What this MCCB carries — and what it means for your panel
The Siemens SENTRON 3VA2040-6KQ46-0AA0 is a 4-pole molded case circuit breaker rated for 40 A continuous current, designed for line protection in distribution panels. The 242 kA breaking capacity at 240 V means it can interrupt a fault current of that magnitude without upstream damage — critical for high-fault installations like transformer secondaries or large motor control centers. At 415 V and 440 V it still holds 187 kA, dropping to 121 kA at 500 V and 3 kA at 690 V, so the voltage class of your supply determines the fault-clearing headroom you actually get. Rated insulation voltage is 800 V, which covers 480 V and 600 V class systems with margin. The 2.2 W maximum power loss is low enough that ventilation spacing in a standard enclosure is adequate — no forced cooling required for this breaker alone. A communication function is built in, so this unit can report status or trip events over a bus without an add-on module — useful for a maintenance team that wants to know which breaker opened before walking the panel.
Mounting and integration notes
Dimensions are 181 mm height, 140 mm width, 86 mm depth — a standard 4-pole MCCB footprint that fits Siemens SENTRON mounting plates and most DIN-rail adapter kits. The 86 mm depth is shallow enough for 200 mm deep enclosures with clearance for outgoing cables. The breaker accepts a continuous current range from 60 A minimum to 480 A maximum via interchangeable trip units, but this specific variant is factory-set at 40 A. If your load draw is higher, you would select a different 3VA2 order code with the appropriate rating plug.
Environmental and compliance
Operating temperature spans -25 °C to 70 °C, with storage from -40 °C to 80 °C. The 40 A rating is maintained across the full operating range — no derating needed up to 70 °C ambient, which is unusual for an MCCB and simplifies panel sizing in hot environments like pump houses or steel mills. Ground-fault monitoring uses summation current formation on L+N conductors, meaning it detects imbalance between phase and neutral — standard for solidly-grounded systems. No undervoltage release or voltage trip is fitted on this variant.