Self-Testing GFCI's

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bphgravity

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I'm reading in the recent EC&M (page 16) that starting July 2006, UL 943 requirements for gfci's will be revised again. One of the key features will be a self-testing function where the device simulates a ground fault every minute to check for proper internal operation. If the unit detects a problem, it shuts down. In addition, there will be a green light indicating the unit is performing properly, and a flashing red light which indicates the "end-of-life".

It also appears that in the event line-load connections are reversed, the unit will not supply power nor rest if the test button is pushed.
 
George Stolz

George Stolz

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Re: Self-Testing GFCI's

...It slices! It dices! It purees! :D

If it's reliable, great! If it's Arc Fault II: Revenge of the Factory then we'll have issues. :D
 
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greeny

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Re: Self-Testing GFCI's

I think a self-testing GFCI would be great. I have some 7.5 watt lamps that I use to test GFCIs. I test them, obviously, by putting them between the hot and ground(with a cord cap). Each lamp is good for 6 ma of current(class A UL standard trip rating is 4-6 ma) and I have never had a GFCI trip with only 1 lamp. 2 lamps cause them to trip ~60% of the time and 3 lamps trip them about ~90% of the time. Right out of the box they don't always trip at 12 ma!
 
don_resqcapt19

don_resqcapt19

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Re: Self-Testing GFCI's

Read the operational details for this device closely. No where does it say that the power is turned off when the device fails its self test. The only thing that happens is that the color of the indicator light changes. Is the end user going to stop using it when the color changes?
Don
 
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jjc3rd

Member
Re: Self-Testing GFCI's

I found this forum because I read an article in EC&M that discussed replacement of GFCI devices with "self testing models that have recently appeared on the market". They suggest replacement of GFCIs as failures are found. Can anyone tell me who is offering them? I would like to investigate how they work. Thanks!!

[ December 29, 2005, 08:34 AM: Message edited by: jjc3rd ]
 
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jjc3rd

Member
Re: Self-Testing GFCI's

It certainly appears that the device simply indicates that it has failed it's test (flashing red led) or is tripped. (solid red led). It also indicates that power is available with the green led. It does appear to offer the advantage of showing the user that it won't protect them but will not prevent a shock if the red led is flashing and a ground fault occurs. I suppose a manually tested device would do the same. If the device failed the test it would not trip and it's up to the user to replace the failed device. It would not prevent the user from drawing power from the device in either case.
 
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bthielen

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Re: Self-Testing GFCI's

I wonder how it simulates a ground fault without actually tripping? Seems a good test would require that the device actually respond to the test. If it didn't, would the test be truly valid?

Bob
 
don_resqcapt19

don_resqcapt19

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Re: Self-Testing GFCI's

Bob,
The following is from this Hubbell document.
The new Hubbell self-test ground fault receptacle directly addresses this concern. An internally generated simulated ground fault will enable the GFCI to check for proper operation of the unit every 60 seconds. This provision is a major feature that surpasses any existing design on the market. The validation test for GFCI functionality can now be performed automatically. This diagnostic feature literally tests & monitors itself by way of the electronic design. With this feature, the ability to provide people protection can now be verified on a continuous basis. This is a significant contrast when comparing the one time per month recommendation that is suggested today.
Click to expand...
 
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