Thermal overload relay for motor protection
The ABB TA75DU25 is a thermal overload relay from the A-Line family, designed as an economic electromechanical protection device for the main circuit. It provides reliable and fast protection for motors in the event of overload or phase failure, with a Trip Class 10A rating. The device includes temperature compensation to maintain accurate trip timing across ambient temperature shifts, plus a trip-free mechanism that prevents the relay from being reset while an overload condition persists. A stop and test function aids commissioning and fault isolation.
Reset and contact configuration
Automatic or manual reset is selectable via a front-panel switch, giving the panel builder flexibility: auto reset for remote or unattended installations, manual reset for local fault investigation. The trip indication provides a visual status at the relay face. The relay carries a normally closed (NC) trip contact and a normally open (NO) signal contact. The NC contact breaks the motor contactor coil circuit on a trip; the NO contact can drive a remote alarm or PLC input.