Can the 0-10 Volt Wires Run in the Same Conduit as the High Voltage
The National Electrical Code has been adopted in all states. However local by laws may modify t and some states may operate on earlier versions than the 2002 Version quoted here. In all cases “the authority who has jurisdiction” meaning “the electrical inspector” may override or improve on any point in the NEC if he so wishes.
NEC 300.3 (c) (1):
“Conductors of circuits rated 600 volts, nominal or less, ac circuits, and dc circuits shall be permitted to occupy the same equipment wiring enclosure, cable, or raceway. All conductors shall have an insulation rating equal to at least the maximum circuit voltage applied to any conductor within the enclosure, cable or raceway. “
The dimmed (0-10v) signal is usually not affected by being located near a line voltage circuit. As far as our equipment is concerned, the 0-10v signal conductors and the line voltage (120/277/480V) circuits may usually occupy the same conduit. As long as the point above regarding the insulation of the conductors is covered.
In other words, the line voltage and low voltage outputs from the Micro Panel do not need to occupy separate conduits or enclosures. (Unless otherwise specified by local codes, the “authority having jurisdiction or is stated on the cut sheet for the ballast.”)
Ordinary #12 THHN or even down to #18 THHN may be used between the (0-10v dimming outputs and ballast. There is no special requirement of shielding or twisted pair wire.
I some situations particularly for some pendant fixtures the dimming control wires are located at the other end of the fixture and running two #18 wires in a low voltage cable with 300v insulation may be the desired way of doing it.
That being said LC&D recommends that the low voltage wires are always run separately from the high voltage 1 foot apart. Also check the specs of the ballast, some ballast requires that the 0-10v wires are run separately.