Generac Generator Cable

[bcl]

1. Generac makes a cable for backup generators that integrates the feeders and control wires into one cable. It consists of Three #3AWG - One #8AWG - Six #18AWG (copper). This cable is meant to be used for generators rated 16-24 kW, protected with a 100 amp breaker (there are smaller versions as well for smaller generators). It is a fairly common product made by multiple manufacturers, although many electricians don't seem to know about it. I also see lots of electricians insisting that you must use #2 AWG for 100 amp feeder. I'm guessing that most of the time this is because they are not paying attention to 83% rule in 310.12(B). Am I thinking through this correctly?

2. My question also pertains to the bundling adjustment factors in 310.15(C)(1). My first thought was that they would have to be applied because of all the wires integrated in one cable. 11 wires would be 50% adjustment factor. Making those adjustments would make it impossible to use #3 copper for the 100 amp feeder, but I guess the control wires, even though they measure 240v, are not considered current carrying conductors because their only purpose is for monitoring voltage. I have not tested these control wires for current. Am I correct on this, or is there some other code that I'm missing that makes this cable an acceptable installation according to the NEC (even though AHJs may not allow it)?

 

[augie47]

I believe the terminations on the generac equipment are 75° so #3 Cu is good for the 100 am,ps.
If I am reading it correctly,an Exception to Art 336.10(9) exempts the derating rule for generator installations using this cable.

No doubt Generac did it's homework befiore submitting Code changes

 

[don_resqcapt19]

....

2. My question also pertains to the bundling adjustment factors in 310.15(C)(1). My first thought was that they would have to be applied because of all the wires integrated in one cable. 11 wires would be 50% adjustment factor. Making those adjustments would make it impossible to use #3 copper for the 100 amp feeder, but I guess the control wires, even though they measure 240v, are not considered current carrying conductors because their only purpose is for monitoring voltage. I have not tested these control wires for current. Am I correct on this, or is there some other code that I'm missing that makes this cable an acceptable installation according to the NEC (even though AHJs may not allow it)?

Take a look at the last paragraph of 310.15(B)(3) in the 2017 code or 310.15(C)(1) in the 2020.

 

[Todd0x1]

is there some other code that I'm missing that makes this cable an acceptable installation according to the NEC (even though AHJs may not allow it)?

I have not had any direct experience with this cable, however my guess is it would be one of the AWM types for external connection of equipment and is part of the UL listed combination with the generator and transfer switch. Probably has a TC-ER jacket as well.

 

[don_resqcapt19]

I have not had any direct experience with this cable, however my guess is it would be one of the AWM types for external connection of equipment and is part of the UL listed combination with the generator and transfer switch. Probably has a TC-ER jacket as well.

It is listed as TC cable, and is not specific to generator equipment.

 

[Todd0x1]

It is listed as TC cable, and is not specific to generator equipment.

good to know thanks

 

[LarryFine]

I prefer (paying for) individual wires, especially for the control wiring.

 

[bcl]

I believe the terminations on the generac equipment are 75° so #3 Cu is good for the 100 am,ps.
If I am reading it correctly,an Exception to Art 336.10(9) exempts the derating rule for generator installations using this cable.

No doubt Generac did it's homework befiore submitting Code changes

I agree on the 75 degree terminals. I just haven't looked recently to see where it was stamped, but most of them are pretty plainly visible. Thanks for the 336.10(9) code reference. I probably would have gone awhile without coming across that exception. Very useful for talking to AHJs.

 

[bcl]

Take a look at the last paragraph of 310.15(B)(3) in the 2017 code or 310.15(C)(1) in the 2020.

Great reference, thank you! Generac references the bundling rule in their documentation, but I had missed derating only applying to power and lighting conductors.

 

[bcl]

I have not had any direct experience with this cable, however my guess is it would be one of the AWM types for external connection of equipment and is part of the UL listed combination with the generator and transfer switch. Probably has a TC-ER jacket as well.

Yes it's got a TC-ER jacket and is even suitable for direct burial. (I'll still probably put it in a raceway).

 

[bcl]

I prefer (paying for) individual wires, especially for the control wiring.

I would tend to agree with you, but I'm installing these by myself a lot of times, and pulling one cable is way easier than 3 individual current carriers, 6 control wires, and a ground. The generator cable is $8-11 per foot, but it saves quite a bit of time.

 

[Hv&Lv]

I would tend to agree with you, but I'm installing these by myself a lot of times, and pulling one cable is way easier than 3 individual current carriers, 6 control wires, and a ground. The generator cable is $8-11 per foot, but it saves quite a bit of time.

Thats about where i would draw the line though unless the customer requests it.
last partial roll I bought was $5.70 Per foot

i have maybe 30’ left. hoping its long enough for a friend of mine to use, then im done.