What this 1.6 A C-curve MCB is for
The Siemens 5SY5115-7 is a 1-pole miniature circuit breaker from the SENTRON 5SY5 series, rated 1.6 A with a C tripping characteristic. That C-curve means it holds through inrush up to 5–10× rated current before the magnetic trip fires — sized for mixed resistive and light inductive loads like control transformers, contactor coils, or small power supplies where the startup surge is higher than a B-curve would tolerate. Rated 400 V AC and 220 V DC, with a breaking capacity of 10 kA per EN 60898 and 15 kA per IEC 60947-2 at DC. That 15 kA DC rating matters if you're protecting a DC bus or battery-backed circuit — most 1-MW MCBs stop at 10 kA DC. Pollution degree 3 and overvoltage category III mean it's rated for the industrial panel environment, not just residential distribution boards.
Panel fit and mounting
Snaps onto DIN rail via the quick-assembly system — 18 mm width (1 MW), 76 mm depth, 90 mm height. Mounting position any, so it works horizontally in a shallow enclosure as long as the conductors don't block the vent path. Installation depth 70 mm leaves 6 mm behind the rail for wiring. Top and bottom combined terminals accept the same wire gauge, which speeds up panel wiring when you're running a common bus bar through the bottom.
Environmental and compliance notes
Halogen-free and silicon-free construction — relevant for clean-room or semiconductor-adjacent panels where outgassing contaminates optics or contacts. Touch protection built into the terminals. Ambient range -40 °C to 75 °C, with humidity derating above 55 °C: max 95% RH at 55 °C, dropping to 35% at 75 °C. That covers most non-condensing industrial enclosures.