current doesn't flow without voltage, so one end or the other would have to be energized. I suppose in a poorly grounded panel the neutral could float high enough to cause the trip, but it wouldn't be my first guess. One thing that could cause such a situation is if the circuit were wired with the switch in the neutral instead of the hot (stupid, but it happens). Then there would always be voltage to drive a bit of leakage current in the disposer and cause the GFCI to trip.If you just replace the disposer with one that has less leakage current, you may just be re-masking the underlying problem. I suggest you get a qualified person to check it out.
Wrong! A neutral-ground short can cause a GFCI trip, even with the switch off.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Yup, I've seen it quite a few times. Don't know why, but that's how it is.
Ed
Only if the neutral (more properly referred to a the "grounded conductor") is at a high enough potential to cause 4-6 mA to flow when grounded at the disposal, since, as I'm sure you know, a GFCI works by detecting a current imbalance of 4 to 6 mA between the hot and neutral. In a normal simple circuit this should not be the case. Of course, all kinds of abnormal situations can and do occur, some dangerous, some not, but, to me, a trip caused by plugging into an open circuit is a situation that warrents a closer look. Better safe than sorry.
The GFCI has a 2nd sense coil that induces a 120 hz signal and will detect a N to G short without any "external current".http://www.codecheck.com/gfci_principal.htm.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
As Bill said, there's a second coil that creates a potential in the neutral line. This causes imbalanced current to flow if there's any downstream short between neutral and ground, even if there's no actual load.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I guess I didn't read the original question carefully. I thought the GFCI was a receptacle with a switch was in front of it, in which case there would be no power to drive the circuit that detects a neutral to ground short, but in reviewing the question, he did say GFCI breaker. My bad.
Thank you (and every else) for providing helpful information.
I justed wanted let you all know that the switched outlet was indeed wired incorrectly! I replaced both the recepticle and the switch with 20 amp ones since it is a 20 amp circuit with 12/2 romex. I even marked the 'hot' white wire.
Now I can tackle the disposal; a Waste King model with a 10-year warranty that was given a favorable recommendation by Consumer Reports.
Thanks again one and all...
Richard
Richardi,
Thanks for "closing the loop" on this issue. So often we never find out if our remarks were on the money or out in left field.
"I replaced both the recepticle and the switch with 20 amp ones since it is a 20 amp circuit with 12/2 romex."
Just for future reference, you can put 15A outlets on a 20A circuit if there are more than one outlet on the circuit.
Mike HennessyPittsburgh, PA