Single Condutor in cable Tray- Equipment Ground Conductor Requiremnt

[faresos]

NEC 392.10(B)(1)(a) indicate the single conductors smaller 1/0 AWG are not allowed for use on cable trays in industrial establishments. Article 392.22(B)(1)(d) doesn't recognize any conductors less than 1/0. I have a feeder run that consists 4#3/0 & 1#3Gn (single conductors) that will be installed on cable tray. My question is: does the limitation of using minimum size conductor (#1/0) is also includes the equipment ground conductor? in another word, do I have to change the #3G conductor to 1/0 or there is an exception for equipment ground conductors that we can use smaller size than 1/0?

Thanks,

 

[Carultch]

NEC 392.10(B)(1)(a) indicate the single conductors smaller 1/0 AWG are not allowed for use on cable trays in industrial establishments. Article 392.22(B)(1)(d) doesn't recognize any conductors less than 1/0. I have a feeder run that consists 4#3/0 & 1#3Gn (single conductors) that will be installed on cable tray. My question is: does the limitation of using minimum size conductor (#1/0) is also includes the equipment ground conductor? in another word, do I have to change the #3G conductor to 1/0 or there is an exception for equipment ground conductors that we can use smaller size than 1/0?

Thanks,

You can use listed PV wire of any size in a cable tray. 690.31(C)(2)

 

[faresos]

Found Article 392.10 (B)(1)(c) which states equipment grounding conductors are permitted in cable trays and needs be #4AWG or larger. Does the equipment ground needs to be TC rated?

 

[ptonsparky]

Found Article 392.10 (B)(1)(c) which states equipment grounding conductors are permitted in cable trays and needs be #4AWG or larger. Does the equipment ground needs to be TC rated?

Is there any reason you could not use bare stranded CU for your EG?

 

[faresos]

The feeders will be transitioned from cable tray to conduits so I have to have insulated equipment ground for each run. Do they make #3 TC rated?

 

[Carultch]

The feeders will be transitioned from cable tray to conduits so I have to have insulated equipment ground for each run. Do they make #3 TC rated?

Just use #3 PV wire and you are good to go, assuming NEC2014 applies.

 

[roger]

Does the equipment ground needs to be TC rated?

No.

The feeders will be transitioned from cable tray to conduits so I have to have insulated equipment ground for each run.

Besides the requirement of 392.10(B)(c), why would it need to be insulated just because it's going in a conduit?



Roger

 

[faresos]

Just use #3 PV wire and you are good to go, assuming NEC2014 applies.

This section applies to PV system and for outdoor applications. I'm not sure if this will be acceptable by the AHJ for indoor application.

 

[Carultch]

No.

Why would it need to be insulated just because it's going in a conduit?

Roger

Bare wires cause abrasion during pulling. Not an NEC requirement, but possibly a job spec or an experience judgement call.

 

[faresos]

No. (Roger, is there any section in the code says it doesn't have to be or this is just from your passed experience with this type of installation?

Why would it need to be insulated just because it's going in a conduit? (it doesn't have to be but that's what the client requested)

Roger

Thanks,

 

[roger]

Bare wires cause abrasion during pulling. Not an NEC requirement, but possibly a job spec or an experience judgement call.

I've never had that problem pulling bare copper.

Roger

 

[roger]

Roger, is there any section in the code says it doesn't have to be or this is just from your passed experience with this type of installation

Faresos, simply by the allowance to use a "bare" conductor implies the EGC does not need any special listing.

Roger

 

[faresos]

Faresos, simply by the allowance to use a "bare" conductor implies the EGC does not need any special listing.

Roger

Thanks Roger and I agree with your statement.

 

[Andrew445]

You can use listed PV wire of any size in a cable tray. 690.31(C)(2)

Which ampacity rules would apply to small single conductors if not explicitly stated in 392? My opinion is that I can follow the rules for multiconductor cables as a conservative take. Using 65% of free air table is arguable as well.

 

[Carultch]

Which ampacity rules would apply to small single conductors if not explicitly stated in 392? My opinion is that I can follow the rules for multiconductor cables as a conservative take. Using 65% of free air table is arguable as well.

This is uncharted territory in the the NEC. For the most conservative strategy, I would simply pretend it is in a raceway and follow the standard feeder ampacity calculation.