Star-delta starter assembly, 45 kW at 400 V
The Siemens 3RA2436-8XE32-1NB3 is a factory-assembled SIRIUS contactor assembly for star-delta (wye-delta) motor starting, rated 45 kW at 400 V. It ships with three contactors: two 3RT2036-1NB30 (one with surge suppressor -0CC0 variant) and one 3RT2028-1BB40, plus the RS assembly kit 3RA2933-2C. The 45 kW rating at 400 V means this assembly handles the transition current peak during the star-to-delta switch for motors up to that power — the contactors are sized for the line and phase currents in a star-delta topology, not for direct-on-line duty.
Mounting and panel fit — 177.5 x 142 x 223 mm
The assembly measures 177.5 mm wide, 142 mm high, and 223 mm deep — the depth is the dimension that matters for enclosure depth clearance. Clearance requirements: 10 mm upwards, forwards, downwards, and to the side; zero backwards clearance needed.
Wiring terminals and conductor sizes
The magnet coil uses screw-type terminals as well. For the star-delta configuration, the required upstream fusing at assignment type 2 is 80 A gG NH 3NA, DIAZED 5SB, or NEOZED 5SE.
Coil and control details
The magnet coil operates on DC 20 to 33 V, with closing power 28 W and holding power 4 W. The surge suppressor is built in with a varistor. No auxiliary switch extension and no bus communication — this is a standalone power assembly.