The Siemens 3VA2450-5JP42-0AF0 is a 4-pole IEC frame 630 molded-case circuit breaker from the 3VA2 series, fitted with an ETU550 electronic trip unit for LSI (long-time, short-time, instantaneous) protection. Rated In=500A with overload protection adjustable from 200A to 500A, it delivers a breaking capacity of 55kA at 415V (class M), which means it can safely interrupt fault currents up to that level on a 415V three-phase line without cascading upstream — critical for maintaining selectivity in a distribution panel.
The nut keeper kit (included) retains the lug nuts during wiring — a detail that saves time when the panel builder is working in a tight gland plate area. The 4-pole configuration covers three-phase plus neutral, with the N-conductor protection adjustable from OFF to 100% of the phase setting.
The ETU550's LSI curve allows coordination downstream with smaller breakers or fused disconnects, giving the site electrical engineer the headroom to design a selective distribution scheme.