What it is and what it does
The SENTRON 3VM1125-4ED22-0AA0 is a 2-pole molded case circuit breaker (MCCB) rated for line protection, carrying 25 A continuously at 40 °C and delivering a 121 kA interrupting capacity at 240 V AC — enough to handle high-fault utility feeds or large motor branch circuits without upstream fuses. The TM210 thermal-magnetic release handles overload and short-circuit protection in one package, with an adjustable li max of 320 A for short-circuit pickup. Rated insulation voltage is 500 V, and maximum operating voltage is 415 V AC or 250 V DC.
Thermal performance and real-world loading
The current rating holds flat at 25 A from 40 °C through 50 °C, then steps down to 24 A at 55–60 °C and 23 A at 65–70 °C — useful when the breaker sits inside a warm enclosure near drives or transformers. Maximum power loss is 6 W, so it won't cook adjacent components in a dense panel.
Physical fit and environment
At 70 mm deep, 50.8 mm wide, and 130 mm tall, this 2-pole MCCB fits standard distribution panelboards and motor control center buckets. IP40 on the front means it's protected against tools and small wires poking in, but it's not sealed against washdown — keep it inside a dry enclosure. Operating range spans -25 °C to 70 °C, with storage from -40 °C to 80 °C, so it handles unheated warehouses and outdoor cabinets in most climates.