RP1A & RP1B Single Phase Solid State Relay Carlo Gavazzi RP1A & RP1B Single Phase Solid State Relays are PCB mount AC solid-state relays. These relays feature thru-hole and surface mount configurations, instant-on, and a rated operational voltage of up to 480VACRMS. Flexible encapsulation enables a long operating life. Carlo Gavazzi RP1A & RP1B Single Phase Solid State Relays are suitable for a variety of applications including