Part identity and key ratings
The Siemens 3VA1140-3EF32-0AC0 is a SENTRON molded case circuit breaker (MCCB) configured for line protection in a 3-pole, 40 A frame. It carries a TM240 thermal-magnetic overcurrent release — fixed thermal and magnetic trip settings, no electronic adjustment — so the trip curve is determined at the factory and not field-configurable. Rated continuous current Iu is 40 A, and the insulation voltage Ui is 800 V. Breaking capacity is specified across four voltage levels: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. For a 40 A frame these are high-interrupting ratings — the 415 V figure in particular gives headroom for most industrial distribution panels without needing a current-limiting upstream device. Thermal derating is minimal up to 50 °C — the breaker holds its full 40 A rating. Above that it steps down: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. If the panel ambient runs hot, the 40 A frame still delivers usable capacity without a frame-size jump.
Auxiliary contacts and panel integration
This variant ships with two auxiliary switches (HQ type) built in — no separate add-on module needed for status feedback to a PLC or indication lamp. The auxiliary contacts share the same housing, saving a DIN-rail slot. No undervoltage release, no shunt trip, no ground-fault module on this configuration; if those are required for the application, this is not the right order-code variant. Dimensions are 130 mm height, 76.2 mm width (3-pole), and 70 mm depth. The width matches the standard 3-pole MCCB footprint for panel cutouts or DIN-rail mounting. Front protection is IP40 — suitable for enclosed panel use, not for washdown or outdoor exposure without a secondary enclosure. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage limit is the handling and logistics boundary — the breaker can sit in a cold warehouse or hot container without damage, but the operating range governs in-service panel conditions.