What this breaker brings to the panel
The Siemens 3VA1120-6GF42-0AA0-ZD00 is a 4-pole IEC frame 160 molded-case circuit breaker with a 70 kA interrupting capacity at 415 V (breaking capacity class H). The TM240 thermal-magnetic trip unit is set for a 20 A nominal rating (In), with adjustable overload protection (Ir) from 14 A to 20 A and short-circuit pickup (Ii) from 8 to 16 times In. The N conductor is protected at 100%, so it tracks the phase protection — no derating on the neutral path.
The nut keeper kit (included per the -ZD00 suffix) is specified for DC Power OEM installations in China, so the breaker ships with hardware that keeps fasteners captive during high-vibration environments like inverter cabinets or battery-bank distribution. The 4-pole configuration suits three-phase plus neutral applications where the neutral is switched and protected — common in IT or TN-S systems where you want a single breaker to disconnect all poles.