Rated current and thermal derating
The Siemens 3VA1220-5EF42-0AJ0 is a SENTRON molded case circuit breaker (MCCB) with a TM240 thermal-magnetic release, rated 200 A continuous at 40 °C. That 200 A holds flat through 50 °C, then derates linearly to 176 A at 70 °C — the maximum operating ambient. For a 200 A bus or feeder on a 4-pole line, this breaker carries full load without headroom loss up to 50 °C; above that, the derating curve governs the continuous current the breaker can pass without nuisance tripping.
Breaking capacity across voltage levels
Breaking capacity is voltage-dependent, as expected for an MCCB. At 240 V AC, the 3VA1220-5EF42-0AJ0 interrupts 187 kA; at 415 V, 121 kA; at 440 V, 75.6 kA; at 500 V, 30 kA; and at 690 V, 17 kA. For a 480 V panel (common in North American industrial distribution), the 30 kA at 500 V is the relevant number — enough for most service-entrance and feeder applications where the available fault current is under 30 kA. The 187 kA at 240 V covers high-fault locations like transformer secondaries.
Physical fit and panel integration
Dimensions: 70 mm deep, 140 mm wide, 158 mm tall. The 140 mm width is standard for a 4-pole SENTRON 3VA frame; it occupies four 35 mm DIN-rail modules. Panel cutout and mounting pattern match the 3VA platform — no adapter plate needed for a standard Siemens switchboard or distribution panel. The 42 W maximum power loss at full load should be factored into enclosure thermal calculations, particularly in sealed or low-ventilation cabinets.
Auxiliary switch complement
Factory-fitted with two auxiliary switches and one trip-alarm switch (HP type). This covers status feedback for the breaker's open/closed position and a separate signal for trip events — enough for a standard remote monitoring or interlocking scheme without an external accessory module.