The CR1BM33M21 is a TeSys F magnetic contactor from Schneider Electric, a bistable (latching) 3-pole device rated for 1000 A in AC-3 duty at 440 V — that's the motor-switching rating, so it handles heavy induction motor loads up to that current.
Coil and control circuit — the bistable latching logic
This is a latching contactor: the coil draws power only during the switching transition, then holds its state magnetically. Control voltage is 220-230 V AC, 50-400 Hz. Latching consumption hits 1100-1650 VA depending on frequency; unlatching is lower, 100-165 VA. The coil operates between 85% and 110% of rated voltage for both latching and unlatching. Operating time is 100-150 ms to latch, 20-40 ms to unlatch.
Breaking capacity and fault clearance
Rated breaking capacity varies with voltage: 10000 A at 220-440 V, 8000 A at 600-690 V, 4000 A at 1000 V. The making capacity (Irms) is 10000 A. For fault protection, the manufacturer specifies 1200 A aM, gG, or BS88 fuses on the power circuit. This gives the panel builder a clear coordination target for upstream protection.
Thermal performance and operating conditions
Power dissipation per pole is 280 W in AC-1 (resistive) and 180 W in AC-3 (motor) duty — relevant for enclosure heat rise calculations. Ambient operating range is -15 to 70 °C. Mechanical durability is rated at 1,000,000 cycles, with a maximum operating rate of 120 cycles per minute at 40 °C.
Insulation coordination and standards compliance
Rated insulation voltage (Ui) for the control circuit is 1000 V per BS 775, IEC 60158-1, and IEC 60947-4, and 1500 V per VDE 0110 group C. The power circuit is rated for 1000 V AC and 1000 V DC. The contactor carries protective treatment TH (tropicalized, humidity-resistant).