Overload relays prevent motors from being damaged due to overcurrent problems by supervising the phase currents. Thermal variants utilize a bimetallic strip, while electronic versions utilize solid-state trip points (0.4-1.2x rated current) sensors. Along with contactors, they are compliant with IEC 60947-4-1 and possess manual/automatic reset for pumps, compressors, and machine tools so that the motors are not burnt out.