TeSys K overload relays are designed to be used with TeSys K contactors to make a motor starter. These differential thermal overload relays detect over currents in the lines to the motor. When an overcurrent is detected the overload relay working with the contactor will disconnect the power to the motor. This will minimize the damage to the motor windings. This overload relay has an adjustable trip current rating of 2.6 to 3.7 amperes. – LR2K0310