The Siemens 3VA1140-5EE32-0AA0-ZD00 is a 3-pole IEC frame 160 circuit breaker with a 55 kA breaking capacity at 415 V (class M). It carries a TM220 thermal-magnetic trip unit with a 40 A nominal rating (In), adjustable overload protection (Ir) from 28 A to 40 A, and a fixed short-circuit protection (Ii) at 10× In. The ATFM designation indicates the trip curve and accessories configuration. A nut keeper kit is included for DC Power OEM installations in China.
What the ratings mean for fit
The 55 kA Icu at 415 V is the ultimate short-circuit breaking capacity — the breaker can safely interrupt a fault current up to that level once and remain functional. Class M (medium breaking capacity) is the standard choice for most industrial distribution panels; it sits between standard (S) and high (H) classes. The TM220 thermal element provides inverse-time overload protection for cables and moderate motor starts, while the magnetic element (Ii = 10× In, or 400 A) handles short-circuits. The adjustable Ir (28–40 A) lets you fine-tune the overload threshold to match the downstream load without swapping the breaker.