Extending a circuit from reducded ground NM cable

[peter d]

Is there anything in the NEC that would prevent me from extending a circuit that is wired with the old NM cable with a #16 grounding conductor?

The closest I get to a solid "Not allowed" answer is 250.122(A)

Grey area perhaps....

 

[mdshunk]

I've wondered the same thing in the past, but I still don't have any trouble doing it.

 

[peter d]

I've wondered the same thing in the past, but I still don't have any trouble doing it.

Nor do I, but I wondered if there was any code reason that I shouldn't.

 

[Buck Parrish]

Grey area perhaps....

Yup..........:smile:

 

[iwire]

Is there anything in the NEC that would prevent me from extending a circuit that is wired with the old NM cable with a #16 grounding conductor?

The closest I get to a solid "Not allowed" answer is 250.122(A)

Grey area perhaps....

Not gray.....not allowed.

New work must conform to current code.









































IMO :grin:

 

[George Stolz]

That's your longest post in a long time, Bob.

 

[peter d]

That's your longest post in a long time, Bob.

Bob is very long winded.

 

[LarryFine]

Yep. That's a post that epitomizes the phrase "Talks a lot but doesn't say anything." :grin:

 

[realolman]

I thought my computer was screwed up.
Turns out it was just the operator.

 

[charlie]

Is there anything in the NEC that would prevent me from extending a circuit that is wired with the old NM cable with a #16 grounding conductor? . . .

The reason that the smaller grounding conductor is not permitted is that some 'electricians' were using the grounding conductor for a circuit conductor and they were failing due to their small size. There is actually nothing wrong with the smaller conductors if they were used correctly. This is evidenced by looking at the much smaller grounding conductors shown in the rest of Table 250.122.

In my opinion, extending an existing circuit to pick up a little load will comply with the Code. If a new addition is being picked up, that portion would have to comply to the Code that is in force. If there is any doubt, check with the local Code and the local AHJ since that is what governs electrical work whether it is considered maintenance or new. :smile:

 

[iwire]

In my opinion, extending an existing circuit to pick up a little load will comply with the Code.

IMO the above quote is in direct conflict with the quote below.

If a new addition is being picked up, that portion would have to comply to the Code that is in force.

I see no way to add say 25' of new NM to new 15 amp duplex in a new box utilizing a undersized ground back to the panel and meet the current NEC.

 

[charlie]

I see no way to add say 25' of new NM to new 15 amp duplex in a new box utilizing a undersized ground back to the panel and meet the current NEC.

Bob, the OP didn't say anything about running a 25 ft. addition; however, that would not present a problem. The new addition I am referring to is new construction, not just a new circuit extension. :smile:

 

[iwire]

Bob, the OP didn't say anything about running a 25 ft. addition; however, that would not present a problem. The new addition I am referring to is new construction, not just a new circuit extension. :smile:

Charlie I am not trying to be a PITA (it just happens:grin: ) but I really don't understand what your saying.

Here is the OP

Is there anything in the NEC that would prevent me from extending a circuit that is wired with the old NM cable with a #16 grounding conductor?

Any extension of an existing circuit is new work be it one inch or one mile. That being the case the extension IMO would have to be served with a full size EGC, not the existing 16 AWG EGC.

 

[peter d]

Any extension of an existing circuit is new work be it one inch or one mile. That being the case the extension IMO would have to be served with a full size EGC, not the existing 16 AWG EGC.

That's pretty much how I'm seeing it.

 

[M. D.]

Any extension of an existing circuit is new work be it one inch or one mile. That being the case the extension IMO would have to be served with a full size EGC, not the existing 16 AWG EGC.

Bob ,.would rule #3 of the mass code allow this, in your opinion?? I would guess not ,.it seems to both create one and increase the magnitude of an existing one.

Rule 3. Additions or modifications to an existing installation shall be made in accordance with this Code without bringing the remaining part of the installation into compliance with the requirements of this Code. The installation shall not create a violation of this Code, nor shall it increase the magnitude of an existing violation.

 

[iwire]

Bob ,.would rule #3 of the mass code allow this, in your opinion?? I would guess not ,.it seems to both create one and increase the magnitude of an existing one.

IMO it is not allowed in MA. :smile:

 

[charlie]

Any extension of an existing circuit is new work be it one inch or one mile. That being the case the extension IMO would have to be served with a full size EGC, not the existing 16 AWG EGC.

Agreed, it appears that I misunderstood. The extension would have to have a full size grounding conductor but could be fed from an existing circuit unless the extension is feeding new construction.