The Siemens SENTRON 5SY4104-6CC is a 1-pole miniature circuit breaker (MCB) with a B tripping characteristic, rated 4 A at AC and a 10 kA breaking capacity per EN 60898.
The 4 A rating is the continuous current at 35 °C; at 50 °C it derates to 3.5 A, and at 55 °C to 3.37 A — factor that into panel ambient if the breaker sits near heat sources.
The 18 mm width (1 modular unit) and 70 mm installation depth leave room for adjacent breakers and wiring troughs in a crowded enclosure. Sealable terminals are standard, which matters for panel builders who need to lock out adjustment after commissioning.
Environmental range
Rated for -40 °C to 75 °C ambient, with humidity derating: max 95% RH up to 55 °C, tapering to 35% RH at 75 °C.