Solid State Overload Relay - 3RB range 3RB30 and 3RB31 solid-state overload relays up to 80 A with internal power supply have been designed for current-sensitive protection of loads with normal and heavy starting against excessive temperature rises due to overload, phase unbalance or phase failure Switch position indicator and test function Trip class setting/internal ground-fault detection Selector switch for manual/automatic reset Class 10 and Class 20 Direct mounting PTB 09 ATEX 3001 Ex II (2) GD Approvals CE, UL, CSA Electronic Overload Relays The 3RB2 range of Solid State Electronic overloads can be connected directly to Siemens SIRIUS contactors to provide accurate motor overload protection with enhanced single phase sensitivity,Application: Protection of 3 phase AC motors in sinusoidal 50/60Hz network. These relays are not suitable for the protection of single phase or DC loads,Select according to motor full load current and contactor frame size e,g. S00