Replies

1. 
   DanH | Nov 24, 2009 05:06am | #1

   Install the GFCI. Then apply the "Ungrounded" sticker that came with the GFCI.

   A strong nation, like a strong person, can afford to be gentle, firm, thoughtful, and restrained. It can afford to extend a helping hand to others. It's a weak nation, like a weak person, that must behave with bluster and boasting and rashness and other signs of insecurity. --Jimmy Carter
1. 
   Hudson Valley Carpenter | Nov 24, 2009 10:51am | #3

   False alarm on my part, I guess.  I've had these GFCI receptacles in the kitchen and baths for years.  Although they test OK they've never tripped so I recently began wondering if they're supposed to be grounded via a green wire. 

   Someone told me that you need to drill a hole in the back of the box and use a screw to fasten a ground wire.  That's supposed to provide the same grounding as a three wire system. 

   As usual, I'm about as dumb as dirt about electrical stuff, particularly the old stuff.

1. 
   DanH | Nov 24, 2009 04:03pm | #4

   If there is a reliable ground available they should be grounded. Many moons ago the BX shell was considered a legal ground, so you could consider it "grandfathered". Best to test the ground integrity first, though, at least with a continuity test between the BX and a copper water pipe or some such.
   A strong nation, like a strong person, can afford to be gentle, firm, thoughtful, and restrained. It can afford to extend a helping hand to others. It's a weak nation, like a weak person, that must behave with bluster and boasting and rashness and other signs of insecurity. --Jimmy Carter

2. 
   gfretwell | Nov 24, 2009 07:39am | #2

   Is this really BX or is it type AC? (skinny little bonding strip in the jacket). If it is AC it has a ground, assuming proper installation.

3. 
   renosteinke | Nov 24, 2009 05:13pm | #5

   One does not need a ground path of any kind for a GFCI to work.

   With an old house, the first question is 'what sort of boxes were used?'  If the metal boxes have angled backs, and the wire splices are in the back of the box, wrapped in tape ... leave it be. There is not enought room in the box for a GFCI receptacle.

   Instead, use a GFCI breaker at the panel. That can be a bit tricky, and you may wind up having to use a $90 2-pole unit.

   The alternative is to add pigtails to the wires in the old box, and mount a surface box ("Wiremold") over the old box.

1. 
   Hudson Valley Carpenter | Nov 24, 2009 06:06pm | #6

   One does not need a ground path of any kind for a GFCI to work.

   Thanks Reno,

   That's all I really need to know at this point.  The GFCI receptacles all test and work as they should so I'm gonna leave 'em be. 

   Thanks to all for your replies. 

2. 
   Muteability | Nov 25, 2009 03:52am | #7

   Instead of a GFI breaker, another option is to install a GFI outlet upstream.My house has no ground wire in most of the original wiring (1956). I pulled the wires out of the panel and added a GFI outlet to each circuit that needed it. Looks a bit funny with three GFI outlets in the floor joist above the panel, but a three pack of GFI outlets was only $30 and breakers were $50+ each.

1. 
   renosteinke | Nov 25, 2009 04:34am | #8

   That's a nice theory .... but older homes can have some interesting wiring practices, especially when it comes to the neutral wires. His "upstream" might very well be in a light fixture.

   Sometimes that's the only practical option - on that I agree. Without knowing the house, it's hard to say.