What this MCCB delivers
The Siemens 3VA1120-4EF36-0BC0 is a 3-pole SENTRON molded case circuit breaker rated for line protection, carrying a continuous current of 20 A across the 40 °C to 55 °C ambient range, derating to 19 A at 60 °C through 70 °C. Its interrupting capacity reaches 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 — figures that define the available fault current the breaker can safely clear at each voltage level, critical for SCCR compliance in the panel. The unit includes a factory-fitted undervoltage release (UVR) and two auxiliary switches (HQ design), so it drops the load on loss of control voltage and reports breaker status back to the PLC or annunciator without adding external relays.
Panel fit and mounting
At 76.2 mm wide, 130 mm tall, and 70 mm deep, this MCCB occupies three standard 25 mm DIN-rail modules — verify the gland plate and adjacent device spacing before committing the backpanel layout. Rated insulation voltage is 800 V, so it suits 480 V and 600 V class panels with headroom to the bus.