how to measure 3-phase voltage on 3 phase Square D panel going to each phase A phase to neutral measure B phase to neutral C phase to neutral then measure phase to phase this is a 3 Phase balance system known as open Delta this is a 120-240 volts 3 phase system you will have 120 volts on each leg 240 volts phase to phase on B phase ( high leg) 208 volts to neutral Thanks for watching! David [email protected] Follow me on Facebook: / david-jones-ac-101070258275291