What this MCCB delivers — and what the ratings mean for your panel
The Siemens SENTRON 3VA2340-6JQ32-0AJ0 is a 3-pole molded case circuit breaker rated 400 A at 40 °C, designed for line protection in distribution panels and motor control centers. Its current setting range spans 600 A to 4 000 A, so it handles main feeder or large subfeed applications where you need adjustable trip coordination downstream of a transformer or upstream of branch breakers. Breaking capacity is the headline selector here: 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. At 415 V — common for industrial distribution in IEC markets — the 187 kA rating means this breaker clears high-fault scenarios without cascading upstream, which simplifies selective coordination studies and lets you keep downstream breakers at lower ratings. Thermal derating is published per degree: it holds 400 A flat through 50 °C, then steps down to 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. If your panel ambient runs above 50 °C — common in enclosed switchgear or hot-climate installations — factor the 55 °C derate into your load budget. The breaker includes a communication function and a trip indicator, which simplifies integration with a BMS or SCADA system for remote status and fault annunciation. Auxiliary switch configuration is 2 auxiliary switches plus 1 trip alarm switch HP, giving you three separate signal paths for control logic and alarm annunciation.
Sourcing and lifecycle — active, quoted to order
The basic switch variant 3VA2340-6JQ32-0AA0 shares the same frame and trip unit; the -0AJ0 suffix adds the auxiliary switch and trip alarm configuration listed above. If your BOM calls for the base switch without auxiliaries, the -0AA0 is the direct drop-in.
Panel fit and environmental limits
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 110 mm depth fits standard MCCB mounting footprints in distribution panels; verify the busbar and lug kit clearance against your enclosure depth before ordering. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 96 W — account for this in enclosed panel thermal calculations, especially when grouping multiple breakers.