Control circuit with other power conductors.

[darekelec]

Hello everyone.
Is there a nec issue if I run control conductors (class 1, 120v) for relays' coils for lighting in same raceway with other power conductors? Or does my control circuit for relays has to be functionally associated with other conductors in raceway? It's on commercial project. Please type code reference.
Thank you

 

[don_resqcapt19]

Violation of 725.48(B)(1).

 

[darekelec]

What's a power-supply circuit? NEC Index and google do not show any explanation.
Thank you in advance.

 

[don_resqcapt19]

What's a power-supply circuit? NEC Index and google do not show any explanation.
Thank you in advance.

A circuit that supplies power to utilization equipment is a power supply circuit.

 

[petersonra]

as a practical matter there is no need to make these conductors class 1 conductors in the first place, and there is no real benefit to doing so.

 

[darekelec]

as a practical matter there is no need to make these conductors class 1 conductors in the first place, and there is no real benefit to doing so.

We wanted to save on adding a step down transformer and have a better mechanical protection using BX. But yes in general.

 

[Bjenks]

Hello everyone.
Is there a nec issue if I run control conductors (class 1, 120v) for relays' coils for lighting in same raceway with other power conductors? Or does my control circuit for relays has to be functionally associated with other conductors in raceway? It's on commercial project. Please type code reference.
Thank you

if the circuits in the conduit are for the lights that the relay is controlling then I would say yes as they are functionally associated. Otherwise no.

 

[darekelec]

To what extent I am not allowed to mix my conductors controlled by relays with other not associated power conductors. Can I install in same raceway or enclosure my load side of contactor wires with other power circuits? How about my line side feeding wires? They will originate at breaker box where I have all other branch circuits.

 

[Bjenks]

To what extent I am not allowed to mix my conductors controlled by relays with other not associated power conductors.

You can't as has been referenced multiple times above.

Can I install in same raceway or enclosure my load side of contactor wires with other power circuits?

If the load side is between 50V and 600V and is protected by a fuse/breaker then yes as it is the controlled wire and not a low voltage controlling wire.

How about my line side feeding wires? They will originate at breaker box where I have all other branch circuits.

Is this different than you original question as I thought it was a low voltage wire. When ever I have an issue with mixing LV and "Normal" Voltage for Relay control I try and make the relay a 120V relay which I can then put in the same conduit. So if you are running a remote time clock that controls outdoor lighting, then you can put the time clock control conductor and the site lighting conductors in the same conduit since they are both 120V to ground.

 

[petersonra]

there is no general prohibition on mixing wires that contain different voltage levels. there are some limitations on mixing limited energy circuits with power circuits.

 

[darekelec]

to further explain;
I have lights in gallery controlled by relays that go on or off with 1 switch (master) and some local switches.
So far I learned thank to Don that I am not allowed to mix my control leg (master switch leg conductors - class 1, 120V) with other conductors as per 725.48(B)(1).

I continue my inquiry if I can mix load and/or line side conductors for lights connected to the same relay with other wires not associated - receptacles for example in my case, that are on differed breakers.
If I am not allowed what does my feeding wires do in electrical panel?
It is confusing for me at this point cause the term 'power-supply circuits' is not defined anywhere and maybe cause english is my second language.
Or maybe because I am Polish and this is another Polish joke.

 

[don_resqcapt19]

First your line and load power wires can be mixed with each other and or with other power wires. If they are in raceways you will have to watch the derating that is required for over 3 conductors in a raceway or cable.
The Class 1 control wires can be mixed with the power wires that they control, but not with other power wires.
It would also be my opinion that the power conductors on the supply side of the controller are also functionally associated and that the Class 1 control conductors can be installed with those power conductors.

 

[Aleman]

I have been taught to keep low and high voltage separated. Generally 24VDC controls and the high voltage usually 480VAC. Most of my work is controls, building and wiring and installing control panels per
UL. I don't have a copy of the UL508A. But one thing the listing agencies look at is wire segregation in the panels. Usually field wiring will have separate raceways for the low and high voltage. It's not really
the voltage levels, it's just that we want to keep noise out of our control lines, so the AC and DC are separated. I am not aware of any code that requires the field wiring to be separated as far as controls
and power. But I won't mix them unless both control and power are both AC voltage.