Line protection MCCB with TM240 release
The Siemens SENTRON 3VA1125-4EF36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, with a TM240 thermal-magnetic overcurrent release and a continuous current of 25 A across the 40 °C to 50 °C ambient range. Breaking capacity reaches 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V — figures that govern selectivity coordination and SCCR headroom in the distribution board.
The 25 A rating holds up to 50 °C; above that it derates to 24 A at 55–60 °C and 23 A at 65–70 °C. Maximum power loss is 8.5 W, which factors into enclosure thermal calculations when grouping multiple breakers.
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — a 3-pole footprint that fits standard SENTRON 3VA mounting bases and busbar systems. Depth of 70 mm leaves clearance behind the gland plate for wiring and lug access.