It sounds like it would be okay, if in fact the insulation rating is the same.
Without seeing the installation, it appears that it would be in compliance.
Check with the local electrical inspection department for a final interpretation.
12-3032 Conductors in Boxes, Cabinets, or Fittings
(1) Conductors that are connected to different power or distribution transformers or other different sources of voltage shall not be installed in the same box, cabinet, or fitting unless:
(a) A barrier of sheet steel not less than 1.3 mm thick or a flame-retardant nonmetallic insulating material not less than 1.6 mm in thickness is used to divide the space into separate compartments for the conductors of each system; or
(b) The conductors are used for the supply and/or control of remote devices and are insulated for at least the same voltage as that of the circuit having the highest voltage and none of the conductors of the circuits of lower voltages is directly connected to a lighting branch circuit; or
(c) The conductors are used for the supply of a double-throw switch in an emergency lighting system.
(2) Where a barrier is used, it shall be fastened rigidly to the box, cabinet, or fitting, or a device assuring positive separation of the conductors shall be used.
Rationale and Intent for Rule 12-3032. We intend to prevent a condition in which conductors of one power source may become crossed with conductors from a different source and impress another voltage on the circuit, when they are installed in the same box, cabinet, or fitting. Conductors from different sources are allowed in the same box, cabinet, or fitting if they are separated by a barrier of 0.051 inch (1.3 mm); or the conductors are used for the supply and/or control of remote devices and are insulated for the highest voltage in the enclosure (the low-voltage conductors cannot be connected to a lighting branch circuit); or are used for the supply of a double-throw switch in an emergency lighting system.
Tony Moscioni
Electrical Inspector
Electrical Safety Authority
