The Siemens 3VA1140-4EE32-0AA0-ZD00 is a 3-pole IEC frame 160 circuit breaker with a 40 A rated current (In) and a breaking capacity class S rated at 36 kA at 415 V. It's fitted with a TM220 thermal-magnetic trip unit — the ATFM designation — giving adjustable overload protection from 28 A to 40 A (Ir) and a fixed short-circuit pickup of 10 x In (Ii = 400 A). The nut keeper kit on this variant is specified for a DC Power OEM build in China, so if you're stocking a replacement for that exact line, the hardware matches the panel's captive fasteners.
What the Ratings Mean for Fit
The 36 kA Icu at 415 V puts this in breaking capacity class S — it's rated to safely interrupt fault currents up to that level under IEC 60947-2, which is the standard for low-voltage switchgear. For a 40 A feeder on a 415 V three-phase supply, that's ample margin for most industrial panelboards. The adjustable overload (Ir = 28–40 A) lets you fine-tune the thermal pickup to the actual load cable without swapping the trip unit. The fixed magnetic trip at 10 x In (400 A) is a standard motor-starting characteristic — it rides through inrush without nuisance tripping on most pump and fan loads.
Panel Integration
Mounts on a standard DIN rail inside the enclosure. The 3VA1 frame is a compact 3-pole footprint — three modules wide — so it fits a 9-module or larger distribution board without crowding the gland plate. The nut keeper kit means the panel builder doesn't need a second set of hands to hold the busbar fasteners during assembly; that's a time-saver on repetitive builds.