control voltage fed from remote located panel.

[keebo0825]

Where does the code address the issue of seperate control voltage from line/load voltage?
The control voltage for lighting contactors is shown on plans being fed from a panel some
200 feet from where the contactors are located.Also what seperate power source issues do we have to deal with?Plans also show 277 vac control going to some contactors switching 120 vac.

 

[lakee911]

As long as the minimum voltage rating on the conductors is higher than the maximum voltage you're using, you can mix conductors in the same conduit if that's what you're asking. You may need to derate for multiple CCC, but after going through the exercise, you might find that it doesn't matter for control. I don't allow mixing of power and control/signaling in my designs when I can help it. Check project specifications to see what they allow/disallow.

You can use interposing or pilot relays to interface different voltages, if necessary.

 

[jap]

I think he's talking about the power to the coil on the contactor coming from a different panel than where the power going through the contacts are coming from.

 

[tom baker]

There are requirements in Art 430 for disconnecting means at the control panel, or labeling. There may be similar requirements in the industrial control panel article 409. UL 508 has a similar requirement.
I prefer all the voltage in a control panel to be disconnected when the main panel disconnect is off. Sometimes this can be done with an aux contact.

 

[jap]

You run into the same scenario for instance in a 12p Lighting Contactor where there may be 12 seperate circuits going through the contactor and the control to the timeclock and photocell are tapped off of one of the circuits or a completely seperate circuit on its own.