ECN Forum Forums General Topics of the Trade General Discussion Area GFI Breakers

I was wondeing if anyone knew a good site about GFI breakers. I have installed a few but would like more information on them. The ones I have installed are on a snow melt system. 4 of them held but the 5 of them tripped out. I have never worked with them before. Thanks

Class A GFI trips at minimum (I think) 3 milliamp to maximum 5 milliamp. This is GFI protection for personnel. What you want for your application is a class B GFI which will hold until 30 milliamps. This is GFI protection for equipment. It will avoid nuisance tripping, but be prepared to pay a little more.

Sorry, I don't have any links. I hope this helps.

GFCI (ground fault circuit interrupters) is a specific term for products which are used for personnel protection. UL Standards for Class A GFCI listing requires these devices to trip when they sense a ground fault of 6mA or more. They must not trip on currents as low as 4mA. The actual maximum tripping time (for 6 to 264mA) is found by the formula T = (20/I)^1.43, where T is in seconds and I is in mA. UL also requires the test button on the GFCI to simulate a fault thereby indicating proper operation.

ALCI (appliance leakage circuit interrupter), a subset of GFCI devices, are intended for use with appliances such as hair dryers.

GFPE (ground fault protection - equipment)and ELCI (equipment leakage circuit interrupter) are generic terms used to describe devices which protect at the 30mA level.

GFP (ground fault protection) is a catch all phrase for any ground fault sensing device. Many engineers use this term to define protection used for service entrance equipment, feeders, and large branch circuits. These devices are characterized by trip levels measured in Amps (not mA) and trip times in seconds. Also, these devices rarely interrupt the current directly, they are usually used to activate remote tripping of other protective devices.

I recently installed 4 GFI receptacles on a 20 amp circuit with a GFI circuit breaker. The circuit breaker kept popping and I traced the problem from the circuit breaker to the end, and realized that there were no shorts and the GFI circuit breaker didn't like it that I wired them all on with pigtails on the line side. I re-wired them all, going in on the line side, out on the load side, in on the next line side, out on the load, and so on, where each GFI was on the load side of the last one. It worked fine after that. I thought it was strange that the circuit breaker didn't like it when I wired it with pigtails.

... Spark Master, if you had (4) receptacles on the SAME circuit,protected by a GFCI breaker, why would you use GFCI receptacles,when you're already protected upstream..?? Sounds kinda redundant to me..?? I've found that GFCI's don't like to be installed in series,..it sorta "confuses" them,and gives you false trip status..

Russ

...[No thread hi-jacking intended,]...but can/should I use a GFCI receptacle on a 120 volt laundry circuit,.. ie;..gas fired washer/dryer..or does that create problems as well..? I've heard tell that GFCI's don't "like" motor loads,being that when the motor first starts up,the windings create a "faux" short for a split second,and the GFCI see'a that as a ground fault..Is this true..??
Russ

PS..You may now continue with your regular scheduled thread posting..The preceding was a Public Safety Message...




[This message has been edited by Attic Rat (edited 05-07-2004).]