The Siemens 3VA1020-3ED36-0KH0 is a 3-pole IEC frame 100 circuit breaker with a 20 A fixed thermal-magnetic overload (TM210) and a fixed short-circuit protection set at 16 x In. Breaking capacity is 25 kA at 415 V (class N), which means it can safely interrupt fault currents up to that level on a 415 V line without needing an upstream breaker to take the hit — useful for panel selectivity where the main is a higher-rated unit.
What the ratings mean for fit
The 20 A fixed overload (Ir = 20 A) means this breaker is sized for a 20 A continuous load — no adjustment range, so the circuit it protects must be designed around that exact ampacity. The short-circuit trip at 16 x In (320 A magnetic) is fixed as well, so it's suited for loads with moderate inrush, like general distribution or small motor circuits, but not for high-inrush transformers where nuisance tripping could occur. The shunt trip (STL) operates on 220-250 V DC or 208-277 V AC, letting you remotely trip the breaker from an emergency-stop circuit or a PLC output. Two auxiliary switches (HQ) and one trip alarm switch (HQ) provide status feedback — useful for a panel builder wiring a remote indication or a safety chain.
Panel integration notes
Clamp-type connections on the line and load terminals accept copper conductors typical for a 20 A circuit. The 3VA1 frame fits standard DIN-rail mounting in a distribution board or control panel. The shunt trip and auxiliary switches add wiring points, so plan for terminal-block space and wireway fill in the enclosure layout.