What this MCCB carries and where it fits
The Siemens 3VA1112-4EF36-0DA0 is a 3-pole SENTRON molded case circuit breaker rated for 125 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity hits 121 kA at 240 V and still holds 75.6 kA at 415 V — enough for high-fault panelboards and main feeder duty where selectivity with downstream breakers matters. The unit ships with an undervoltage release (UVR) fitted, so it can be wired into a safety circuit that drops the main breaker on loss of control voltage. Rated insulation voltage is 800 V, and the front face carries IP40 protection — fine for a clean indoor panel, but not washdown. The breaker is 76.2 mm wide, 130 mm tall, and 70 mm deep, which is the standard 3VA1112 frame footprint; it bolts into the same mounting pattern as other breakers in this series.
Thermal derating and operating range
The 125 A rating holds flat from 40 °C through 50 °C, then steps down: 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. If the panel ambient runs above 50 °C, size the breaker for the derated figure — the TM240 release won't trip early, but the continuous current limit drops. Operating ambient spans -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel fit and integration notes
The 76.2 mm width and 70 mm depth match the standard 3VA1112 frame — it drops into the same mounting holes and bus-bar connections as the 3VA1112-5EF32-0CA0 without rewiring. The UVR coil (order code 3VA9608-0BB25) is already installed; verify the control voltage matches your safety circuit before energizing. No auxiliary contacts are fitted on this variant, so add a separate auxiliary block if you need status feedback to a PLC.