What this breaker delivers
The Siemens SENTRON 3VA1225-4GF42-0AH0 is a 4-pole molded case circuit breaker on a 250 A frame, fitted with a TM240 thermal-magnetic overcurrent release and configured for line protection. Interrupting capacity runs 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V — the 240 V figure covers most North American panelboard fault-current scenarios, while the 415 V rating suits European 400 V distribution. Thermal derating is published per degree from 45 °C (250 A) through 70 °C (223 A); at 55 °C the continuous rating drops to 243.3 A, and at 60 °C to 236.5 A. Plan your load margin against the actual enclosure ambient, not the 40 °C reference. Rated insulation voltage Ui is 800 V; max DC operational voltage is 600 V. The N-conductor protection is rated at 100 %.
Panel fit and auxiliaries
Dimensions are 158 mm high × 140 mm wide × 70 mm deep — the 140 mm width is the 4-pole footprint; a panel cut out for a 3-pole 3VA frame leaves roughly 35 mm short per pole. Verify the gland-plate knockout pattern before drilling. Auxiliary contact version ships as 2 auxiliary switches plus 1 trip alarm switch (HQ configuration). The front-face trip indicator is present, so fault isolation doesn't require pulling the cover. Front IP40 protection keeps dust out of the enclosure face; no undervoltage release, no voltage trigger, no phase-failure detection, no ground-fault monitoring, and no communication function are built in on this variant.
Lifecycle and sourcing
The supplied basic switch order code is 3VA12254GF420AA0; the reference code per IEC 81346-2 is Q. Operating temperature range is -25 °C to +70 °C; storage range is -40 °C to +80 °C.