The Siemens 3VA2125-5KQ42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection. It carries a 25 A continuous current at ambient temperatures from 40 °C all the way up to 70 °C — no derating needed in a hot control room or near a kiln. The 4-pole design with an ETU860 electronic trip unit gives you adjustable protection curves and onboard communication for integration into a plant-wide monitoring system.
Breaking capacity — what the numbers mean for your fault level
This breaker is rated to interrupt 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V. Those are the maximum fault currents it can safely clear at each voltage level. If your plant's available fault current at the panel is, say, 100 kA at 415 V, this breaker has headroom. At 690 V the 3.7 kA rating is lower — verify your system's prospective short-circuit current at that voltage before committing the BOM line.
Panel fit and environment
Dimensions are 181 mm high, 140 mm wide, 86 mm deep. The front face carries IP40 protection — sealed against tools and small solids, but not against dust ingress. In a cement plant or any dusty environment, plan for an enclosure that keeps airborne grit off the breaker face. The storage range spans -40 °C to 80 °C, so it handles site laydown before installation.