Hi Don, welcome to the forum. :thumbup:
I cna't speak for your power supplies specifically, but I have used and installed many Kinoton Film projectors that are designed for 240v line to neutral on a standard 240 volt line to line circuit with no problems whatsoever. (Kinoton officially ok's such a connection.)
Unless you power supplies have some filtering or surge suppression components that connect neutral to ground (or chassis) that are rated less than the 240v they might see, there should (I'd say comfortably will) be no problem connecting them 240 line-to-line for testing at least.
If you use a 277 to 240 step down transformer, you will have too low of voltage on the secondary due to the primary being fed only 240 volts..if you are giving the correct voltages coming from your intended branch circuit in your OP. Or, use a 480v to 240v step down transformer and ground/connect one leg of the 240v secondary to the primary side neutral to give you a neutral for your testing.
But I feel that if the voltage you have coming from your branch circuit is 240 line to line you are wasting money with an additional transformer.
I cna't speak for your power supplies specifically, but I have used and installed many Kinoton Film projectors that are designed for 240v line to neutral on a standard 240 volt line to line circuit with no problems whatsoever. (Kinoton officially ok's such a connection.)
Unless you power supplies have some filtering or surge suppression components that connect neutral to ground (or chassis) that are rated less than the 240v they might see, there should (I'd say comfortably will) be no problem connecting them 240 line-to-line for testing at least.
If you use a 277 to 240 step down transformer, you will have too low of voltage on the secondary due to the primary being fed only 240 volts..if you are giving the correct voltages coming from your intended branch circuit in your OP. Or, use a 480v to 240v step down transformer and ground/connect one leg of the 240v secondary to the primary side neutral to give you a neutral for your testing.
But I feel that if the voltage you have coming from your branch circuit is 240 line to line you are wasting money with an additional transformer.
