What this MCCB carries
The Siemens 3VA2340-6JP32-0AG0 is a SENTRON molded case circuit breaker rated for 400 A continuous current at 40 °C, with no derating needed up to 50 °C — it holds 400 A solid through that range. At 55 °C it's still good for 375 A, and at 70 °C it delivers 300 A. That thermal curve matters when the breaker sits in a crowded turbine cabinet or a hot switchgear lineup where ambient runs high. Breaking capacity climbs with the voltage drop: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V. For most low-voltage distribution in wind or industrial plants, that 187 kA at 415 V is the number that governs selectivity and SCCR coordination downstream. It's a 3-pole unit, designed for line protection, with a built-in communication function for remote monitoring or integration into a BMS or SCADA system. The trip indicator gives a local visual when the breaker has opened on fault — saves chasing a downstream short blind.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. That 110 mm depth is the key fit number for shallow enclosures — measure your backpan-to-door clearance before ordering. The 138 mm width means it occupies three standard 45 mm pole spaces on a DIN rail or bolted bus. The basic switch variant is 3VA2340-6JP32-0AA0; the -0AG0 adds a 1 auxiliary switch plus 1 trip alarm switch (HP type). No undervoltage release or ground-fault monitoring on this variant — those are separate order-code options if your spec requires them.
Thermal and electrical endurance
Maximum power loss is 96 W at rated current. That's the heat you need to vent from the enclosure — plan for it in the thermal budget, especially if the breaker is grouped with other high-current devices. Operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. That -25 °C floor means it's fine for unheated turbine nacelles or outdoor substations in most temperate climates, but if your site sees -30 °C regularly, you need the cold-rated variant.