In the plant that I work in we are changing all of the drop lights that people use to check bin levels, look in mixers etc to plug ins, that way they can unplug them before changing the bulb. That way we (electricains) don't have to do it for them.
It really doesn't matter what you are doing, it should be done with the power OFF, unless the power is required to be on for an adjustment. I can't quote all of the legalese, but that is the gist of the OSHA requirement.
The power not only has to be off, it needs to be locked out too. Trust me, that 277 will hurt even worse if you are holding the wire in your fingers and someone energizes the circuit.
You might think that I am kidding, but I recently changed some bulbs in the plant managers office, our compnay requires two individual locks be placed, a form filled out and then the work can start.
Not a bad system but I somedays think it's overkill for light bulbs.
