Q. Can a 2-pole snap switch be used to switch a 277V and 120V circuit?

A. No. A multi-pole, general-use snap switch is not permitted to be fed by more than a single circuit unless the switch [404.8(C)]:

  • Is listed and marked as a 2-circuit or 3-circuit switch, or
  • The voltage rating of the switch is not less than the nominal line-to-line voltage of the two circuits supplying the switch.