What this solid-state overload relay does
The Siemens 3RB3036-1UB0-ZX95 is a SIRIUS solid-state overload relay — it protects motors against overcurrent by simulating the thermal characteristic of the motor winding, then tripping a signaling contact when the thermal model reaches the trip threshold. Rated thermal current is 50 A at 690 V, with the same 50 A continuous rating at both 480 V and 600 V — no derating needed across common North American line voltages.
Fastens directly onto the contactor (contactor mounting) — no separate DIN-rail footprint required, so it occupies the same vertical slot as the contactor itself. Size S2 frame: 55 mm wide, 99 mm high, 104 mm deep — fits the standard S2 contactor interface and leaves room for main-circuit wiring with screw-type terminals accepting 1x 50 mm² or 2x 35 mm² stranded.
Signaling contact ratings and the tripped message
The integrated auxiliary switch provides a signaling contact that changes state when the relay trips, carrying 2 A at 24 V, 4 A at 120 V, or 3 A at 230 V — enough to drive a PLC input or a pilot light directly.