If the control wiring is Art 725 Class 1 wiring and functionally related, then yes. Class one wiring is wired with a chapter 3 wiring method.
I just replied to an RFI this morning with the following:
While NEC Section 300.3(C) allows conductors of different systems to share the same enclosure, cable or raceway, if the low voltage (control circuits) are considered an NEC Article 725 class 1 or 2, then the rules change.
The typical 120 V motor control circuit from a starter or MCC is class 1 remote control and signaling circuit, and is required to be wired with a chapter 3 wiring method, and can share the enclosure, cable or raceway if functionally related.
725.46
Class 1 circuits shall be installed in accordance with Part I of Article 300 and with the wiring methods fromt he appropriate articles in Chapter 3
725.48(1)
Class 1 circuits and power supply circuits shall be permitted to occupy the same cable, enclosure, or raceway only were the equipment is functionally related
An NEC Article 725 Class 2 is what is typically referred to as a low voltage circuit, most PLC input and output circuits are a class 2 circuit.
While 300.3(C) allows conductors of different systems to share the same enclosure, cable or raceway, NEC section 725.136(A) requires separation from light, power, and class 1 circuits from class 2.
A fine print note to 300.3(C) refers to 725.136(A), and section 90.3 tells us the rules in chapter 7 may amend the rules in chapter 1-4
To summarize, if the "low voltage" circuits are considered NEC Article 725 Class 1, they may share the conduit if functionally related. If they are NEC Article 725 Class 2, then separation is required.
