The Allen-Bradley 140G-KTH3-D40 trip unit is a factory-supplied electronic trip unit from the 140G frame K circuit breaker series, and it is designed to provide short-circuit protection, thermal protection, and overload protection for a wide range of applications. This trip unit offers the true RMS (current) sensing capability, in addition to the ability for users to customize the protection curve to suit specific application needs. The 140G-KTH3-D40 trip unit has a continuous current rating of 400 Amps, and a maximum operating voltage rating of 600 Volts AC. It has a 3-pole wiring design that makes it suitable for most industrial 3-phase applications, and it is supplied for standard end-cap line and load end terminals for easy installation. The 140G-KTH3-D40 trip unit offers highly advanced thermal protection by detecting the current flow and modeling the heat generated by the current, thus allowing the users to customize the breaker’s thermal trip behavior to suit application needs. 

The 140G-KTH3-D40 trip unit also has additional advanced functionalities like the long-time delay overcurrent protection setting, short-time delay short-circuit protection, and the instantaneous trip short-circuit protection. The 140G-KTH3-D40 trip unit offers a long-time delay setting range of 3 to 18 seconds, and an adjustable magnetic/short-circuit setting with a current range from 240 to 4000 Amps (the breaker’s magnetic trip rating). This trip unit, like every 140G electronic trip unit, has a 100% continuous load rating, and it can work with a temperature between -25 to 70 degrees Celsius. The 140G-KTH3-D40 trip unit is UL, CCC, CE, and CSA certified. It is installed on a DIN rail, and it has approximate mounting dimensions of 140 x 108.5 x 205 millimeters.