The Siemens 3VA1225-4EE42-0AA0-ZD00 is a 4-pole IEC frame 250 molded case circuit breaker rated for line protection. It carries a 36 kA ultimate breaking capacity (Icu) at 415 V AC, placing it in breaking capacity class S — sufficient for most secondary distribution panels and motor control center infeeds where fault levels stay under that threshold. Overload protection is handled by a TM220 thermal-magnetic trip unit with an adjustable continuous current rating (Ir) from 175 A to 250 A, set by the user to match the downstream load. Short-circuit protection is fixed at Ii = 10 × In, meaning the magnetic trip fires at 2500 A. The N conductor is unprotected — this breaker is configured for a 3-pole plus solid-neutral application, not a fully protected 4-pole scheme.
What the ratings mean for fit
The 36 kA Icu at 415 V is the key coordination number. In a panel with a transformer or utility feed that can deliver a prospective fault current of, say, 25 kA, this breaker clears it without needing a current-limiting upstream device. If your available fault current exceeds 36 kA, you need a higher-class frame (class H or L in the 3VA family) or a fused switch ahead of it. The Ir adjustment range (175 A to 250 A) lets you dial in the overload pickup for a 200 A feeder or a 225 A bus — you are not locked into a fixed rating. The fixed Ii at 10× In means the magnetic trip is not adjustable; if the downstream load has a high inrush (large transformers or capacitor banks), verify that 2500 A instantaneous pickup does not cause nuisance tripping on energization.
Integration notes
The 3VA1 frame mounts on a DIN rail or can be screw-mounted to a backplate. It occupies a standard 4-pole width in the panel; the nut keeper kit (included per the OEM variant) simplifies DC bus bar connections on the line side. The unprotected N conductor means the neutral bar passes through the breaker without a pole — verify your system grounding scheme before wiring.