[Sparky305]

So we have a control cabinet for a chiller with 480V coming in. Coming out we have 2 480V circuits, and a 24V control wire circuit going to the roof (2 wires on the 24V)

I was told that its legal to put them in the same raceway as long as the insulation is rated the same. Both insulations are rated for 600V so I think I'm good there. Now, if we terminate in a box, I think we're supposed to put a divider to divide the voltages. (According to 404.8(B) I think) My question is this:

If we don't terminate in a box, but rather use it as a pull box (no splices), is it legal to not have a divider?

By the way, they both terminate in another control cabinet on the roof for a cooling tower. No dividers or anything but I think it's kinda silly that in a 1900 deep box I need a divider but in the big cabinet its ok that theyre together? How does this work?

 

[ponyboy]

What power class is the 24volt?

 

[Sparky305]

I'm not really sure what that means. Its the control circuit for the fans and **** on the roof

 

[Sparky305]

I'll see if I get some pictures from work tomorrow if it helps. It's pretty interesting stuff. We're providing power for a huge printing press. German equipment that operates at 400V 50hz, or 460V 60hz. The printing press requires this cooling system that sits on the roof in order to operate. I love this stuff

 

[ponyboy]

I'm not really sure what that means. Its the control circuit for the fans and **** on the roof

Read 725. It covers class 1,2, and 3 wiring. I don't have my book open but I'm pretty sure you can't mix certain class circuits with line voltage

 

[KGN742003]

You can reclassify the circuit and use all chapter 3 wiring methods.

 

[ponyboy]

You can reclassify the circuit and use all chapter 3 wiring methods.

That sounds interesting. Could you give an example please? I don't think I've ever heard of this

 

[sparkywannabee]

I'll see if I get some pictures from work tomorrow if it helps. It's pretty interesting stuff. We're providing power for a huge printing press. German equipment that operates at 400V 50hz, or 460V 60hz. The printing press requires this cooling system that sits on the roof in order to operate. I love this stuff

I would'nt get too excited. While the technology in a modern printing press is pretty amazing, it is a dying industry, thanks to these two a**holes named Bill and Steve. I have worked maintenance in what used to be a big printing plant for 20 years now and things have gone downhill bad. Its pretty rare to even hear of a new installation anymore, is it a web or sheetfed press. A KBA maybe.

 

[KGN742003]

That sounds interesting. Could you give an example please? I don't think I've ever heard of this

I can give a second hand example, tbh I've never gone through the code and verified it for myself.

The example comes from a Mike Holt video series. They were talking about a furnace and thermostat wires, basically all you have to do is permanently remove the class 2/3 designation from the control transformer and treat it like line voltage as far as wiring methods.

 

[Big John]

That sounds interesting. Could you give an example please? I don't think I've ever heard of this

725.130(A) exception 2.

I used to use it all the time to get away with running limit switch controls in the same conduit as power conductors. Basically if you remove all the class 2 labels, use class 1 methods, and it's functionally associated.

 

[danickstr]

i would say ask your inspector, since you beat the system with the high voltage wire, now you have to get him to signoff your pull box. I am betting he will have an opinion and want it done his way.