The Siemens SENTRON 3VA1120-3EF36-0DC0 is a 3-pole molded case circuit breaker (MCCB) rated 20 A at 40 °C, with a breaking capacity of 75.6 kA at 240 V AC. It carries an undervoltage release and two factory-fitted HQ auxiliary switches, designed for line protection in distribution panels.
Breaking capacity and selectivity
With 75.6 kA at 240 V and 52.5 kA at 415 V, this MCCB handles high fault currents typical of main feeders. The interrupting rating drops to 32 kA at 440 V and 11.9 kA at 500 V or 690 V, so verify the available fault current at your system voltage before specifying. Rated insulation voltage is 800 V.
Current derating across temperature
The breaker holds 20 A continuously from 40 °C through 55 °C, then derates to 19 A at 60 °C through 70 °C. In a warm enclosure or near other heat sources, the 19 A ceiling at elevated temperatures matters for branch circuit sizing. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C.
Auxiliary and undervoltage release
Two HQ auxiliary switches are built in, plus an undervoltage release (UVR). The UVR trips the breaker if control voltage drops below a threshold, common for emergency-stop or undervoltage protection schemes. No ground-fault monitoring or communication module on this variant.
Dimensions and panel fit
Width 76.2 mm (3 in), depth 70 mm (2.76 in), height 130 mm (5.12 in). The 3-pole footprint matches the SENTRON 3VA family, so a panel cutout for a 3VA1110 or 3VA1020 will accept this unit without rewiring the bus bars.