UL Testing GFCIs

[big john]

Regarding external testing of GFCIs, I've often heard and believed that the only method to reliably test them was with the built in switch.

Reading this OSHA interpretation, it actually sounds like that a tester listed to UL 1436 is a recognized method of verifying positive operation. Unfortunately, I don't have access to that text, so I don't know exactly what those requirements are.

Any thoughts on this? Is the "test button only" just related to manufacturers requirements?

 

[starbolin]

Regarding external testing of GFCIs, I've often heard and believed that the only method to reliably test them was with the built in switch.

True up through 1994 apparently. Not true starting 1997. Would there be an issue with a device, probably the device manufacture would argue for the 'built in switch only' rule but if tested with a UL1436 compliant device one would have at least on leg to stand on.

Reading this OSHA interpretation, it actually sounds like that a tester listed to UL 1436 is a recognized method of verifying positive operation. Unfortunately, I don't have access to that text, so I don't know exactly what those requirements are.

With a listed device one would not need the text of the UL standard to properly use the device and perform the test. One would only need the device and the operating instructions. That is usually on of the requirements of the listing.

Any thoughts on this? Is the "test button only" just related to manufacturers requirements?

 

[big john]

...With a listed device one would not need the text of the UL standard to properly use the device and perform the test. One would only need the device and the operating instructions. That is usually on of the requirements of the listing.

Fair point, but my understanding is that a listing is not necessarily a certificate of functionality, merely a certificate of safety.

So I guess my concern was that a UL listed tester may be safe, but still may not be performing an effective test, that's why I was interested to see what 1436 actually requires these testers to do.

 

[GoldDigger]

Fair point, but my understanding is that a listing is not necessarily a certificate of functionality, merely a certificate of safety.

So I guess my concern was that a UL listed tester may be safe, but still may not be performing an effective test, that's why I was interested to see what 1436 actually requires these testers to do.

Among other things an external tester for a receptacle GFCI would have to have an independent ground connection to use as a current sink, since it could not rely on there being a ground present at the receptacle itself.
Now for new wiring and portable tool connections during construction, you would be able to rely on the receptacle or cord ground, or else the installation would be non-compliant for reasons other than just the GFCI functionality.