MCCB for line protection with communication
The Siemens SENTRON 3VA2340-5JQ42-0HH0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying 400 A continuously at 40 °C without derating. The 187 kA breaking capacity at 240 V (121 kA at 415 V, 75.6 kA at 500 V, 7.5 kA at 690 V) gives it the interrupting capability for high-fault industrial feeders — think transformer secondaries, main distribution panels, or large motor control centers where available fault current is substantial. The unit includes an electronic trip unit adjustable between 80 A and 400 A full-scale, with a trip indicator and undervoltage trigger, so you can coordinate selectively downstream without oversizing.
Thermal derating and power loss
The breaker holds 400 A up to 50 °C ambient; above that it derates linearly to 300 A at 70 °C. Maximum power loss is 96 W — relevant for enclosure heat rise calculations when grouping multiple breakers in a panel. The dimensions (248 mm height, 184 mm width, 110 mm depth) fit standard Siemens SENTRON mounting patterns; the 4-pole width matches the 184 mm footprint expected for a 400 A frame.
Auxiliary and release options
This variant ships with two auxiliary switches plus one trip alarm switch (HQ design), and a shunt trip release (STL) for remote tripping. The basic switch assembly is order code 3VA2340-5JQ42-0AA0, so if you need a replacement switch block, that's the spare. Communication function is built in — no separate module required for status feedback to a PLC or SCADA system.