SENTRON 3VA1112-4EE42-0AA0 — 125 A MCCB, TM220 Release
The Siemens SENTRON 3VA1112-4EE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated at 125 A continuous current with a TM220 thermal-magnetic overcurrent release. It's designed for line protection in distribution panels and industrial switchgear, carrying an 800 V rated insulation voltage (Ui). Breaking capacity is the headline here: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That means this breaker can safely interrupt very high fault currents at lower voltages — critical for industrial feeders close to the transformer secondary where available fault current is highest.
Thermal Derating and Ambient Conditions
The 125 A rating holds up to 50 °C ambient. Above that, derating is gradual: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. If this MCCB sits near hot equipment — like a drive cabinet or near a furnace zone — you need to factor that curve rather than relying on the 125 A nameplate. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The IP40 protection on the front means it's fine inside a clean panel but not for washdown or outdoor exposure without an enclosure. Maximum power loss is 28.1 W — that's the heat it dumps into the enclosure. In a densely packed panel, that adds up; ensure adequate ventilation or forced cooling if multiple breakers are ganged.
Lifecycle and Sourcing
Dimensions are 70 mm depth, 101.6 mm width, 130 mm height — standard 4-pole MCCB footprint for DIN-rail or panel-mount integration. The 70 mm depth is the projection from the mounting surface, so verify clearance against enclosure door depth and busbar runs.