Key ratings and what they mean for fit
The 3VA1220-4EF32-0KC0 is a Siemens SENTRON molded case circuit breaker (MCCB) designed specifically for line protection — meaning it is sized to protect a feeder or main distribution bus, not a motor or transformer branch. Rated 200 A continuous at 40 °C through 50 °C, it derates to 176 A at 70 °C, so the ambient temperature of the enclosure directly governs the usable current — a panel hitting 55 °C drops the rating to 194 A. Breaking capacity is voltage-dependent: 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. The 3-pole frame handles three-phase systems up to a rated insulation voltage of 800 V.
Deployment context and auxiliary options
This MCCB ships with two auxiliary switches (HQ design) integrated and a shunt trip release (STL) — the shunt trip allows remote tripping via a control signal, which is useful for emergency-stop circuits or supervisory shutdown. No undervoltage release and no ground-fault monitoring are included, so if those functions are required they must be added externally or specified on a different variant. The breaker is designed for line protection only — not for motor or generator protection — and carries no communication function or trip indicator. Dimensions: 105 mm wide, 158 mm high, 70 mm deep — standard 3-pole MCCB footprint for panel mounting. Operating temperature range -25 °C to 70 °C; storage from -40 °C to 80 °C. Maximum power loss is 42 W — factor this into enclosure thermal calculations.