GFI on old BX cable

[orf]

I want to replace and old ungrounded outlet with a GFI outlet. The box is metal and it also contains a switch, the box is not bonded, the cable is BX. Can I simply install the GFI or do I have to do anything else? This is going to be inspected as part of a kitchen remodel so I'm not sure if I should touch the box for fear of opening a can of worms with the inspector.

 

[Reach4]

OK if labeled "No Equipment Ground".

https://terrylove.com/forums/index.php?posts/542439/

I hope there is enough room for the GFCI outlet in the box.

 

[Sponsor]

 

[Jadnashua]

I redid my mother's whole house by finding the first item on each circuit and replacing it with a GFCI device. I then replaced each 2-slot receptacle downstream with a grounded receptacle, and used the labels. Most of the old wiring was BX. When new, it probably did provide a ground, but over years, it no longer did. Newer BX cable has either a tracer in it to provide ground, or comes with an actual ground wire, but that was rare in older cables.

 

[Luke M]

Starting with the 2014 NEC Kitchens require AFCI. It might be easier to use dual function GFCI/AFCI breakers (assuming the receptacles aren't on a 3 wire circuit). Also note that dishwashers require GFCI.

Incidentally, you should get a (non-code-compliant) equipment ground via the old BX, but it will only work properly with a GFCI. That's because the old BX armor may not pass enough current to promptly trip a standard breaker, but it will trip a GFCI.

 

[hj]

I once worked on a residence where the ENTIRE neutral circuit was a piece of BX sheath, so it will handle a major load. The situation became apparent when it rusted off and I disconnected the water heater piping which then caused a loss of the neutral, (the resultant 240v burned out several appliances which were operating).

 

[Luke M]

I once worked on a residence where the ENTIRE neutral circuit was a piece of BX sheath, so it will handle a major load.

It takes >100A to instantly trip a 20A breaker.

 

[WorthFlorida]

....This is going to be inspected as part of a kitchen remodel so I'm not sure if I should touch the box for fear of opening a can of worms with the inspector.

Once you pull a permit for a remodel, that entire area must be brought up to code. The counter area (usually) will need two 20 amp circuits plus what was mentioned above. If there is an old outlet on a wall of the kitchen and the wall was not touched, it probably will pass. If you have an electric range it now requires a four wire conductor, but it's always up to the inspector.