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. Rated insulation voltage is 800 V, and the front face carries IP40 protection — suitable for enclosed panel mounting where the front is accessible but not exposed to washdown.
Thermal derating and power loss
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.
Dimensions and panel fit
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.