What this 3VA1 breaker carries
The Siemens 3VA1120-3GF42-0AA0-ZD00 is a 4-pole IEC frame 160 circuit breaker with breaking capacity class N — rated Icu=25kA at 415 V. That 25 kA interrupting rating at 415 V means it can safely clear a fault up to that level on a 400 V three-phase distribution board without the arc flashing over or the breaker rupturing. It's a line-protection device with a TM240 thermal-magnetic trip unit, set for an In=20 A nominal current. The overload protection band runs Ir=14 A to 20 A, and the short-circuit magnetic pickup is adjustable Ii=8 to 16 times In. The N-conductor protection is 100% rated, and it ships with a nut keeper kit. This variant is configured for a DC Power OEM based in China.
Where it fits in the panel
The 3VA1 frame 160 mounts on a DIN rail or can be screw-fixed to a backplate in a standard distribution board. The 4-pole form factor handles three-phase plus neutral, common in IEC panel builds for industrial or commercial sub-distribution. The nut keeper kit simplifies torque-down on the line and load terminals — a small detail that saves time during panel wiring.