What this 3VA1 breaker carries
The Siemens 3VA1120-4EF36-0BA0 is a 3-pole IEC frame 160 circuit breaker in the 3VA1 series, rated for 20 A with a TM240 thermal-magnetic trip unit. Overload protection is adjustable from 14 A to 20 A; short-circuit pickup is set at 8 to 16 times In. Breaking capacity lands at 36 kA at 415 V — class S on the 3VA1 scale, sized for distribution panels where fault current runs high but the main bus stays below 160 A frame.
Undervoltage release and wiring
This unit includes a factory-fitted undervoltage release (UVR) that trips the breaker when control voltage drops below 24 V DC. The UVR coil holds at nominal 24 V DC; below roughly 18 V the breaker opens, which is the intended behavior for emergency-stop or power-loss sequences that need a positive open on control-power failure. Terminals are clamp-type — strip length around 8 mm, accepts 0.2–2.5 mm² solid or ferruled stranded. Mounts on standard DIN rail; the 3VA1 frame is the same footprint as the 3VA2 family, so panel cut-outs and busbar positions carry across.