MCCB for Line Protection with Undervoltage Release
The Siemens SENTRON 3VA1220-5EF42-0DF0 is a 4-pole molded case circuit breaker (MCCB) designed for line protection, carrying a continuous current of 200 A at 40 °C ambient. Its interrupting ratings step down from 187 kA at 240 VAC to 17 kA at 690 VAC, which means it can handle high-fault scenarios at common distribution voltages without cascading upstream — a key selectivity consideration for panel builders coordinating a main breaker with downstream feeders. The breaker includes an undervoltage release (UVR) and a 1 auxiliary + 1 trip alarm switch (HQ), so it integrates directly into safety circuits that need to drop the load on loss of control voltage.
Thermal Derating and Power Loss
The 200 A rating holds flat from 40 °C to 50 °C, then derates to 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. Maximum power loss is 44.5 W. In a sealed, uncooled enclosure, that loss figure drives the internal temperature rise — factor it into your thermal budget early.
Physical Fit and Mounting
The breaker measures 70 mm deep, 140 mm wide, and 158 mm high. The 4-pole body occupies a standard MCCB footprint in the SENTRON 3VA family — check your panel's gland-plate clearance and DIN-rail or screw-mount provisions. The basic switch assembly is order code 3VA12205EF420AA0, which is the internal mechanism; the unit ships as a complete breaker.