What this breaker is and what drives the choice
The Siemens 3VA2340-7KP32-0AL0 is a 3-pole SENTRON molded case circuit breaker (MCCB) carrying an ETU850 electronic trip unit. Its adjustable overload range — 80 A minimum up to 640 A maximum — means it can be set to protect a transformer secondary, a bus riser, or a large motor feeder without swapping the breaker frame. The ETU850 gives you curve shaping (LI, LSI, LSIG via optional modules), so selectivity with downstream breakers is programmable, not guesswork.
Breaking capacity — what the voltage tiers tell you
The interrupting rating changes sharply with system voltage. At 240 V it clears 330 kA symmetrical — enough for a high-capacity transformer secondary. At 415 V and 440 V it holds 242 kA. At 500 V the rating drops to 187 kA, and at 690 V it falls to 7.5 kA. The 690 V figure is the constraint: if your panel feeds a 690 V drive bus, this breaker's SCCR is only 7.5 kA, so upstream coordination or a current-limiting fuse may be required. The 330 kA at 240 V is the headline number for low-voltage distribution.
Thermal derating — the real-world current limit
The breaker is rated 400 A continuously at 40 °C through 50 °C. Above 50 °C the current must be derated: 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 60 °C, the usable setting is 350 A, not 640 A. The operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C.
Auxiliary and alarm switch complement
This variant ships with 2 auxiliary switches plus 1 trip alarm switch plus 1 electrical alarm switch (HQ designation). That gives you two NO/NC pairs for status feedback to a PLC or SCADA, a dedicated contact that changes state only on a trip event, and a separate electrical alarm output. No undervoltage release is fitted; no ground-fault monitoring module is included. The front face carries an IP40 protection rating — suitable for a clean indoor panel, not for washdown environments.
Lifecycle and sourcing posture
The 3VA2340-7KP32-0AL0 is listed as current-production (active lifecycle). It is part of the Siemens SENTRON 3VA series, which is the current generation replacing the earlier 3VL series. No successor has been announced. The part is sourced to order through independent distribution; availability and current pricing are confirmed at quote time against an RFQ.
Physical fit — dimensions and panel integration
Dimensions are 248 mm height, 138 mm width, 110 mm depth. The 138 mm width is a standard 3-pole MCCB footprint for the 3VA frame size. It mounts via four screws to a mounting plate or rear panel — no DIN rail. The 110 mm depth includes the rear terminals; allow additional clearance for cable bending radius below the breaker.