The Siemens 5SY4115-5 is a 1-pole SENTRON miniature circuit breaker rated 1.6 A at AC with a tripping characteristic A — the most sensitive curve, tripping between 2 and 3 times rated current. That makes it the right choice for protecting semiconductor circuits, control transformers, or instrumentation loops where standard B- or C-curve breakers would let through too much energy before opening. Both standards are listed, so the breaker carries dual certification for the same installation. At 40 °C ambient the continuous rating derates to 1.52 A; at 50 °C it drops to 1.44 A, and at 60 °C to 1.36 A. If the panel runs hot — near a drive or transformer — size up or verify the load stays under the derated value.
Installation depth is 70 mm, leaving clearance behind the rail for wiring. The top and bottom terminals are combined (screw + clamp), accepting both solid and stranded copper. Touch protection is built in, so no additional finger-safe covers are needed on the line side.