What this MCCB delivers
The Siemens SENTRON 3VA2140-5MN32-0CC0 is a 3-pole molded case circuit breaker rated at 40 A continuous current (at 40 °C ambient) with a breaking capacity of 187 kA at 240 V AC. That 187 kA figure means it can safely interrupt a fault current up to that level without upstream cascading — critical for high-fault installations like transformer secondaries or large motor control centers. The ETU350M electronic trip unit provides adjustable overload and short-circuit protection, plus phase failure detection, so it catches a lost phase before the motor burns out. This is a motor-protection version with an integrated undervoltage release and two HQ auxiliary switches. The undervoltage release drops the breaker if control power falls below a threshold — useful for coordinated shutdown sequences on a line. The auxiliary switches signal status back to a PLC or annunciator panel.
Panel fit and derating
Dimensions: 86 mm deep, 105 mm wide, 181 mm tall. Rated current holds at 40 A from 40 °C up to 50 °C. At 55 °C it derates to 38.4 A, and at 70 °C to 36 A. If your panel ambient runs above 50 °C, factor that derating into the load schedule. Maximum power loss is 75 W — that's the heat the breaker dissipates at full load; account for it in enclosure thermal calculations.
Breaking capacity across voltages
Breaking capacity varies with system voltage: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. The 17 kA at 690 V is still adequate for most 690 V industrial grids — typical fault levels there are under 10 kA. The 187 kA at 240 V is exceptionally high, making this breaker a good choice for 240 V distribution where fault currents can be severe.