What this breaker is and what it carries
The Siemens SENTRON 3VA1125-3EF32-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated 25 A at 40 °C, designed for line protection in distribution panels and industrial feeder circuits. It ships with an integrated undervoltage release (UVR) as the auxiliary release — specified as undervoltage release (UVR) type — and uses a TM240 thermal-magnetic overcurrent release. No communication function, no trip indicator, no ground-fault monitoring on this variant.
Interrupting capacity — what the voltages tell you
This MCCB's interrupting capacity varies sharply with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. For a 480 V panel feed, the 32 kA at 440 V figure is the closest published rating — expect the actual SCCR at 480 V to fall between the 440 V and 500 V curves. On a 400 V distribution board, the 52.5 kA at 415 V gives you selectivity headroom for most downstream branch breakers.
Thermal derating and power loss
The breaker carries a full 25 A from 40 °C through 50 °C without derating. At 55 °C it drops to 24 A, at 65 °C to 23 A, and holds 23 A through 70 °C. Maximum power loss is 11 W at rated load. Rated insulation voltage is 800 V. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions: 70 mm depth, 76.2 mm width, 130 mm height. Standard 3-pole MCCB footprint — mounts in the usual panel cutout or on a mounting plate. No DIN-rail clip on this frame; expect bolted bus connections. The undervoltage release wiring needs a separate control voltage; verify polarity and coil rating against your 24 VDC or 110 VAC control supply before commissioning.