Ground Conductor Parallel Feed

[Jay Pai]

I have an existing application: 800A feed with (2) 3/C 500kcmil with a #2 gnd (does not comply with code). 800A equipment requires a #1/0 gnd. In order to comply, can i run a grounding conductor "outside" of multiconductor cable without having to special order cable with a #1/0 gnd?

 

[petersonra]

hm

hm

I have an existing application: 800A feed with (2) 3/C 500kcmil with a #2 gnd (does not comply with code). 800A equipment requires a #1/0 gnd. In order to comply, can i run a grounding conductor "outside" of multiconductor cable without having to special order cable with a #1/0 gnd?

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250.122 (F) Conductors in Parallel. Where conductors are run in
parallel in multiple raceways or cables as permitted in
310.4, the equipment grounding conductors, where used,
shall be run in parallel in each raceway or cable.

 

[petersonra]

hm

hm

I have an existing application: 800A feed with (2) 3/C 500kcmil with a #2 gnd (does not comply with code). 800A equipment requires a #1/0 gnd. In order to comply, can i run a grounding conductor "outside" of multiconductor cable without having to special order cable with a #1/0 gnd?

It says minimum message length is 10 chars. I guess it does not count stuff inside quotes.

250.122 (F) Conductors in Parallel. Where conductors are run in
parallel in multiple raceways or cables as permitted in
310.4, the equipment grounding conductors, where used,
shall be run in parallel in each raceway or cable.

 

[fc]

No they need to be with the supply conductors.

 

[infinity]

You could use the existing cables with a GFPE device on the feeder if it meets the requirements of 250.122(F)(2).

 

[Jay Pai]

This is where I am getting hung up..."in each raceway or cable". I interpret raceway to be for single conductor applications and not multiconductor. Therefore ground must be enclosed with supply conductors.

I have seen installations with a separate gnd conductor "wrapped" around multiconductor, looks goofy.

 

[petersonra]

This is where I am getting hung up..."in each raceway or cable". I interpret raceway to be for single conductor applications and not multiconductor. Therefore ground must be enclosed with supply conductors.

I have seen installations with a separate gnd conductor "wrapped" around multiconductor, looks goofy.

Its probably safe but I don't believe it meets the requirement about the ground conductor being IN the cable.

 

[petersonra]

You could use the existing cables with a GFPE device on the feeder if it meets the requirements of 250.122(F)(2).

wouldn't a feeder of that size likely come off a supply that had GFPE?

 

[Jay Pai]

fuses, no circuit breaker that has a gnd fault setting

 

[don_resqcapt19]

250.122(F)(2)(3) The ground-fault protection is listed for the purpose of protecting the equipment grounding conductor.

Are there any ground fault devices that are listed for this purpose?
Don

 

[Bob NH]

Wrapping Ground Makes a Cable

Wrapping Ground Makes a Cable

"I have seen installations with a separate gnd conductor "wrapped" around multiconductor, looks goofy."

"Its probably safe but I don't believe it meets the requirement about the ground conductor being IN the cable."

I think it could be considered that when a ground conductor is wrapped around a cable, the assembly comprises a new cable. Therefore, the ground conductor is part of (IN) the new cable.

Three wires together (triplex) is cable, and it doesn't have a jacket around all. The wrap serves the purpose of preventing someone from disconnecting one end and discarding it without knowing that it is associated with the other conductors.

 

[petersonra]

Are there any ground fault devices that are listed for this purpose?
Don

my 2002 code does not say this it says:

(3) The ground-fault protection is listed for the purpose.

It does not specify what purpose it is referring to.

 

[don_resqcapt19]

Bob,
There was a wording change in the 2005 code.
Don

 

[petersonra]

"I have seen installations with a separate gnd conductor "wrapped" around multiconductor, looks goofy."

"Its probably safe but I don't believe it meets the requirement about the ground conductor being IN the cable."

I think it could be considered that when a ground conductor is wrapped around a cable, the assembly comprises a new cable. Therefore, the ground conductor is part of (IN) the new cable.

Three wires together (triplex) is cable, and it doesn't have a jacket around all. The wrap serves the purpose of preventing someone from disconnecting one end and discarding it without knowing that it is associated with the other conductors.

I don't see that at all.

A cable assembly is a factory assembly. You can't just wrap something around it and claim it is good to go, unless you are going to get UL to list it that way.

<added>
If you look in the code book in chapter 3, every cable is defined. generally they are defined similar to the definition of NM cable.

Nonmetallic-Sheathed Cable. A factory assembly of two
or more insulated conductors having an outer sheath of
nonmetallic material.

Note that it is a factory assembly, not something you made up in the field. Note the conductors are located inside the sheath, not outside.