The Siemens 3RB1246-1QB00-0FM0 is a solid-state overload relay that combines motor overload protection with integrated thermistor monitoring and ground-fault detection in a single DIN-rail mountable package. It is rated for a current range of 6.3 to 25 A, operates on a DC 24 V control supply, and uses an external summation current transformer to monitor ground faults. The relay provides two independent signal paths: one NO/NC contact set for overcurrent and thermistor faults, and a separate NO/NC set for ground-fault events, both configured as monostable outputs.
The DC 24 V control voltage is common in modern PLC-driven panels, and the separate ground-fault output allows direct wiring to a safety PLC or alarm annunciator without additional interposing relays.