Star-delta contactor assembly — what ships in the box
The 3RA2445-8XE32-1NB3: This is a pre-assembled SIRIUS star-delta starter, not a bare contactor. The package includes three contactors: two 3RT2045-1NB30 units (one with the -0CC0 variant that includes a varistor surge suppressor) and one 3RT2036-1NB30, plus the 3RA2943-2C RS assembly kit. The varistor across the coil suppresses voltage spikes during de-energisation — saves adding a separate suppressor at the panel level.
Power ratings and duty — what 75 kW at 400 V means on the line
The maximum operating voltage is 690 V AC-3. These are the numbers that govern the motor FLC it can handle — the 75 kW figure at 400 V is the one most panel builders will size against for a 400 V distribution system. The magnet coil pulls 154 W closing power at DC, with a control voltage range of 20 to 33 V DC. Coil terminals are screw-type, same as the main and auxiliary circuits — consistent termination throughout, no mix of spring and screw. Mechanical life is rated at 10 million operating cycles typical for the contactor. The maximum switching rate in AC-3 is 1,000 operations per hour — relevant if this starter is cycling a load that fast (most pump/fan applications run far below that).
Mounting and panel fit — DIN rail or screw, with rotation flexibility
Mounts on 35 mm DIN rail via the snap-on feature, or can be screw-fastened. This matters when the panel layout forces an odd orientation — most contactors lock you into one plane. Dimensions are 180 mm high, 220 mm wide, 244 mm deep. The depth is the dimension that sticks out from the DIN rail — at 244 mm, check your enclosure depth before committing. Clearance requirements: 10 mm upwards, forwards, downwards, and to the side; 0 mm backwards (sits flush against the mounting surface).