Is CL3R listing on cable exclusive of other class uses?

[Tradesmanx]

My project has an 18 AWG multiwire shielded carol cable running from an automatic transfer switch to a generator. The cable has 10 wires in it and the jacket is rated at 300 volts. It has a CL3R UL listing label on it. We put it in the same conduit with the 6AWG wires that exchange power between the transfer switch and generator. NEC 300.3(A)1 says ac and dc can run in the same conduit as long as the insulation rating of the wires match or exceed the highest voltage applied to any conductor. But, the Head inspector is saying the cable can only be used exclusively for class 3 purposes. The 8500 watt generator is clearly a class one device. He wants us to pull the carol cable out and run it in a different conduit. In fact, I'm not even sure that will satisfy him. He may want me to run 10 thhn wires through conduit. Presumably, the CL3R listing would prohibit using the carol cable for the generator at all. I think he is wrong. I think the CL3R listing simply means it can also be used for class 3 and it isn't exclusive to other uses. What should I make of this?

 

[don_resqcapt19]

My project has an 18 AWG multiwire shielded carol cable running from an automatic transfer switch to a generator. The cable has 10 wires in it and the jacket is rated at 300 volts. It has a CL3R UL listing label on it. We put it in the same conduit with the 6AWG wires that exchange power between the transfer switch and generator. NEC 300.3(A)1 says ac and dc can run in the same conduit as long as the insulation rating of the wires match or exceed the highest voltage applied to any conductor. But, the Head inspector is saying the cable can only be used exclusively for class 3 purposes. The 8500 watt generator is clearly a class one device. He wants us to pull the carol cable out and run it in a different conduit. In fact, I'm not even sure that will satisfy him. He may want me to run 10 thhn wires through conduit. Presumably, the CL3R listing would prohibit using the carol cable for the generator at all. I think he is wrong. I think the CL3R listing simply means it can also be used for class 3 and it isn't exclusive to other uses. What should I make of this?

Unless the control circuit is an Article 725, Class 1 circuit, it is not permitted in the same raceway as the power conductors, no matter what rating the cable may have. See the Informational Note that follows 300.3(C)(1).

 

[Tradesmanx]

Class 1 Device

Class 1 Device

Unless the control circuit is an Article 725, Class 1 circuit, it is not permitted in the same raceway as the power conductors, no matter what rating the cable may have. See the Informational Note that follows 300.3(C)(1).

So, the generator is a class one device. Are you saying the control circuit board could be rated different than the generator it is housed in? If not, then this is a class 1 circuit since the generator is a class one device and the device determines the class of the circuit (not the wire labelling). Correct?

 

[JFletcher]

Unless the control circuit is an Article 725, Class 1 circuit, it is not permitted in the same raceway as the power conductors, no matter what rating the cable may have. See the Informational Note that follows 300.3(C)(1).

How does 300.3(C)(1) forbid this? The generator is not running above 300V.

Tradesmanx, look up 725.136. and yes, the control board may be a class 2 circuit.

 

[hbiss]

My project has an 18 AWG multiwire shielded carol cable running from an automatic transfer switch to a generator. The cable has 10 wires in it and the jacket is rated at 300 volts. It has a CL3R UL listing label on it.

So you are saying that the jacket has 300V actually stamped on it? I find that odd because low voltage CL cables are not allowed to have a voltage rating marked on them because it leads to situations like this.

Or did you find that information on the internet?

-Hal

 

[don_resqcapt19]

How does 300.3(C)(1) forbid this? The generator is not running above 300V.

...

300.3(C)(1) does not forbid it, but the rules in Article 725 that cover the control circuit may. The only way they wouldn't is if the control circuit is an Article 725 Class 1 circuit.