What this breaker is and what the ratings mean
The Siemens 3VA1116-5EF42-0AH0 is a 4-pole IEC frame 160 molded-case circuit breaker with breaking capacity class M, rated Icu = 55 kA at 415 V AC. That interrupting rating means it can safely clear a fault up to 55 kA without rupturing — sufficient for most industrial secondary-distribution switchboards where the prospective short-circuit current sits in that range. The TM240 thermal-magnetic trip unit gives overload protection adjustable from 112 A to 160 A (Ir), and short-circuit pickup (Ii) adjustable 5 to 10 times the rated continuous current In = 160 A. For a panel builder, this means you set Ir to match the cable or busway ampacity, and Ii to coordinate with downstream breakers — typically 5x for general loads, 10x for motor circuits with higher inrush.
Deployment context and integration
This breaker mounts on a DIN rail or directly onto a mounting plate inside an enclosure. The nut keeper kit holds the line and load lug nuts captive during wiring — a time-saver when you're landing 160 A cables in a tight gland plate. The N conductor is unprotected (solid neutral), so this is a 3-pole + N configuration; the neutral bar passes through without overcurrent protection. Two auxiliary switches (HQ) and one trip alarm switch (HQ) are factory-fitted, giving remote status for PLC or SCADA inputs without additional wiring modules.