Siemens SENTRON 3VA1220-4EF32-0CD0 — 200 A MCCB with TM240 Release
The Siemens SENTRON 3VA1220-4EF32-0CD0 is a 3-pole molded case circuit breaker rated for 200 A at 40 °C, fitted with a TM240 thermal-magnetic overcurrent release. The interrupting ratings span 121 kA at 240 V down to 11.9 kA at 690 V, giving selectivity headroom for most industrial distribution panels.
Above 55 °C the rating derates linearly to 176 A at 70 °C — a critical factor for sealed or high-ambient enclosures. The TM240 release combines a thermal element for overload protection and a magnetic element for short-circuit response; the 240 in the designation indicates the magnetic trip threshold is 240 A (120% of the 200 A frame). Interrupting capacity at 240 V is 121 kA, at 415 V it is 75.6 kA, and at 690 V it drops to 11.9 kA. For a 480 V panel (common in North America) the relevant value is the 415 V figure — 75.6 kA — which covers most transformer-fed services. Power loss is 42 W maximum at rated current — useful for thermal calculations inside a crowded enclosure. The breaker includes three auxiliary switches (HQ design) for remote status indication, and the undervoltage release is factory-fitted, not a field-add-on.