Q Can an emergency power supply occupy the same wire-way with a standard circuit? I have a suspended fluorescent lighting fixture.

The luminaire has a single wireway, which is already occupied by the standard power supply. Can you have the wiring from another source (emergency power in this case) in the same wireway as the standard circuit?

A In general, emergency wiring must be kept separate from other wiring. This rule is found in Section 700-9(b). There are four cases given in this section where such separation requirements are relaxed somewhat. However, none of the special cases applies to your situation. The two sources could be present in the same fixture, but the use of a fixture as a common raceway for emergency and other circuits is not allowed. Separations are critical to the reliability of emergency systems.