The Siemens SENTRON 3VA1125-6EF32-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A at 40 °C, designed for line protection in distribution panels. It carries a 220 kA breaking capacity at 240 V — that's the fault it'll interrupt cleanly without welding its contacts or blowing apart, which matters when you're feeding a panel fed from a high-capacity transformer.
Ratings and what they mean on a real line
The 25 A rating holds flat from 40 °C up to 50 °C; it only starts to derate at 55 °C (24 A) and 65 °C (23 A). That means in a warm panel — say, one sitting next to a hot motor starter or a VFD — you still get full ampacity through most operating conditions. The 3-pole configuration covers three-phase loads, and the 800 V rated insulation voltage gives headroom for 480 V or 600 V systems. Breaking capacity drops as voltage climbs: 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. If your service entrance is 480 V, you're working with the 121 kA figure — still plenty for most industrial mains, but worth checking against your available fault current. This MCCB includes an undervoltage release (UVR) — the TM240 thermal-magnetic trip unit inside. That UVR means if your control voltage dips or drops, the breaker opens automatically. Handy for machinery where you want a guaranteed stop on power loss, but be aware it adds a coil draw (around 11 W max power loss) that stays energized during normal operation.
Panel fit — dimensions and mounting
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep. That's a standard 3-pole MCCB footprint — it'll mount on a DIN rail or bolt directly into a panel baseplate. The 70 mm depth means it clears most shallow enclosures, but check your gland plate clearance if the panel is tight.