Breaking capacity and trip curve
The 3VA1112-6GE42-0AA0-ZD00 is a 4-pole IEC frame 160 molded case circuit breaker rated 125 A continuous with a 70 kA interrupting capacity at 415 V (breaking capacity class H). The TM220 thermal-magnetic trip unit provides overload protection adjustable from 88 A to 125 A (Ir) and a fixed short-circuit pickup of 10 x In (Ii = 1250 A). The 100% N conductor protection means the neutral pole is fully rated and trips simultaneously with the phase poles — required on 4-wire systems where the neutral carries unbalanced load current and must be switched, not just connected. The ATFM designation indicates the trip unit is adjustable thermal, fixed magnetic.
OEM variant and deployment context
This order code carries the -ZD00 suffix, a Siemens OEM variant configured for DC Power applications in China. The 4-pole form factor suits it for three-phase + neutral distribution panels, UPS output breakers, or generator paralleling gear where neutral switching and protection are mandatory. The 70 kA class H rating gives selectivity headroom downstream of a larger main breaker.
No spare, no sleep — this one is worth keeping one in the cabinet if the install is remote or the line has no redundancy.