Undersized EGC old NMB

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AC\DC

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Location
Florence,Oregon,Lane
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EC
Customer wanted to change out every single duplex receptacle to a 2 gang duplex receptacle, problem is its looks like AWG 16 for ground. No attic or crawl space access to comply with 250.130 (c) without some major removal of walls then I might as well just abandon them and surface mount receptacle were he needs.

I got a call into local AHJ to see if he will allow anything since I am not "extending" the circuit.

Any liability you see ( if AHJ allows) in just using what's there since at one time it was compliant.
 
I would use the old EGC and maybe add GFCI protection like you would for NM cable without an EGC.
 
AC\DC said:
Customer wanted to change out every single duplex receptacle to a 2 gang duplex receptacle, problem is its looks like AWG 16 for ground. No attic or crawl space access to comply with 250.130 (c) without some major removal of walls then I might as well just abandon them and surface mount receptacle were he needs.
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I don't see where 250.130(c) applies. You are neither extending the circuit or replacing an ungrounded receptacle. I think the ground wire is fine the way it is. I think you can just change the j-boxes to 2 gang and use the same cable.
 
With a smaller EGC keep in mind that you may need a faster breaker trip time due to increased touch voltage and EGC heating.

During a fault the touch voltage on any exposed metal will be 75 volts vs the normal 60 volts, thus the breaker trip should be reduced to 0.6 seconds vs 1 second:

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According to 240.92 B, 16 gauge copper can only handle 150 amps for one second, 195 amps for 0.6 seconds and 350 amps for 0.2 seconds going from 60*C to 150*C. As such make sure your breaker trips faster than these time limits at the furthest point in the run.

Thus, with all this said, I too vote for a GFCI breaker as it will fulfill all the above.
 
AC\DC said:
Ol

Ite push-o-matic can’t do that at panel.
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GFCI receptacle down the line where there is enough wire to keep the fault current under 5000 amps. Typical home run will do. This is because if I'm not mistaken GFCI receptacle devices can only safely break up to 5000 amps of current.
 
mikeames said:
What kind of cable is it?
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My house was built in 1962 and all 14 guage type NM cable ( romex ) with a #16 ground wire was installed. Kitchen outlets were on 12 guage.I asked inspectors about this years ago and at that time was acceptable. Every time I had a wall open I replaced it with 12/2 NM cable with a #12 bare copper ground wire. Hopefully during a short circuit the circuit breaker should trip in guess less than a tenth of a second. Numerous times I had long 16/3 extension cords open a breaker due to cord being cut. You might want to look into installing GFCI or AFCI protection especially in sleeping areas.
 
drcampbell said:
Likewise the original Pushmatic breakers, by Bulldog ... probably ... they didn't have an AIC rating at all.
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AIC ratings, as we know them today, are a product of the early 80s.
In the 50s molded case breakers had short circuit ratings of 5kA, but by the 60s 10kA was pretty much the industry standard for molded case circuit breakers, including those from ITE and FPE.
 
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