Protection and coordination for a 400 A feeder
The Siemens 3VA2440-8HM32-0AA0 is a 3-pole IEC molded case circuit breaker on a 630 A frame, fitted with an ETU330 electronic trip unit and rated In=400 A. The breaking capacity class L delivers Icu=150 kA at 415 V — that is the maximum fault current it can safely interrupt without upstream cascading, sized for high-fault industrial distribution where the available short-circuit current is substantial. The ETU330 provides LIG protection: long-time (overload) adjustable Ir=160…400 A, short-time (instantaneous) Ii=1.5…11 x In, and ground-fault Ig=0.2…1 x In with time delay tg=0.1/0.3 s. That ground-fault element is the key difference from a standard LI-only trip — it detects leakage to earth, which matters for personnel protection and equipment damage prevention on ungrounded or resistance-grounded systems.
Sourcing and lifecycle — active, built to order
Packaging is a single piece (265 x 165 x 170 mm). The unit is RoHS compliant since 01-04-14, with a REACH Article 33 notification for Lead (CAS 7439-92-1) above 0.1% w/w. Export control is AL:N / ECCN:9N9999.
Selectivity and coordination notes
The 3VA2 frame with 150 kA Icu at 415 V sits in the high-breaking-capacity tier of the 3VA family. For a 400 A feeder, the adjustable L and I settings let you coordinate downstream with smaller MCCBs or fused switches — the wide Ii range (1.5–11 x In) gives room to ride through motor inrush while still clearing a bolted fault. The ground-fault element adds a separate coordination layer for earth faults, which a standard thermal-magnetic breaker cannot do.