SENTRON 3VA2340-6JQ32-0AB0 — 4000 A MCCB for Line Protection
The Siemens SENTRON 3VA2340-6JQ32-0AB0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection, with an adjustable current range from 600 A minimum to 4000 A maximum. It carries a full-scale value of 400 A and an initial trip setting of 80 A, meaning the breaker is field-adjustable to protect feeders or large loads within that band. Interrupting capacity reaches 242 kA at 240 V and 187 kA at 415 V, dropping to 121 kA at 500 V and 7.5 kA at 690 V — the 690 V figure is the limiting case for high-voltage industrial systems, so verify the available fault current at your service voltage against these ratings.
Thermal Derating and Power Loss
Current-carrying capacity is temperature-dependent: the breaker is rated 400 A at ambient temperatures up to 50 °C, then derates to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. Maximum power loss is 96 W. For a panel builder, this means enclosure ventilation or forced cooling may be needed if the breaker is loaded near its full rating in a warm cabinet — the derating curve is the selection guide, not the 400 A headline.
Dimensions and Mounting
The MCCB measures 110 mm deep, 138 mm wide, and 248 mm high. It is a panel-mount device — no DIN-rail clip. The 3-pole footprint is standard for this class; verify cutout dimensions against the existing switchboard or enclosure gland plate before ordering.