What this MCCB delivers
The Siemens 3VA1120-5GE46-0AA0 is a 4-pole SENTRON molded case circuit breaker (MCCB) rated 20 A continuous, with a TM220 thermal-magnetic overcurrent release. The 187 kA breaking capacity at 240 V means it can interrupt very high fault currents without upstream fuses or a bigger breaker — that is the spec that decides whether this part clears a high-available-fault panelboard without cascading damage. Rated insulation voltage is 800 V, and the breaker carries a 12 W maximum power loss at full load — a number to check against enclosure thermal rise if you are packing several in a small panel.
Breaking capacity across voltages
The 3VA1120-5GE46-0AA0 delivers 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. That steep drop above 440 V is typical for an MCCB with a 20 A frame — the arc extinction energy scales with voltage, and the 17 kA at 690 V is the real limit for 690 V line-side faults. For a 480 V panel the 75.6 kA at 440 V is the closest published figure; coordination studies should interpolate conservatively.
Thermal derating and operating range
The breaker holds full 20 A rating from 40 °C through 55 °C ambient. At 60 °C it derates to 19 A, and holds that through 70 °C. No derating needed for most panel environments — only tight enclosures or adjacent heat sources push it past 55 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.