This series of thermal overload relay can be used in the circuit of 50Hz or 60Hz, rated insulation voltage 660V, rated current 0.1-140A for protecting the phase break when the electric motor is overload.
The relay has different mechanism and temperature compensation & can be pluged in OLC1-D series AC contactor. It is the most advanced thermal relay in the nineties in the world. The products comply with IEC 60947-5.