Sigma Electronic Type Compact Circuit Breakers provide protection against overload and short-circuit currents via an electronic control unit. They offer faster detection and tripping compared to thermal-magnetic compact circuit breakers in cases of overload and short-circuit, and their thermal-magnetic setting ranges are wider. They are unaffected by ambient temperatures up to 60°C. Electronic compact circuit breakers measure the current in each phase separately.

Sigma Electronic Compact Circuit Breakers start measuring above 30A. An alarm signal activates when the current reaches 95% of the rated current.  It indicates that the switch is close to its nominal current value. When it reaches 105% of the nominal current, the overcurrent signal activates. It indicates that the switch has reached its opening limit.

Model-based product versions with short-circuit delay and earth fault protection features (LSIG protected) provide superior protection.