The S281-K0.5W is a motor circuit breaker manufactured by ABB. It is a type S 1000 series breaker and is designed for rapid and reliable protection of medium voltage motors and other starting devices, when used in conjunction with the S272 coordinated release system. The trip unit is factory wired, allowing it to be installed in applications up to 690 Volts AC, and has a short time trip setting of 0.5 to 6 seconds. The wide pre-selection range of 3 to 50A makes the breaker reliable and flexible in motor circuit protection. In terms of design, the S281-K0.5W is a UL489-certified, double insulated, space-saving, combined panel-type, padlockable and screw-type terminal connection device.