Star-delta contactor assembly for 55 kW motors
The 3RA2437-8XF32-1AG2: It ships with three contactors: two 3RT2037-1AG20 units and one 3RT2035-1AG20, plus the RS assembly kit 3RA2933-2BB1. All main, auxiliary, and control circuit connections use screw-type terminals, and the contactor size is S2, matching the standard SIRIUS footprint for this power class.
Mounting, clearances, and environmental limits
The assembly measures 177.5 mm wide, 142 mm high, and 223 mm deep. It fastens via screw fixing, not DIN-rail clip, so panel layout must account for drill points. Minimum clearance around the unit: 10 mm upwards, forwards, downwards, and to the side; 0 mm backwards. The assembly withstands vibration at 18.5g / 5 ms and 11.6g / 10 ms under AC excitation.
Fuse coordination and conductor sizing
For type 2 coordination, the required backup fuse is 125 A using gG NH (3NA), DIAZED (5SB), or NEOZED (5SE) types. The main circuit accepts solid conductors: 2x (1 to 35 mm²) and 1x (1 to 50 mm²). Rated switching frequency at AC-3 is 700 operations per hour maximum, with a mechanical life of 10 million operations typical.