Reduced Grounding Conductor Romex

[mkgrady]

I have a customer that is planning a large addition and some remodeling in his home. Parts of the existing home are wired in that original Romex that has the reduced ground wire. No sure but I think it runs half the size of the other conductors. He is asking me my opinion on whether or not he should consider replacing the old Romex even where he has no plans to remodel. To do this he would remove lots of the wall and ceiling surfaces. He does not want a lot of cutting and patching and snaking.

So my question is: Is it worth replacing the old romex and what would be the reason to do so? After all, all the larger sized Romex cables have a reduced grounding wire. I have told him the function of the grounding wire is to provide a way for the circuit breakers to trip in the event of a ground fault. He is smart enough to understand what that means as he is an HVAC contractor but I am having trouble deciding if the idea of rewiring is overkill. I guess the answer might lie in the reason the reduced wire is no longer available is sizes less than #10 Romex.

Any suggestions (other than just do it and make more money)? He is by far my best customer.

 

[iwire]

If it was my own home and the NM was still in good shape other than the smaller EGC I would not rip up walls to replace it.

 

[al hildenbrand]

I apprenticed during the very end of the reduced ground era. To say "reduced ground" turns the emphasis negative. The presence of an EGC in the NM was an overall increased requirement over the Code requirements of the prior era of non-EGC NM. That new fangled NM with Ground was a big safety improvement.

What are the available fault currents for this house. If the house is some distance from the PoCo transformer, the bolted short circuit current out on the end of a 14/2 or 12/2 branch circuit isn't going to be much, to begin with even with a full size EGC. If the branch circuit overcurrent protective devices have a good tight response curve, then the only thing I'd pay attention to is the splicing of the EGC conductors themselves.

I've seen examples of splicing EGC to EGC that was only twisting the conductors a few times. Bonding to steel boxes was something that I was taught later, and in another jurisdiction. So, what I'd suggest is a good run though of all the boxes to verify the splicing and bonding of the EGCs. Remember, the EGCs can be like spokes of a wheel, but can also be like a web, with multiple parallel paths.

I think the answer will be ultimately driven by what that original electrician did, back in the Sixties.

 

[ADV_Rik]

Al, I like your answer, well put.

 

[al hildenbrand]

Al, I like your answer, well put.

Thanks. :thumbsup:

 

[mkgrady]

Al, I like your answer, well put.

I agree. I find it very helpfull. Thanks

 

[HackElectric]

If the customer is willing to spend a little money for safety, I would check each connection. That thinner wire is easier to break, especially after a handyman or homeowner has been in the box replacing the device over the years.

Offer him a package to replace all the devices and at the same time check all the grounding/bonding and splices. That would be a good upgrade while saving him a fortune.

 

[mkgrady]

If the customer is willing to spend a little money for safety, I would check each connection. That thinner wire is easier to break, especially after a handyman or homeowner has been in the box replacing the device over the years.

Offer him a package to replace all the devices and at the same time check all the grounding/bonding and splices. That would be a good upgrade while saving him a fortune.

Good suggestion. I will do just that.

 

[Wenty4]

250.122 and table 250.122 tell you no egc smaller than #14, obviously for new wiring, which means no taps from the existing reduced egc cables. I have been calleed on this in Andover, MA, you may want to check with the AHJ for his opinion.

 

[iwire]

250.122 and table 250.122 tell you no egc smaller than #14, obviously for new wiring, which means no taps from the existing reduced egc cables. I have been calleed on this in Andover, MA, you may want to check with the AHJ for his opinion.

They are or were out of control in Andover.

Rule 3 says we don't have to do that but they seem to forget that.

 

[Knuckle Dragger]

All great responses! Right on with inspecting all the devices and connections.

I would not replace the wiring either as long as you believe the wiring system seems to be in good shape.

More than likely the EGC is spiral wrapped around the NM sheathing and the NM clamp is cranked down on that wrapped sheathing more than it should be. That path to ground is only as ground as it's weakest connection.

Side note: If you are replacing the devices on each circuit will you be upgrading them to ACI protected circuit or AFCI receptacles?

 

[al hildenbrand]

More than likely the EGC is spiral wrapped around the NM sheathing and the NM clamp is cranked down on that wrapped sheathing more than it should be.

Prior to the 1962 NEC, there was a shopping list of locations where receptacle outlets were required to be "grounding type" with the grounding terminal actually connected to an Equipment Grounding Conductor (EGC). The 1962 NEC simplified the issue by removing the shopping list of locations and, instead, saying that all new receptacle outlets had to be of the grounding type and had to be connected to an EGC.

So, the EGC in the NM with ground had to end up connected to the receptacle ground terminal.

In my personal experience, most of the NM EGCs were inside a green plastic insulation that required stripping before termination. Nonmetallic boxes were also in common use.

I never saw the NM EGC wrapped around the NM cable sheath to be squeezed by the clamp of a metallic box connector, with the notable exception of wiring done by unlicensed people. There was no end of creative "bad" installation done by them.

As I was taught in the late Sixties, the #16 NM EGC connection to the receptacle device grounding terminal also "bonded" the box (if it was conductive) through the device mounting screws. This was before auto ground yokes, and before device looseness was understood. My Master taught economy of motion, along with everything else, and the idea of stripping the excess of NM to get the length of EGC required to wrap around the sheath of the NM and then to run on to the device termination, and then stripping that extra length of green insulation, would have been a waste to him, as it simply wasn't a requirement.

Now, wrapping the bonding wire around the metallic sheath of Armored Cable, just after installing the anti-short bushing and before insertion into the cable clamp, THAT happened all the time. . .

 

[Ponchik]

Why not offer him the best solution (to rewire)? vs testing and making sure what is there is safe and will perform for the years to come.

Offer him rewire and the benefits and redo connection with device change and the benefits and let him decide.

 

[Knuckle Dragger]

I never saw the NM EGC wrapped around the NM cable sheath to be squeezed by the clamp of a metallic box connector, with the notable exception of wiring done by unlicensed people. There was no end of creative "bad" installation done by them.

I was informed during my apprenticeship in the early 80's that this practice was called "The Boston Wrap" and I have called it that ever since then. We would remove the clamp and try to pull the sheathing through the box or get our needle nose and gently pull at the EGC unwrap it and bond it properly. Sometimes that EGC would be engrained in the mineral/ cloth insulation from the clamp pressing on it so tight.
Hopefully it was exclusive to the New England area.
Maybe someone from Massachusetts has heard of it?

 

[iwire]

Hopefully it was exclusive to the New England area.
Maybe someone from Massachusetts has heard of it?

My brother went to a Massachusetts electrical trade school in the late 60s, the 'Boston wrap' was exactly what they taught him to do. hmy:

He never became an electrician, just another dangerous DIYer.

 

[mkgrady]

All great responses! Right on with inspecting all the devices and connections.

I would not replace the wiring either as long as you believe the wiring system seems to be in good shape.

More than likely the EGC is spiral wrapped around the NM sheathing and the NM clamp is cranked down on that wrapped sheathing more than it should be. That path to ground is only as ground as it's weakest connection.

Side note: If you are replacing the devices on each circuit will you be upgrading them to ACI protected circuit or AFCI receptacles?

I will be changing all the receptacles and switches. Is there a 2014 requirement that any changed receptacle be afci protected?

 

[mkgrady]

They are or were out of control in Andover.

Rule 3 says we don't have to do that but they seem to forget that.

I don't understand. You mean taps or extensions from old reduced ECG Romex are allowed?

 

[Smart $]

I will be changing all the receptacles and switches. Is there a 2014 requirement that any changed receptacle be afci protected?

210.12 (B) states where branch-circuit wiring is modified, replaced, or extended.

 

[al hildenbrand]

I will be changing all the receptacles and switches. Is there a 2014 requirement that any changed receptacle be afci protected?

210.12 (B) states where branch-circuit wiring is modified, replaced, or extended.

AND, 2014 NEC 210.12 (B) Exception says AFCI is NOT required if you "extend the conductors less than six feet" (think two or more pigtails in the switch or receptacle box.)

 

[Knuckle Dragger]

AND, 2014 NEC 210.12 (B) Exception says AFCI is NOT required if you "extend the conductors less than six feet" (think two or more pigtails in the switch or receptacle box.)

Ignorance is no excuse for me:dunce:. I did not read the exception to 2014 NEC 210.12 (B). Thanks for bringing me up to speed.