What this MCCB delivers on the line
The Siemens 3VA1220-5MH32-0AB0 is a SENTRON molded case circuit breaker rated for 200 A continuous at 40 °C, with a TM120M thermal-magnetic overcurrent release. The 121 kA breaking capacity at 415 V means it can interrupt high fault currents typical in industrial distribution without upstream coordination headaches — a solid spec for plant main feeders or large motor branch circuits. The 3-pole design with 2 auxiliary switches HP gives you remote status feedback without adding a separate contactor block. Rated insulation voltage is 800 V, so it handles 480 V and 600 V class systems with margin. Max power loss 42 W — keep that in mind for enclosure thermal calculations if you're packing several breakers in a small panel.
Thermal derating and real-world current
At 40 °C this breaker carries a full 200 A. Derate linearly above that: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, 176 A at 70 °C. If your panel ambient runs warm — say near a drive cabinet or in a non-conditioned enclosure — use the 55 °C or 60 °C column for sizing. The TM120M release is factory-set for motor or mixed loads; no voltage-trip or ground-fault module fitted as standard.
Breaking capacity across voltage levels
The interrupting ratings tell you where this breaker fits in the fault-current hierarchy: 187 kA at 240 V (low-voltage distribution), 121 kA at 415 V (common industrial), 75.6 kA at 440 V, 30 kA at 500 V, and 4.5 kA at 690 V. For a 480 V system you interpolate between the 440 V and 500 V numbers — still well above typical available fault current in most plants. The 690 V rating is low, so verify if your system runs at that voltage.