new bathroom without a ground


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Old 08-18-14, 07:09 PM
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new bathroom without a ground

A neighbor is having a bathroom redone, and I'm looking for someone to double check my assessment of the contractor's work. They ripped out the drywall and flooring and are redoing everything from there.

There are a few lights switches and an exhaust fan switch and 1 GFCI outlet. I tested the outlet with a GFCI tester and it has an open ground. some of the switches are attached to new ground wires, some are not, but none of them are electrically grounded (volt tester from black to white measures 110v, from black to ground measures 0V).

The old wiring is bendable metal sheath with no ground wire inside, however I believe I saw the thin metal tab, which can be used for grounding. all the boxes are plastic (sigh). the new wire and the GFCI are 15amp, not sure about the old wiring. I did not check how many circuits are coming into the bathroom.

So obviously the reason I couldn't find an electrical ground is because they are using plastic boxes. Would they be ok if they used metal boxes, properly attached the old cables, and attached the new cables with a screw to the box?

I didn't check this, but in retrospect, I suppose it is possible that they attached the incoming old cable to the line side of the GFCI and then feed the rest of the bathroom off the load side. would this be an acceptable solution? Would you insist on metal boxes?

Thanks
 
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Old 08-18-14, 07:19 PM
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Your feathers are ruffled and rightly so. You can't extend a non grounded circuit and you certainly can't run metallic cable in to plastic boxes.

You can find a ground on plastic boxes..... check from hot to the ground pin of a receptacle or yoke of the device.

Is there a permit on the job...... there should be ?
 
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Old 08-18-14, 07:39 PM
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The grounding need to be continued with the use of metal boxes. This contractor sounds like a complete hack.

If the walls are completely open now is the time to run new grounded cables and new circuits.
 
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Old 08-19-14, 05:25 AM
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Best way to do this is to install a metal box at the first location where the circuit enters the room. From there you can bond the ground wire of the new NM cable to the metal box and carry the ground through and use plastic boxes for the rest. This is if the metallic jacket of the AC cable is grounded.

The new GFCI should be fed with a 20 amp circuit. I do understand that this can't be done without major demo so an AHJ might let it slide.
 
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Old 08-19-14, 07:35 AM
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Tolyn: The walls have been pulled off the studs. you can see the electrical boxes and the attic.
 
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Old 08-19-14, 07:51 AM
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Even less reason for the hack work since they have access to install the correct boxes.
 
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Old 08-19-14, 11:10 AM
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Yes, but is there a path back to the electrical panel to pull in a new circuit? If so, then a new 20 amp circuit should be installed.
 
 

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