Thermoplastic cloth over braid branch circuit wiring ground size

[tgari]

I have a 1958 build home with older wiring in good condition. Both the 12 and 14 awg wiring have ground conductors of a smaller gauge. I am having difficulty determining if this is within the NEC requirements.

Appreciate any input!

Tom

 

[infinity]

It was code compliant when installed so it can remain because it is grandfathered in.

Welcome to the Forum.

 

[LarryFine]

They were usually two gauges smaller, so the #12 had a #16 EGC, and the #14 had a #18 EGC.

 

[petersonra]

Stuff that old is a good candidate for replacement anyway. Jmnsho.

 

[infinity]

My last home built around 1960 had the same wiring. Over the years I replaced all of it room by room. I'm assuming that when they first started using the reduced EGC cables that they were tested to ensure that the smaller EGC would actually work and the OCPD would actually open.

 

[Speedskater]

Well 18AWG will carry 20 Amps of Fault Current for at least several minutes before its insulation starts to fail. Hope the breaker trips by then.
In fact 18AWG will carry 75 Amps before it becomes a fuse.

 

[Birken Vogt]

My grandparents' house built in the late 60s had this type of Romex. I understand code had changed by then but they were probably still on a prior code cycle when built. It looked identical in every way to modern Romex but had 16 ground and it was also encased in green plastic sort of similar to the way NM cable is constructed.

 

[Little Bill]

I worry more about the old crumbling insulation falling off then the small EGC.

 

[ramsy]

Well 18AWG will carry 20 Amps of Fault Current for at least several minutes before its insulation starts to fail. Hope the breaker trips by then.
In fact 18AWG will carry 75 Amps before it becomes a fuse.

So 1,000 people touching same raceway can get 100.mA thru the heart in parallel, if equip. ground (EGC) @ 60Hz AC can cycle 100 Amp fault before disconnect.

Same fault thru the heart --missing EGC-- is less a shock hazard if GFCI breaker can disconnect @ 6.mA, before hazard rises to 100 Amp.

That GFCI is a minimum safety standard for NEC 406.4(D)(2) that makes 2-prong wiring with no EGC safer for 1 person, than new construction that can kill 1,000 people.

 

[Speedskater]

GFCI's are about leakage current safety.
EGC's first task is Ground Fault safety.

 

[ptonsparky]

Dang.
I don't think I can find a branch circuit long enough to get 1000 persons in parallel. Esp if we maintain safe distancing practice.

 

[tom baker]

GFCI's are about leakage current safety.
EGC's first task is Ground Fault safety.

Please explain how an EGC works in a ground fault.

 

[tgari]

It was code compliant when installed so it can remain because it is grandfathered in.

Welcome to the Forum.

Thanks.

 

[Speedskater]

Please explain how an EGC works in a ground fault.

I thought that the primary task of the EGC was to trip the breaker if the Hot wire came in contact with any metal grounded object.
Did I miss something in the last half century?

 

[jim dungar]

I thought that the primary task of the EGC was to trip the breaker if the Hot wire came in contact with any metal grounded object.
Did I miss something in the last half century?

What if the fault was an arcing style where the current was low enough to look like a normal load?

 

[LarryFine]

What if the fault was an arcing style where the current was low enough to look like a normal load?

Then the AFCI manufacturers will convince the CMPs that they have the solution.

 

[ramsy]

Did I miss something in the last half century?

When people get electrocuted the resistance wont trip Thermal-Magnetic breakers.

Table 1 of URL below:
"It takes a thousand times more current to trip a 20-A circuit breaker than it takes to cause respiratory arrest."

Conduction of Electrical Current to and Through the Human Body: A Review

Objective: The objective of this article is to explain ways in which electric current is conducted to and through the human body and how this influences the nature of injuries. Methods: This multidisciplinary topic is explained by first reviewing electrical ...

www.ncbi.nlm.nih.gov