SENTRON 3VA1125-5ED36-0AA0 — 25 A MCCB, 187 kA Breaking Capacity
The Siemens 3VA1125-5ED36-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated at 25 A continuous current at 40 °C, with a thermal-magnetic TM210 release. It carries a 3-pole configuration and delivers a massive 187 kA breaking capacity at 240 V AC — enough to ride through a fault on the secondary side of a large distribution transformer without cascading upstream. Breaking capacity drops with voltage: 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V or 690 V. At 40 °C ambient the breaker holds 25 A across all poles; derating starts at 55 °C (24 A) and reaches 23 A at 70 °C. The rated insulation voltage is 800 V, so it is comfortable in 480/277 V or 400/230 V panels with headroom for transient overvoltages.
Panel Fit and Integration
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits most 600 V panelboards and motor control center buckets. IP40 on the front means it is protected against tools and wires >1 mm, but not against moisture; install in a dry enclosure or add a cover. Maximum power loss is 8.5 W, so heat dissipation within a densely packed panel is manageable.