The circuit breaker for transformer protection MS132-0.4T is a compact 45 mm width device designed to protect control transformers on the primary side. This device has a rated operational current of I.e. = 0.4 A. It allows fuse-less protection against overload and short-circuit. The short-circuit current setting is fixed to 20 times the rated operational current to handle the high inrush current generated by transformers. The device allows manually connect and disconnect the transformer from the mains thanks of its built-in disconnection function. The circuit breaker for transformer protection offers a rated service short-circuit breaking capacity of Ics = 100 kA at 400 VAC and a trip class 10. Further features are temperature compensation, trip-free mechanism, rotary handle with a clear switch position indication and short circuit trip indicator. The handle is lockable to protect against unauthorized changes. Auxiliary contacts, signaling contacts, under voltage releases, shunt trips, power in-feed blocks and terminal spacers are available as accessory.