Siemens 3VA1040-3ED36-0BH0 — 40 A MCCB for Line Protection
The Siemens 3VA1040-3ED36-0BH0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A at 40 °C, with a 3-pole configuration designed for line protection. Its breaking capacity reaches 75.6 kA at 240 V AC, stepping down to 52.5 kA at 415 V and 32 kA at 440 V — figures that define the fault-current headroom available for panel coordination studies. The unit includes an undervoltage release (UVR) and comes fitted with two auxiliary switches plus one trip alarm switch (HQ).
Current Rating and Thermal Derating
The breaker holds its full 40 A rating from 40 °C through 50 °C. Above that, the datasheet shows a gradual derating: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. For a panel that runs warm — say, adjacent to drives or transformers — that 36 A floor at 70 °C is the figure to use for continuous load planning, not the 40 A nameplate.
Breaking Capacity Across Voltages
This MCCB delivers 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. The steep drop above 440 V means the available fault current at the panel's service voltage must be verified against the 7.5 kA limit at 690 V — a common oversight when the same breaker is specified across multiple voltage tiers.
Physical Fit and Panel Integration
Dimensions are 130 mm high, 76.2 mm wide, and 70 mm deep. The 3-pole width of 76.2 mm (3 inches) is standard for this class of MCCB; verify the DIN-rail or mounting-plate spacing against the existing panel layout. The unit accepts bolt-on or plug-in connections per the SENTRON 3VA system, and the 70 mm depth leaves clearance for rear-access wiring in a typical 200 mm deep enclosure.