What this MCCB does — and what the ratings actually mean
The Siemens SENTRON 3VA1132-4EF32-0KH0 is a 3-pole molded case circuit breaker rated for 32 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. That TM240 designation means the thermal trip element is fixed at 32 A — no field-adjustable thermal dial — and the magnetic instantaneous pickup is set at 240 A (7.5x In). For a panel-builder or MRO planner, this is a line-protection breaker, not a motor-protection device; it's sized for cable and busbar protection in distribution panels where you want a fixed thermal curve and no nuisance tripping from inrush. The breaking capacity figures tell the real story for selectivity coordination. At 240 V it interrupts 121 kA — that's a massive fault-current rating for a 32 A frame, meaning it can sit downstream of a transformer or a high-capacity bus without worrying about cascading failure. At 415 V it's still 75.6 kA, and at 690 V it drops to 11.9 kA. If your panel's available fault current at the breaker terminals is, say, 65 kA at 415 V, this unit clears it with headroom. The 800 V rated insulation voltage (Ui) confirms it's built for 690 V line-to-line systems. Thermal derating is published across the operating range: it holds full 32 A from 40 °C through 50 °C, then steps down to 30.72 A at 55 °C, 30.08 A at 60 °C, 29.44 A at 65 °C, and 28.8 A at 70 °C. If the breaker lives in a non-ventilated enclosure next to other heat sources, use the 55 °C or 60 °C column for your continuous load calculation.
Built-in auxiliaries and release options
This version ships with a factory-installed shunt trip (STL) release — order code 3VA9688-0BL33 for the integrated auxiliary trip module — plus 2 auxiliary switches and 1 trip alarm switch (HQ configuration). The shunt trip lets you remotely trip the breaker via a control voltage, which is standard for emergency-stop circuits or remote shutdown in automated lines. The trip indicator (mechanical flag) and voltage trigger are both present, so you get local visual confirmation of a trip event without needing to read the aux contacts. There is no undervoltage release, no communication module, no phase-failure detection, and no ground-fault monitoring on this variant. If your spec calls for any of those, you need a different 3VA suffix — this one is a straightforward line-protection breaker with remote trip capability only.
Physical fit and panel integration
Dimensions: 130 mm height, 76.2 mm width (3-pole frame), 70 mm depth. The width matches the standard 3-pole MCCB footprint for DIN-rail or screw-mount panel installation. IP40 on the front face — suitable for enclosed distribution boards; not rated for washdown or outdoor exposure without an additional enclosure. Storage temperature range is -40 °C to 80 °C; operating ambient is -25 °C to 70 °C. The 15 000 latching endurance cycles (mechanical) is typical for a distribution MCCB — not a switching-duty contactor, but fine for the occasional manual disconnect or test operation.