The Siemens 3VA1220-4GF42-0AC0 is a SENTRON molded case circuit breaker (MCCB) rated for 200 A continuous, with a TM240 thermal-magnetic overcurrent release. It is a 4-pole unit designed for line protection, meaning it sits upstream of branch feeders and handles fault interruption before downstream devices see the full stress. Breaking capacity is the headline number here: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. Those figures tell you the maximum fault current this breaker can safely interrupt at each voltage level — critical for selectivity studies and SCCR compliance on the panel nameplate. Current rating holds at 200 A up to 50 °C ambient, then derates: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. If the panel runs hot, the actual load must stay under the derated curve — the 200 A label is only valid below 50 °C.
Sizing and integration
Footprint: 140 mm wide, 158 mm tall, 70 mm deep. That 70 mm depth means it fits standard 200 mm deep enclosures without crowding the gland plate. Four poles in a single block — no ganging required for three-phase-plus-neutral applications. Insulation voltage rated at 800 V, so it handles 690 V systems with margin. Power loss maxes at 42 W — factor that into enclosure thermal calculations if you're packing multiple breakers in a small cabinet.
Lifecycle and compliance
The breaker ships with two auxiliary switches (HQ design) as standard. No undervoltage release, no ground-fault monitoring, no communication function on this variant — it's a straight thermal-magnetic line-protection device. The supplied basic switch is order code 3VA12204GF420AA0.