Well I measured amps & volts. Remember the two legs of 240V circuit in US wiring are out of phase so to read current you need to clamp just one conductor.
but I have the rigs connected to a PDU using C14 to C13 cables and I doubt anyone makes an adapter so I modified one power cable which I use for testing only.
Did you take power factor into account when you measured volts and amps separately? I'm running at PF about .9 so maybe that caused the difference if you measured different ways for 120 vs 240.
