Siemens SENTRON 3VA1112-4FE46-0AA0 — 125 A 4-Pole MCCB with TM220 Release
The Siemens SENTRON 3VA1112-4FE46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 125 A and a TM220 thermal-magnetic release. The interrupting capacity reaches 121 kA at 240 V AC and 75.6 kA at 415 V AC — figures that govern its use in high-fault-current distribution panels where selectivity with downstream breakers is required. The 125 A rating holds flat up to 50 °C ambient; above that it derates to 114 A at 70 °C, so a panel running hot needs a bump in frame size or forced ventilation. The TM220 release provides adjustable thermal (overload) and fixed magnetic (short-circuit) trip characteristics. The adjustable li response value maxes at 1250 A, giving some flexibility to coordinate with downstream motor starters or feeder breakers. Insulation voltage is rated at 800 V, and the unit accepts DC operation up to 600 V — relevant for battery-bank or UPS output protection.
Physical Fit and Panel Integration
The breaker measures 70 mm deep, 101.6 mm wide, and 130 mm high. The 101.6 mm width (4 inches) is the standard 4-pole MCCB footprint for the SENTRON 3VA platform — it occupies four 25.4 mm pole positions on a DIN rail or mounting plate. The IP40 rating on the front means it is protected against tools and wires larger than 1 mm, but not against water ingress; install inside a panel with a sealed door for washdown areas. The N-conductor protection is set at 50% of the phase rating, a common configuration for 4-pole breakers in TN or TT systems where the neutral is not fully rated. The maximum power loss is 28.1 W — relevant for thermal budgeting inside a sealed enclosure with multiple breakers ganged together.
Operating Range and Environment
The breaker operates from -25 °C to 70 °C ambient, with storage from -40 °C to 80 °C. The 70 °C operating ceiling matches the derating curve endpoint — at that temperature the continuous current drops to 114 A, so a 125 A load at 70 °C would nuisance-trip. The 800 V insulation voltage allows use in 690 V systems with adequate clearance, and the 600 V DC rating covers most industrial DC bus voltages up to 500 V nominal.