SENTRON 3VA1112-6FF46-0AA0 — 125 A MCCB with TM240 Release
The Siemens SENTRON 3VA1112-6FF46-0AA0 is a 4-pole molded case circuit breaker rated for 125 A continuous current, fitted with a TM240 thermal-magnetic overcurrent release. It is a line-protection device, not a motor-protection or ground-fault variant — the TM240 release is sized for feeder and distribution duty where the full-load current is close to the frame rating. Interrupting capacity varies sharply with system voltage: 220 kA at 240 V, 154 kA at 415 V, 76 kA at 440 V, and 17 kA at 500 V and 690 V. At 415 V — a common industrial distribution level — the 154 kA rating covers most utility-transformer-fed fault currents without requiring current-limiting fuses upstream. Thermal derating is mild up to 50 °C (full 125 A), then drops to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. For a panel with ambient near 60 °C, the effective continuous current is 120 A — a 4% reduction that rarely forces a frame upsizing, but worth confirming if the load is already at 125 A.
Dimensions and Panel Fit
Footprint is 101.6 mm wide by 130 mm tall by 70 mm deep. IP40 front protection. The N-conductor protection is set at 50% of the phase rating, a standard configuration for 4-pole breakers in TN or TT systems where the neutral is not expected to carry full phase current.
Key Ratings and Release Design
Rated insulation voltage is 800 V, and maximum DC operational voltage is 600 V — the breaker can be used in DC circuits up to that level, though the interrupting capacity on DC must be verified against the manufacturer's DC derating curves. Power loss at rated current is 28.1 W, a figure to include in thermal calculations for a multi-breaker panel. Endurance is rated at 20,000 mechanical operations.