What this breaker carries
The Siemens 3VA1150-5EE32-0AA0-ZD00 is a 3-pole IEC frame 160 molded-case circuit breaker with a 55 kA interrupting capacity at 415 V — class M, meaning it handles moderate fault levels typical of industrial distribution panels without needing a current-limiting upstream device. The TM220 thermal-magnetic trip unit gives you adjustable overload protection from 35 A to 50 A (set via the Ir dial) and a fixed short-circuit pickup at 10 times the In rating, so 500 A magnetic trip for the 50 A version. That 55 kA Icu at 415 V is the maximum short-circuit current the breaker can safely interrupt once. If your available fault current at the panel is lower, you get full selectivity with downstream breakers — but if it's higher, you'll need a current-limiting fuse or a higher-class breaker upstream. The ATFM designation means it's a standard distribution breaker, not a motor-circuit protector; the thermal curve is shaped for cable and busbar protection.
Where it fits
This breaker snaps onto a standard DIN rail inside an IP54 or IP65 enclosure — common for machine-tool panels, conveyor control cabinets, or pump stations. The frame 160 footprint accepts plug-in accessories (auxiliary contacts, shunt trips, undervoltage releases) that clip into the left side without extra wiring space. The nut keeper kit in the ZD00 suffix is for DC Power OEM builds in China — it keeps the terminal nuts captive during transport and vibration, a detail that saves a field-service call if a nut drops into a live panel.