Bundled Class 2 wiring

[SceneryDriver]

I have a designer who wants to remote some Class 2 power supplies. He wants to place (20) runs of Class 2 16/4 cable in one pipe. Each cable will have a max load of 50W @ 24VDC. These would be factory-supplied leader cables, and the manufacturer has approved the idea, but I'm still skeptical with that many cables in one 2" pipe. That's 1kW spread across the cables more or less evenly. Perhaps I should spec a 3" pipe.

Manufacturer's logic is that 16awg is rated at 13A, and and with 40+ current-carrying conductors, the conductors are de-rated to 35%; that's 4.5A.

To say nothing of the terrible reality that will set in when we try to pull (20) leader cables into one pipe when they all have factory-installed connectors I have no interest in removing.

Thoughts?


SceneryDriver

 

[petersonra]

Code wise, IMO, there is nothing that prevents you from doing this. It may not be real practical.

The 1 kW is not dissipated in the wiring. That is the total load at the utilization device.

You have about 2 A in each #16 conductor. There is about 0.4 Ohms per 100 feet of conductor, or something like 1.6 Watts of heat generated per 100 of conductor.

 

[SceneryDriver]

Code wise, IMO, there is nothing that prevents you from doing this. It may not be real practical.

The 1 kW is not dissipated in the wiring. That is the total load at the utilization device.

You have about 2 A in each #16 conductor. There is about 0.4 Ohms per 100 feet of conductor, or something like 1.6 Watts of heat generated per 100 of conductor.

Thanks for the double check. I got the same results you did, but it still felt wrong somehow. As to pulling those cables through with the connectors already installed, that's a whole other another fight...


SceneryDriver