Siemens 3VA2340-5JQ42-0CC0 — 400 A SENTRON MCCB, 4-Pole, 187 kA SCCR
The Siemens SENTRON 3VA2340-5JQ42-0CC0 is a 4-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in distribution panels and switchgear assemblies. Its interrupting capacity hits 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — so it handles high-fault utility feeds and transformer secondaries without cascading upstream. The unit carries an undervoltage release (UVR) and two built-in auxiliary switches HQ, plus a communication function for integration with plant monitoring systems. At 98.5 W maximum power loss, factor that into enclosure thermal calculations.
Breaking capacity and selectivity headroom
The 187 kA SCCR at 240 V is the standout figure — this breaker clears faults at that level without needing a current-limiting fuse upstream. At 415/440 V the 121 kA rating still covers most industrial service-entrance and sub-distribution scenarios. The drop to 75.6 kA at 500 V and 7.5 kA at 690 V means at 690 V you'll need to verify available fault current against the lower limit; if the installation exceeds 7.5 kA, a current-limiting upstream device or a higher-rated frame is required. The 400 A continuous rating holds flat from 40 °C through 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 — a 25% drop at the top end, so a panel running hot needs the thermal curve consulted before loading.
Panel integration and wiring
Dimensions: 248 mm height, 184 mm width, 110 mm depth (9.76 × 7.24 × 4.33 in). Four-pole frame with line-side and load-side lugs — 80 A initial trip setting, 400 A full-scale value. The undervoltage release (UVR) is wired to a separate control circuit; if the control voltage drops, the UVR trips the breaker open. Two HQ auxiliary switches provide status feedback to a PLC or annunciator panel. The communication function allows remote monitoring and control via the SENTRON bus system — no separate gateway module needed for basic data exchange. Operating temperature range -25 °C to 70 °C; storage range -40 °C to 80 °C.