480v 120v signal same conduit?

[dm9289]

Conduit with multiple conductors

I have 480v 3-#3 for a hydraulic
pump motor + ground

3-#10 wires 2 for hydraulic oil heater one ground

The above are in one conduit, I wanted to add 2-120volt control wires used to activate the oil heater. Thermostat in oil heater would activate #0 motor starter for heating element sending power on the #10 wires of course when motor would be running

According to 725.48 this seems ok has anyone had problems by doing this. This was not first choice long story short some mistakes in design by vendor with devices selected

 

[just the cowboy]

As long as wires are rated for highest voltage.

As long as wires are rated for highest voltage.

As long as the wires are rated for the highest voltage and you are ok with conduit fill you can mix them. Since it only a relay I see no problem doing it that way, if you were talking mixing signal wires with 480 then only a maybe.

 

[dm9289]

The 120v I guess is a signal wire used for the oil of a starter

 

[dm9289]

Coil of starter sorry

 

[kwired]

Won't say I haven't possibly cheated on this a time or two but 725.48 (B)(1) says "Class 1 circuits and power-supply circuits shall be permitted to occupy the same cable, enclosure, or raceway only where the equipment powered is functionally associated."

Run a raceway to a 480 volt motor - it is fine to run a control circuit that is associated with that motor in the same raceway.

Run a power circuit across a room and want to put a switch for some class 1 control circuit for a non associated motor in there because it is convenient and runs to the same area - not exactly in compliance with this section.

 

[GoldDigger]

Won't say I haven't possibly cheated on this a time or two but 725.48 (B)(1) says "Class 1 circuits and power-supply circuits shall be permitted to occupy the same cable, enclosure, or raceway only where the equipment powered is functionally associated."

Run a raceway to a 480 volt motor - it is fine to run a control circuit that is associated with that motor in the same raceway.

Run a power circuit across a room and want to put a switch for some class 1 control circuit for a non associated motor in there because it is convenient and runs to the same area - not exactly in compliance with this section.

If the relay box is properly protected by a branch circuit OCPD, I don't see a problem with wiring the 120 as a power circuit that "powers" a relay. Then no restrictions.
If you are making use of the "control" nature of the load to avoid some requirements for a more general power circuit, then you would be stuck.
JMO

 

[don_resqcapt19]

This is a Class 1 control circuit, and the question is if the control conductors are functionally associated with both the oil pump and the oil heater.