The Siemens 3VA1340-4GF42-0AA0-ZD00 is a 4-pole IEC frame 400 circuit breaker from the 3VA1 series, rated at In=400A with a breaking capacity of Icu=36kA at 415V (class S). The TM240 ATAM trip unit provides adjustable overload protection (Ir=280A...400A) and short-circuit protection (Ii=5...10 x In), plus 100% N conductor protection.
The adjustable Ir band (280A to 400A) lets you fine-tune the thermal trip to match the actual load, avoiding nuisance trips while still protecting the cable. The Ii range of 5 to 10 times In (2000A to 4000A) sets the magnetic trip threshold for short-circuit protection — a wider band than fixed-setting breakers, useful when coordinating with downstream devices.
Deployment context
The nut keeper kit simplifies installation on busbars in OEM builds. The DC Power OEM designation suggests it's intended for DC power distribution applications, where the 100% N conductor protection is relevant for ungrounded or high-resistance-grounded systems.