B-curve trip and breaking capacity — what they mean for the panel
The Siemens 5SY5202-6 is a 2-pole miniature circuit breaker from the SENTRON 5SY5 series, carrying a B-curve tripping characteristic. That means the magnetic trip operates at 3 to 5 times rated current — it's the right choice for resistive and general-purpose loads where inrush is modest, not for motor-starting or transformer primaries that would nuisance-trip a B-curve. The interrupting rating is 10 kA per EN 60898 and 15 kA at DC per IEC 60947-2, so it handles fault currents up to those levels without cascading upstream. The 36 mm width takes two modular-width units on the DIN rail — standard for a 2-pole MCB in European-style panels.
Panel fit and environmental limits
Mounts in any position on a DIN rail via the quick-assembly system. Depth is 76 mm, installation depth 70 mm — that's the dimension that matters for enclosure depth clearance. IP20 with connected conductors means it's protected against finger contact but not against moisture; keep it inside a rated enclosure. Ambient range runs from -40 °C to 75 °C, so it's fine in unheated electrical rooms or outdoor-rated cabinets. Pollution degree 3 and overvoltage category III — suitable for fixed installations with conductive pollution, typical of industrial panels.
Approvals and compliance documentation
Rated to IEC / EN 60898-2 and UL1077 — the dual standard covers both IEC and North American acceptance for supplementary protection. Halogen-free and silicon-free construction, which matters for outgassing-sensitive environments like clean rooms or sealed enclosures with electronics. The sealable design allows the installer to lock the toggle position after commissioning — useful for tamper-proofing in accessible panels.