Heres a curly one. Surprisingly difficult to obtain the sort of engineering level documentation you'd require to answer this one. Probably almost need schematics - but I'd be happy enough with an informed (from manufacturer) blanket engineering based statement.
As we know one of a UPS's main functions is to protect equipment plugged into its power OUTPUT(s) from dangerous stuff coming in to its INPUT(s). That bit I'm fine with of course.
However, as a general thing, are consumer grade - SMB grade equipments, say 5KVA or less, cross output isolated or protected in any way? Or, as I suspect in general, are the outputs essentially bus-barred to each other?
The reason I even ask this is that I received a request from a customer to connect his PABX phone system to his main servers UPS. Seems a reasonable request on the face of it. He recently...