The 5SY4340-7: For UL 1077 listed supplementary protection applications, the interrupting rating is 5 kA at 400 V AC.
What the C-curve and voltage ratings mean for your circuit
It will not nuisance-trip on a motor start but clears fast on a hard short. Operating voltage is 400 V AC (440 V max single- or multi-phase) and 60 V DC (72 V DC max) — the DC rating is notably lower, so if you need DC branch protection, confirm the voltage stays within the 60 V nominal ceiling. That dual-standard approval simplifies BOM approval across EU and NAFTA projects.
The 70 mm installation depth (76 mm overall) fits standard enclosures. IP20 protection with connected conductors.