Line protection MCCB with communication — 400 A frame, 65 kA at 415 V
The Siemens 3VA2340-6JQ32-0JL0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in main distribution panels. It carries a 400 A continuous rating at 40 °C and an adjustable overcurrent trip range from 600 A to 4 000 A, giving the site engineer selectivity headroom downstream. The interrupting capacity hits 242 kA at 240 V and 187 kA at 415 V — enough to handle high-fault utility feeds without cascading upstream. Three-pole construction, 248 mm tall, 138 mm wide, 110 mm deep. The depth is the dimension that matters most in retrofit panels — at 110 mm it fits standard MCCB compartments without gland-plate interference.
Thermal derating and trip unit
Rated 400 A from 40 °C through 50 °C ambient. Above that, derate linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, 300 A at 70 °C. If the panel internal ambient runs hot — common in compact switchboards — the 55 °C derating to 375 A is the figure to budget against. Electronic trip unit with LSIG functions: long-time (L), short-time (S), instantaneous (I), and ground-fault (G). Initial setting at 80 A, full-scale 400 A. Trip indicator and voltage trigger are both present — useful for remote fault annunciation via the communication function.
Auxiliary switches and shunt trip
Factory-fitted with 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ configuration). Also includes a shunt trip (STL) for remote opening via a control signal. The auxiliary switch count is enough to report breaker position to a PLC, interlock a downstream contactor, and drive a panel lamp — all from one device. The supplied basic switch variant is 3VA2340-6JQ32-0AA0 — the base MCCB without the communication module. This -0JL0 suffix adds the communication function, so if the BOM calls for a breaker that talks to a building management system, this is the variant.