can you install ground fault recps. in a residential home with a 120 volt two wire
system? will the gfi recp. work properly without the ground wire in the box?
Sam,
210-7(d) allows the repacement of existing 2 wire receptacles with GFCI receptacles where there is not an equipment grounding conductor in the box. The GFCI does not require an equipment grounding conductor to work.
Don(resqcapt19)
[Caution the basic statement I made is incorrect read the later post]
Sam,
One note to add to Don's coments is when a GFCI recp. is used where there is no ground available the test button will not work. This is because the test button uses the ground to inject a 5 miliamp ground fault to make the unit trip. I once had a GFCI that a coustomer requested to have replaced because the test button did not work, well the first two new units did the same thing and then I found the ground to be broken on the last box just up stream from the GFCI. Live and learn.
Dave T.
[This message has been edited by gto6t7 (edited 01-05-2001).]
This is another area that I do not agree with the NEC approving a product to install, that can not be easily tested, and the eventual failure can not be detected. It may or may not be functioning properly.
You're absolutely right Bennie, but the legal alternative would be to install another ungrounded two wire receptacle. I think I would prefer to take my chances with the GFCI. Has anyone ever seen those "monthly GFI test records" - that every electrician faithfully affixes to the panelboard cover - filled out?
Guys,
I think you are mistaken about the operation of the test button on a GFCI receptacle. The test load is placed across (one side on the line and the other on the load) the current transducer and will create the required current imbalance to test the device with or without an EGC. The plug in external tester will not function without an EGC.
Don(resqcapt19)
Don: You are exactly correct, I was thinking sideways again. I had just returned from a home inspection, and my thinking got confused when my hand tester did not trip the device.
I was trying to remember which would not cause the GFCI to trip. Thanks for the Reminder. Has anyone seen any of the new Leviton GFCI's out yet? Or heard anything?
Don,
You are right! As I think back it was about 5 years ago and an inspectors tester would not work so I tried mine and it also would not trip the GFCI. They say the memory is the second thing to go. I still have a problem with the general perception some people have about GFCIs. That is that they think a GFCI will protect people in all situations that are dangerous. True they are great in a ground fault but between the hot and neutral they are no diffrent than a non GFCI recp.
Dave T.
[This message has been edited by gto6t7 (edited 01-05-2001).]