Circuit breaker 3VA1 with shunt trip and auxiliary switches
The Siemens 3VA1220-5MH32-0HH0 is a 3-pole IEC molded-case circuit breaker in the 3VA1 frame, rated 200 A with a 55 kA breaking capacity at 415 V (class M). It is configured for starter protection with a TM120M thermal-magnetic release, but note: this variant omits the overload protection element — it provides short-circuit protection only, with an adjustable instantaneous trip Ii = 6–14 × In. The breaker ships with a shunt trip (STL) rated 12–30 V DC or 24 V AC 50/60 Hz, two auxiliary switches (HQ), and one trip alarm switch (HQ). A nut keeper kit is included for secure panel mounting.
What the ratings mean for fit
The 55 kA Icu at 415 V is the ultimate breaking capacity — the maximum fault current the breaker can safely interrupt once. For selectivity studies, the instantaneous trip range of 6–14 × In (1200–2800 A) lets you coordinate with downstream devices. Because overload protection is absent, this breaker is intended for applications where a separate overload relay (e.g., a motor starter) handles thermal protection; the breaker itself only clears short circuits. The shunt trip allows remote tripping from a PLC or emergency-stop circuit, and the two auxiliary switches plus one alarm switch provide status feedback to a control system.