Siemens 3TD2000-1BB4 Three Phase Overload Relay

Siemens 3TD2000-1BB4 is a compact, three-pole reversing contactor (Size 00) with a 24 V DC coil that enables bidirectional control of a three-phase motor. Designed for motor-control applications at up to 400 V AC, it handles typical loads up to about 4 kW at 400 V and reverses motor direction by interchanging supply lines in the control circuit. As part of Siemens' 3TD family, this reversing assembly features a small footprint for easy panel integration and straightforward wiring for dual-direction operation in compact control cabinets. It's a reversing contactor rather than a standalone overload relay, so in a complete protection scheme it's typically used in conjunction with a matching overload device from Siemens to protect the motor from overload conditions. The 3TD2000-1BB4 configuration is commonly seen in industrial applications such as conveyors, pumps, and fans where reliable, bidirectional motor operation is required.