Siemens 3RB1253-0FG10 Overload Relay, 50-205 A, Discontinued

The 3RB1253-0FG10: The 50-205 A range covers medium to large motor loads — think 30-100 kW induction motors at 400 V. Class 5-30 F means the trip delay is adjustable from fast (5 seconds) to slow (30 seconds) for Class F (full motor protection), matching typical motor start curves. Size S6 is a physical frame; it mounts individually or via continuous busbar connection, common in MCC buckets or standalone enclosures. The AC 110-120 V control coil is standard for North American panel voltages; verify your control transformer taps.