The Siemens SENTRON 3VA1112-5MH32-0CA0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, designed for starter protection. It carries a TM120M thermal-magnetic overcurrent release and an integrated undervoltage release (UVR). Breaking capacity hits 187 kA at 240 V and 121 kA at 415 V, so it handles high-fault utility feeds without cascading upstream.
Current derating and thermal limits
Full 125 A rating holds through 50 °C ambient. Above that it derates linearly: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, 114 A at 70 °C. If your panel interior runs hot — say, a packed enclosure near a motor drive — check the 70 °C figure (114 A) against your continuous load. Maximum power loss is 30.6 W, which matters for enclosure heat calculations.
Breaking capacity by voltage
Rated short-circuit breaking capacity (Icu) varies with system voltage: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. At 690 V the 7.5 kA figure is the limiting case — verify your available fault current if the MCCB feeds a 690 V drive input.
Undervoltage release and dimensions
The built-in undervoltage release (UVR) trips the breaker when line voltage drops below a set threshold — standard on this variant for applications where under-voltage protection is mandatory (e.g., motor starters that must not auto-reclose). Physical footprint: 130 mm high, 76.2 mm wide, 70 mm deep. That 70 mm depth is the dimension to check against your enclosure back-panel clearance and any busbar stack-up behind the breaker.