What this breaker is and what the ratings mean
The Siemens 3VA1120-5GD42-0AA0-ZD00 is a 4-pole IEC frame 160 molded-case circuit breaker with a 55 kA interrupting capacity at 415 V — that's the class M breaking capacity, meaning it clears faults up to that level without the arc flashing over, which is the spec that decides whether this breaker holds its downstream gear in a high-fault panel. Overload protection is fixed at 20 A (Ir = 20 A) via the TM210 thermal-magnetic trip unit; short-circuit pickup is set at 16 times the rated current (Ii = 16 x In), so it rides through motor inrush but trips fast on a bolted fault. The neutral conductor is protected at 100% — no derating for the N pole. This variant includes a nut keeper kit and is configured for DC Power OEM applications in China — the nut keeper keeps the terminal hardware from backing off under vibration in a panel that ships as a subassembly.
Sourcing and lifecycle
Pricing and availability are confirmed at quote time against an RFQ through independent distribution. The nut keeper kit and the China OEM configuration are part of the order code, so the quote matches exactly what lands on the dock.