Lighting maintenance, especially with 277, is one of those areas where the rulebook clashes with reality.
Even under ideal circumstances (where you can kill power to the fixture without leaving everyone in the dark), the maintenance guy or electrician is sure to have a fight with management over flipping the switch.
Making things worse are the ways we design offices. In the old days (just 5 years ago), offices were deliberately designed so that everything was off one breaker, and there were no local area switches. Or, everything was routed through a contactor, making it a real puzzle as to which breaker was the right one; heaven help you if that was also the circuit that powered the contactor!
Now we have 'energy codes' that are introducing automatic switches into the mix. (Gee, it WAS off!). The EPACT rules also often result in each fixture having two circuits in it (which one has the bad ballast on it). Some recent code rules also want you to put ALL of the circuits that share a neutral on a common-trip or handle-tied breaker- so we;re back to working in the dark again.
They've come out with 'disconnects' for ballasts, yet unresolved is who supplies them, and what they look like. The result is that you're likely to wind up changing them every time you change the ballast - thus presenting yourself with the 'working hot' issue all over again.
Yet, one point cannot be stressed enough. 277 IS DIFFERENT from 120, or even 240. 277 is just enough to pass the 'I can't let go' threshold. Therefore, one DOES NOT work 277 hot - especially without proper gloves, etc. That little wire will kill you as quick as a big wire will. Plus, the secretary will really get upset when your body lands on her desk.
Management has to get this through their heads. Nearly every lighting maintenance fatality involves 277.
