gfci receptacle tripped by hotplate

[willdalrymple]

have finished several science rooms for a high school.where the hot plate is plugged into a gfci receptacle. the receptacle keeps on tripping. the draw listed for the hotplate is 11.3 amps. since the hotplate works on a non gfci receptacle why does it keep on tripping the gfci.

 

[andyrob]

Re: gfci receptacle tripped by hotplate

The nuetral in the hot plate may be connected to the frame of the hot plate. This would definetly trip the gfci. I had a similar experience with an electric charcoal starter. Unplug the hotplate and check for continuity between the nuetral and ground prong.
andyrob

 

[iwire]

Re: gfci receptacle tripped by hotplate

I agree with what Andy said and would add you may have a bad heating element that leaks current to ground.

In either case I would take the hotplate out of service till it was repaired.

 

[pierre]

Re: gfci receptacle tripped by hotplate

I would use a good GFCI tester to test for a possible bad GFCI. If it tests fine, I agree with the other posts and would definitely have it replaced, immediately.

Pierre

 

[earlydean]

Re: gfci receptacle tripped by hotplate

Years ago, I hooked up three receptacles in a tent for a weekend event at a local utility. The receptacles were for coffee pots. Saturday, I get a call to come NOW, as my receptacles were malfunctioning! I arrive to discover that nothing is wrong, except that the GFCI breaker would continually trip whenever the coffee pots were plugged in. Yet, the pots would work just fine inside the building. (They had to carry hot 50 cup pots out to the tent). It seems that they had filled the pots with a garden hose that morning, and the GFCI was just doing it's job. They never did agree with me, but the pots worked fine once they had dried off internally. Some people never get the point. I guess that is why we will always have a job!

 

[willdalrymple]

Re: gfci receptacle tripped by hotplate

my use of the word hotplate implies single,im sorry to inform you it was all of them. All 67 hotplates, and all 67 gfci reeptacles. As far as the neutral being bonded to the frame, why would this be done on a single pole unit. the only time i've seen this done is on a dryer plug. thats like bonding the "neutral" to the frame of a table top light fixture, wouldn't that energize the frame.

 

[bill addiss]

Re: gfci receptacle tripped by hotplate

will,

I would contact the Manufacturer to see what they have to say. It sounds like an issue with the Hot Plates.

I've witnessed a situation like Earl described where a Caterers' (brand New) Coffee Urns would not work in a (New) GFCI outlet.

The rules don't apply to your situation, but 525.23(B) seems to recognize that there are some appliances that are incompatible with GFCIs. Ask the Manufacturer.

Bill

 

[bennie]

Re: gfci receptacle tripped by hotplate

Do these hotplates have 3 wire cords?

 

[tom baker]

Re: gfci receptacle tripped by hotplate

With that number of hotplates its not possible to be a bad GFCI, which is unlikely anway.
This clearly is an issue for UL to evaluate. I would contact them or a nearby field office, make your comments in writing. Its important not to bypass the GFCI, if that is requested get it in writing and and explain why you can't comply. Be sure to keep your local AHJ informed.
its possible it could be a defective part, perhaps the mgf has change suppliers since it was first listed. I am assuming it is listed.

 

[willdalrymple]

Re: gfci receptacle tripped by hotplate

Bennie
yes these plates have your normal 3 prong plug

 

[tonyi]

Re: gfci receptacle tripped by hotplate

Check N-G prong ohms on one. If it isn't infinite, then they've got what amounts to a hardwired bootleg gnd internally which would almost certainly guarantee a trip on a GFCI.

[ December 06, 2003, 09:41 PM: Message edited by: tonyi ]

 

[david]

Re: gfci receptacle tripped by hotplate

I hate to ask because I assume you already know this. Are the GFCI Rec. being fed from a multi-wire circuit?

 

[iwire]

Re: gfci receptacle tripped by hotplate

GFCI outlets will work fine on a multiwire branch circuit.

GFCI breakers are another story.

 

[david]

Re: gfci receptacle tripped by hotplate

Bob

You are correct the only time I seen this kind of a tripping problem was with a GFCI protected recs. fed by multi wire circuits.

I guess this could be an equipment problem for that many to be involved. The unlikely ness of the equipment ground touching the neutral or faulty GFCI rec. all seem to be ruled out by the Nos. involved.

Reaching to the far side, the only other unlikely thing that comes to mind is if this was a remodel using metal old work boxes and hold its if the holding straps where not crimped tight to the box that might short the neutral to ground

I am out of Ideas on this.

[ December 07, 2003, 01:47 PM: Message edited by: david ]

 

[bennie]

Re: gfci receptacle tripped by hotplate

Use hot plates with 2 wire cords, when a GFCI is involved, or remove the GFCI's.

 

[gwz2]

Re: gfci receptacle tripped by hotplate

67 GFCI's and 67 Hot Plates ?

Something has to be wrong with the wiring after the GFCI's.

I doubt if 2W cords are going to correct the fault(s).

gwz2

 

[bennie]

Re: gfci receptacle tripped by hotplate

willdalrymple: Do the hot plates trip immediately? or after they are glowing?