The Struthers & Dunn relay is used in the OpenEVSE "Advanced Series" products. It features a 12v DC coil which is actuated from the power supply on the controller. This allows the relay to function over a very wide range from 90v - 264v AC.
Struthers-Dunn Model - 450BXX50-12
50A Continuous Current
-55°C to 105°C Operating Temperature
Available with or without a "Advanced Series" wiring harness for OpenEVSE v5 Controller