What this 200 A MCCB delivers
The Siemens SENTRON 3VA1220-4GF42-0AG0 is a 4-pole molded case circuit breaker rated for 200 A continuous at 40 °C, with a TM240 thermal-magnetic overcurrent release. It's designed for line protection — meaning it sits at the feeder or main breaker position in a distribution panel, protecting downstream cables and buswork against overloads and short circuits. The interrupting ratings climb to 121 kA at 240 V and 75.6 kA at 415 V, which gives selectivity headroom for high-fault installations like industrial substations or large motor control centers. Rated insulation voltage is 800 V, so the breaker can be applied on 480 V and 600 V class systems with margin. The TM240 release is a fixed thermal-magnetic unit — no interchangeable trip units, which simplifies spares stocking but means the breaker is dedicated to the 200 A frame. If the load grows beyond that, you swap the whole breaker, not just the trip.
Interrupting capacity across voltage levels
This MCCB delivers 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. That's a steep derate curve above 440 V, which is typical for a compact MCCB frame. On a 480 V system the 52.5 kA rating still covers most utility transformer sizes; on a 690 V wind or marine circuit the 11.9 kA limit means you need to verify the available fault current at the panel.
Thermal derating and ambient temperature
The breaker holds 200 A continuously from 40 °C up to 50 °C. Above that it 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 ambient runs hot — say near a furnace line or in a non-conditioned enclosure — the 70 °C figure (176 A) is the one to size against. Operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Built-in auxiliary and alarm switching
Factory-fitted with one auxiliary switch and one trip alarm switch (HP type). The auxiliary tracks the breaker's open/closed position for status feedback to a PLC or indicator light. The trip alarm signals only on a fault trip — not on manual switching — so it can trigger an alarm annunciator or a shunt-trip lockout circuit. No undervoltage release or communication module is included; those would need to be added externally if required.