645.10
An approved means shall be provided to disconnect power
to all electronic equipment in the information technology
equipment room or in designated zones within the room.
There shall also be a similar approved means to disconnect
the power to all dedicated HVAC systems serving the room
or designated zones and shall cause all required tire/smoke
dampers to close.
Be sure you need to do this at all. Many new data centers do not use leniencies in 645 anymore so EPO's are not required.
I would say it depends how you interpret the word "equipment" in this sentence "An approved means shall be provided to disconnect power to all electronic equipment in the information technology equipment room".
Article 100 defines equipment as: "A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as part of, or in connection with, and electrical installation."
My interpretation is that yes, lights and receptacles are required to be disconnected under the wording of 645. But Ron's point stands. Are you sure you even need an EPO at all?
To get slightly off topic, but not really.....must there be a single EPO for the server/IT room for electronic equipment, or can there be two such shutoffs (dual power available)? If only one is permitted, a contactor may be used to provide simultaneous (one operation) shutoff. I cannot find anything in Art. 645 that prohibits a second EPO (not just for HVAC, but for electrical supply panels for the electronic equipment). If two separate EPOs are permitted for emergency shut off of all electronic equipment, do they need to be grouped or may they be remote from each other?