Single Phase PS to 3-Phase System

Discussion in 'General Electronics Chat' started by AutoNub, Feb 16, 2012.

  1. AutoNub

    Thread Starter Member

    Oct 14, 2011
    I'm just curious, but what exactly would happen if you were to connect a single phase input power supply to a 3-phase source? I suspect the single phase power supply, being rated for a smaller voltage (V rather than V*1.732), would simply overheat and ultimately fail. Does anyone know exactly? Thanks!
  2. BSomer


    Dec 28, 2011
    That would depend on the voltage requirements of your single phase power supply and which 3 phase system you are attempting to connect it to.

    120/240 single phase with neutral
    120/208 3 phase with neutral
    277/480 3 phase with neutral
    120/240 3 phase ungrounded

    There are a couple more out there still in use in the US. If you were to connect a power supply that was 240VAC single phase to a 208VAC 3 phase system, the power supply may still work, though it would be derated some. However, if you connected it to the 480VAC system it would immediately fail, BIG!