Siemens SENTRON 3VA1225-6GF42-0CH0 — 250 A 4-Pole MCCB for Line Protection
The Siemens 3VA1225-6GF42-0CH0 is a SENTRON molded case circuit breaker rated for 250 A continuous current with a 4-pole configuration, designed specifically for line protection in distribution panels. Its interrupting capacity is voltage-dependent: 220 kA at 240 VAC, 154 kA at 415 VAC, 75.6 kA at 440 VAC, 30 kA at 500 VAC, and 17 kA at 690 VAC — figures that govern the available fault current the breaker can safely clear at each system voltage. The breaker includes an undervoltage release (UVR) as the auxiliary release type, plus two auxiliary switches and one trip alarm switch (HQ configuration), providing status feedback for monitoring and control circuits.
Thermal Derating and Operating Range
The 250 A rating holds at ambient temperatures up to 50 °C. Above that, the continuous current must be derated: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss at rated current is 59.5 W.
Physical Fit and Panel Integration
Dimensions are 158 mm height, 140 mm width, and 70 mm depth — a 4-pole frame that mounts into standard distribution panelboards or switchgear cubicles. The depth of 70 mm (2.76 in) is the dimension to check for gland-plate clearance and enclosure depth. Rated insulation voltage is 800 V, confirming suitability for 690 VAC systems with margin.