Siemens 3VA1220-4GF42-0HH0 — 200 A MCCB with TM240 Release
The Siemens 3VA1220-4GF42-0HH0 is a SENTRON molded case circuit breaker (MCCB) rated for 200 A continuous current at 40 °C, with a 4-pole configuration and a TM240 thermal-magnetic overcurrent release. It carries a 121 kA interrupting rating at 240 V and 75.6 kA at 415 V, making it suitable for high-fault-current industrial distribution panels where selectivity and short-circuit coordination are critical.
Interrupting Capacity and Derating Profile
Interrupting capacity drops from 121 kA at 240 V to 75.6 kA at 415 V, then to 25 kA at 440 V, and further to 11.9 kA at 690 V. This steep derating with voltage means the breaker's SCCR must be verified against the actual line-to-line voltage at the point of installation — at 480 V systems the available fault current should be checked against the 440 V rating as a conservative bound. Continuous current holds at 200 A from 40 °C through 50 °C ambient, then derates to 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. In a sealed, uncooled enclosure the effective ampacity may be lower than the nameplate 200 A — plan for the actual ambient inside the panel.
The breaker measures 70 mm deep by 140 mm wide by 158 mm high, fitting standard SENTRON 3VA panel cutouts. The 100% N-conductor protection design means the neutral pole is fully rated and trips with the phase poles — no derating needed for 4-wire systems with balanced or unbalanced loads.