What the ratings mean for fit
The Siemens 3VA1220-4GF42-0BC0 is a 4-pole IEC frame 250 molded-case circuit breaker from the 3VA1 series, rated for line protection with a TM240 thermal-magnetic trip unit. The breaking capacity class S delivers Icu=36kA at 415 V AC — that is the maximum fault current it can safely interrupt without damage, sized for industrial distribution panels where the prospective short-circuit current at the bus is known to be under that level. The In=200 A continuous rating, with adjustable overload protection Ir=140 A…200 A and short-circuit pickup Ii=5…10 x In, lets the panel builder dial in the trip curve to match the downstream cable and load without swapping the breaker body. The built-in undervoltage release (UVR) operates on 24 V DC, so the breaker trips when control voltage drops — common in safety circuits or emergency-stop chains where loss of the holding coil must open the main contacts. The N-conductor protection is set at 100% of the phase rating, meaning the neutral pole is fully rated and protected, not just switched. A nut keeper kit is included for secure terminal fastening in high-vibration panels.
Panel integration notes
The 3VA1 frame mounts on a DIN rail or can be screw-fixed to a backplate in a standard industrial enclosure. The 4-pole footprint occupies four module widths; plan gland-plate space for the incoming cable lugs and the UVR wiring (24 V DC, polarity-sensitive). The TM240 thermal-magnetic unit is non-interchangeable in the field — the Ir and Ii adjustments are the only on-site tuning available.