The Siemens 3VA1120-4EE42-0AA0-ZD00 is a 4-pole IEC frame 160 circuit breaker from the 3VA1 series, rated In=20A with a TM220 thermal-magnetic trip unit. Its breaking capacity class S delivers Icu=36kA at 415 VAC, which means it can safely interrupt fault currents up to that level without upstream damage — critical for panel selectivity in a 415 V distribution board.
The overload protection Ir is adjustable from 14 A to 20 A, and the short-circuit protection Ii is fixed at 16 x In (320 A). The N conductor is unprotected — the neutral pole does not have an overload element, which is typical for 4-pole breakers used in TN or IT systems where the neutral is not expected to carry unbalanced load continuously. The nut keeper kit is included for DC Power OEM applications, so the breaker ships ready for panel-mounting with captive hardware.
This variant is designated for DC Power OEM in China, meaning the packaging and any accompanying documentation are tailored for that market. The breaker itself is a standard 3VA1 IEC device, so its electrical ratings and footprint are identical to the global version.