Sub-panel replacements

[rickgomes26]

Not sure if this is the correct forum but it is safety related...

In the jurisdictions you work in, is it required to have a four wire feeder when replacing a sub-panel? This could mean replacing the existing feeder. Are any of you allowing a separate EGC to be run along with the existing feeder to provide this?

In my area there are a lot of older homes with three wire feeders and no equipment grounds to the sub-panels. Because many of these new sub-panels will be used to run new circuits it is my opinion that the feeder should either be replaced with a four wire feeder (se cable installations).

Thanks and I look forward to your feedback...

 

[LarryFine]

Rick, check with the inspector, but, generally speaking, direct replacements are permitted to keep existing conditions.

In any case, a new feeder must be a 4-wire, regardless of whether the source is a 3-wire- or 4-wire-supplied panel.

 

[infinity]

Regarless of what the inspector says I wouldn't install the new panel on the old feeder. Seems like nothing more than putting a bandaid on it. IMO the enitre feeder and panel should be changed. Whether or not it's required is a different story.

 

[Buck Parrish]

Regarless of what the inspector says I wouldn't install the new panel on the old feeder. Seems like nothing more than putting a bandaid on it. IMO the enitre feeder and panel should be changed. Whether or not it's required is a different story.

Me too, In some cases you can use the conduit as your egc.
Most times it's easy just to remove the panel all together. Bring the few circuits to the new one.
Of course thier's a million ways to do it. Like skinning a cat.

 

[rickgomes26]

I'm an inspector here. We don't have an electrical specialist so I'm working with the boss to help with electrical "policy".

I would agree that just because you replace a sub-panel there's nothing in the code that says you MUST run a new feeder if there are no new circuits being run. I'm just testing the waters to see how its being done elsewhere.

From a code perspective once you start running new circuits in that panel you shall provide an ground fault path back to the source right?

 

[quinn77]

we always replace feeders if existing is 3 wire feeder to sub panel...no matter what. its our policy.

 

[jxofaltrds]

The 'sub' is new work so it must meet code.
4 wire required.
We cannot create an unsafe condition.

 

[rickgomes26]

Good feedback all...thanks

 

[LarryFine]

We cannot create an unsafe condition.

I don't believe a direct replacement is considered "creating" one if the original install was compliant.

We are allowed to use existing 3-wire feeders to separate buildings if originally compliant, aren't we?

And existing 3-wire major-applaince circuits?

And ...

And ...

 

[cowboyjwc]

I agree with Larry other wise you would have to install AFCI's when you do a service change and install a new 20 amp circuit when you replace a GFCI in the bathroom.

You guys that do change it, that's great, but the first time an inspector asked for it, others would be screaming bloody murder.

 

[rickgomes26]

Ok Larry and Cowboy...I agree that doing a direct replacement is not creating new circuits.

What do you do when you're adding NEW circuits to that panel? Now do you replace the feeder?

I have worked in a jurisdiction where they did in fact require bedroom circuits be upgraded to AFCI when doing a service change...I did NOT agree with that policy but that was from the Chief Building Official.

 

[Dennis Alwon]

Ok Larry and Cowboy...I agree that doing a direct replacement is not creating new circuits.

What do you do when you're adding NEW circuits to that panel? Now do you replace the feeder?

I have worked in a jurisdiction where they did in fact require bedroom circuits be upgraded to AFCI when doing a service change...I did NOT agree with that policy but that was from the Chief Building Official.

I don't believe a new circuit would be allowed to be run from a noncompliant panel. In terms of the afci-- again if you do not extend the circuit and just change the panel then the inspector has no right to demand afci protection.

I would not want the responsibility of using afci circuit on some of these all circuits. Who is responsible for uncovering the problem if one exists?

 

[jxofaltrds]

I don't believe a direct replacement is considered "creating" one if the original install was compliant.

We are allowed to use existing 3-wire feeders to separate buildings if originally compliant, aren't we?

And existing 3-wire major-applaince circuits?

And ...

And ...

Correct me if I am wrong but I though paralled conductors have not been allowed since 1934?

Very possible that egc(s) of the main panel and the 'sub' are connected in some junction boxes.

I am assuming that this 'sub' is in the same structure. I do agree on your examples.

 

[LarryFine]

I don't believe a new circuit would be allowed to be run from a noncompliant panel.

I wouldn't consider such a compliant-when-installed panel illegal to supply a new grounded circuit from.

 

[LarryFine]

Correct me if I am wrong but I though paralled conductors have not been allowed since 1934?

Very possible that egc(s) of the main panel and the 'sub' are connected in some junction boxes.

That doesn't apply to EGC's. They get paralleled all the time, especially in NM work.

Example: a kitchen counter receptacle and a switch in the same box on different circuits.

Or even the same circuit.

 

[jxofaltrds]

That doesn't apply to EGC's. They get paralleled all the time, especially in NM work.

Example: a kitchen counter receptacle and a switch in the same box on different circuits.

Or even the same circuit.

Larry

If egc(s) are connected with the 'neutral' after the main you have paralled conductors.

Using your example if the conductors in the box that you mentioned came from different panels (3 wire sub) you would have another path for the grounded conductor.