MCCB for line protection — 200 A, 4-pole, TM240 release
The Siemens SENTRON 3VA1220-4EF42-0AG0 is a 4-pole molded case circuit breaker rated for 200 A continuous current (Iu) at 40 °C, with a TM240 thermal-magnetic overcurrent release. Interrupting ratings span 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V — covering most industrial low-voltage fault scenarios without needing an upstream current-limiting fuse. Front protection is IP40, suitable for enclosed panel mounting.
Thermal derating and endurance
Rated continuous current holds at 200 A from 40 °C through 50 °C, then derates linearly to 176 A at 70 °C. For panels with elevated ambient temperatures, the 55 °C rating of 194 A and 60 °C rating of 188 A give clear headroom for sizing. Mechanical latching endurance is rated at 15,000 operations — typical for a fixed-mounted MCCB in a distribution board where switching cycles are infrequent.