What this MCCB is and what it does
The Siemens SENTRON 3VA2125-5KQ36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current on a 300 A frame, designed for line protection in distribution panels. Its interrupting capacity reaches 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 — so it handles high-fault-current scenarios common in industrial switchboards without cascading upstream. The 86 mm depth and 105 mm width fit standard MCCB panel footprints, and the unit includes communication capability and ground-fault monitoring via summation current formation on the L-conductor.
Environmental and compliance range
Operating temperature spans -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 0.6 W. The insulation voltage is rated 800 V. These figures define the breaker's thermal limits in enclosed panels — a 70 °C ambient ceiling means it can sit in a non-ventilated cabinet near other heat sources without derating below its 25 A continuous rating.