3-Phase Voltage Monitor/190-240V. The 350 Is A Heavy-Duty Voltage Monitor. This Product Should Be Used When High Current Relays or Dual Contacts Are Required, or 480V Controls Are Used. Since The 350 Uses Heavy-Duty Relays, It Comes In Fixed Voltage Range Models Rather Than A Dual Autoranging Version Like The Model 250. Has A 15A General Purpose Contact. The 350-400 Provides A SPDT (Form C) Relay Rated to Switch Up to 600V, Allowing The Use Of 480V Controls, Eliminating The Need For A Control Power Transfo