SIRIUS S3 Power Contactor for Motor Loads
Its AC-3 rating of 37 kW at 500 V and 18.6 kW at 690 V defines the motor load it can handle under typical starting and running conditions — the rating that governs real-world sizing, not the higher AC-1 resistive figure. The 24 VDC coil with a pick-up threshold of 0.7x rated value (about 16.8 V) and dropout below that ensures reliable pull-in even on a sagging control supply.
Side-by-side mounting is permitted, so multiple contactors can be ganged without spacing blocks. The envelope is 176 mm high by 70 mm wide by 152 mm deep.
Main circuit terminals are screw-type, accepting a wide range of conductor sizes: solid or stranded 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and up to 2x (0.75 to 4 mm²) for control wiring. The main power terminals accept 2x (10 to 50 mm²) stranded, with a maximum of 35 mm² for AC-1 rated connections. This range covers most panel wiring from control-circuit signal wires up to motor feeder cables.