What this 3VA2 breaker brings to the panel
The Siemens 3VA2340-6JP42-0AJ0 is a 4-pole IEC frame 400 circuit breaker with an 85 kA breaking capacity at 415 V — class H, meaning it handles high fault currents common in industrial distribution without needing a current-limiting upstream device. The ETU550 trip unit gives you LSI protection: long-time (overload) adjustable from 160 A to 400 A, short-time (selective) from 0.6x to 10x In, and instantaneous from 1.5x to 10x In. That adjustable short-time delay is what lets you coordinate downstream breakers for selectivity — a key requirement for plant engineers who want only the faulted branch to open, not the whole feeder. The N-conductor protection is adjustable from OFF to 100%, so you can match the neutral sizing to the load — useful on 4-wire systems where the neutral carries harmonics from single-phase loads. The built-in 2 auxiliary changeover switches and 1 trip alarm changeover switch give remote status without adding external relays, which saves DIN rail space and wiring time.
Integration notes for panel OEMs and field installers
The nut keeper kit (included per the description) keeps the busbar screws from dropping into the panel during assembly, a small but real time-saver on a production line. For commissioning engineers: the ETU550 is field-adjustable; the rotary dials for Ir, Isd, and Ii are accessible without removing the cover, so you can dial in the coordination study values on-site with a screwdriver. No special software needed.