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#45728 - 12/05/04 06:11 PM 2000 watt movie lamp trips GFCI
BigB Offline
Member
Registered: 03/31/04
Posts: 719
Loc: Tucson, AZ USA
I have a customer who's brother is in the filming business. He has a 2000 Watt lamp that he says trips the GFCI every time he powers it up. The filming area is all GFCI protected. The best explanation I can come up is the high inrush from the cold tungsten filament must be causing an imbalance between the line/neutral enough to trip the GFCI. I suggested using a dimmer to bring the lamp up slower.Am I even on the right track?
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#45729 - 12/05/04 07:03 PM Re: 2000 watt movie lamp trips GFCI
RobbieD Offline
Member
Registered: 02/23/03
Posts: 231
Loc: Canada
Is it a gfci breaker or receptacle? What is the rating of the breaker?
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#45730 - 12/05/04 07:06 PM Re: 2000 watt movie lamp trips GFCI
BigB Offline
Member
Registered: 03/31/04
Posts: 719
Loc: Tucson, AZ USA
It's a GFCI receptacle, 20 amp on a 20 amp ckt with downline receps on it's load side. The light works fine on a non GFCI 20 amp circuit. I thought at first maybe a ground/neutral fault in the fixture, then I thought about the inrush.
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#45731 - 12/05/04 07:15 PM Re: 2000 watt movie lamp trips GFCI
RobbieD Offline
Member
Registered: 02/23/03
Posts: 231
Loc: Canada
Well I know that some reactive circuits trip GFI's but if this is a total resistive circuit it should work fine. Is it a total resistive circuit? 16.6 A is high for that circuit anyway. But if its only on now and then it should be fine.

[This message has been edited by RobbieD (edited 12-05-2004).]
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#45732 - 12/06/04 04:08 PM Re: 2000 watt movie lamp trips GFCI
cpalm1 Offline
Member
Registered: 01/06/04
Posts: 66
if the light MUST be GFCI protected, and there are nobody else can think of a better idea, then try using a dimmer switch on the light. make sure it has a 2000 watt capacity. with the dimmer you could bring the bulb up to full power slowly, reducing the inrush.
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#45733 - 12/06/04 04:35 PM Re: 2000 watt movie lamp trips GFCI
GA76JW Offline
Member
Registered: 03/20/04
Posts: 193
Loc: Suwanee, GA USA
Quote:
16.6 A is high for that circuit anyway


Coming from the one 2000 watt lamp alone you have the 16.6 Amps, With basic ohm's law. let alone what else is on the circuit. It's probably a good chance it is overloaded.
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#45734 - 12/06/04 05:18 PM Re: 2000 watt movie lamp trips GFCI
smokumchevy Offline
Member
Registered: 02/14/03
Posts: 60
Loc: Ottawa, Ontario, Canada
Can you not just use a GFCI class 'B' instead to prevent nuisance tripping in this case?

-Greg
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#45735 - 12/06/04 07:01 PM Re: 2000 watt movie lamp trips GFCI
BigB Offline
Member
Registered: 03/31/04
Posts: 719
Loc: Tucson, AZ USA
"Coming from the one 2000 watt lamp alone you have the 16.6 Amps, With basic ohm's law. let alone what else is on the circuit. It's probably a good chance it is overloaded."

I thought it was a misconception that a GFCI receptacle will trip on overload. I thought it would only trip on ground fault.

I think I will ask him to let me check out the lamp, just to satisfy my curiosity.
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#45736 - 12/06/04 07:14 PM Re: 2000 watt movie lamp trips GFCI
RobbieD Offline
Member
Registered: 02/23/03
Posts: 231
Loc: Canada
Your right GFCI receptacles do not trip on overcurrent.
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#45737 - 12/07/04 10:32 AM Re: 2000 watt movie lamp trips GFCI
hbiss Offline
Member
Registered: 12/16/03
Posts: 886
Loc: Hawthorne, NY USA
Why are GFCI receptacles being used there anyway? This a kitchen show? I'm for using GFI's where required but if you use them everywhere because you are paranoid you are going to have problems like this.

-Hal
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