What this MCCB delivers
The Siemens SENTRON 3VA1112-5EF36-0AB0 is a 3-pole molded case circuit breaker (MCCB) rated for 125 A continuous current at 40 °C, with a TM240 thermal-magnetic trip unit. It delivers a 187 kA interrupting capacity at 240 V AC, dropping to 121 kA at 415 V and 75.6 kA at 440 V — numbers that matter when coordinating with upstream gear in a high-fault panel. The 125 A frame stays flat across the 40–50 °C band (125 A at 50 °C), then derates to 114 A at 70 °C, so it handles warm enclosure environments without oversizing.
Line protection design
This MCCB is designed for line protection (feeder or main breaker duty), not motor branch-circuit protection — no undervoltage release, no ground-fault monitoring, no communication module built in. The TM240 thermal-magnetic release handles overload and short-circuit. Rated insulation voltage is 800 V, giving headroom for 690 V systems. Power loss is 28.1 W maximum at rated current.
Installation and compliance
Mounts on a DIN rail or panel-mount baseplate with 76.2 mm width (3 in) and 130 mm height (5.12 in). Depth is 70 mm (2.76 in), which matters when the enclosure door clearance is tight. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. The auxiliary switch block carries 2 HP-rated switches for remote status indication — no trip indicator on the front face, so plan on a panel lamp or PLC input if you need visual fault feedback.