DC-rated miniature circuit breaker for 24 V to 220 V control circuits
The Siemens SENTRON 5SY5105-7CC is a 1-pole miniature circuit breaker rated 0.5 A with a C tripping characteristic, designed specifically for DC applications up to 220 V (max 250 V) with a breaking capacity of 10 kA per IEC 60947-2. This is not an AC-rated MCB pressed into DC service — the arc-quenching chamber and contact gap are optimized for DC interruption, which matters when you're protecting a 24 VDC PLC power supply or a 110 VDC control bus where an AC-rated breaker may not clear a fault. The C-curve (5-10x In) handles moderate inrush from contactor coils or small DC motors without nuisance tripping.
Panel fit and environmental ratings
Installation depth is 70 mm — the extra 6 mm is the front projection of the toggle and terminal cover. Mounts in any position, which simplifies layout in crowded enclosures.
Environmental tolerance and material compliance
Operating temperature range spans -40 °C to 75 °C, with humidity derating: 95% RH up to 55 °C, 55% RH up to 70 °C, 35% RH up to 75 °C. Vibration resistance per IEC 60068-2-6 covers ±1 mm at 5-25 Hz and 50 m/s² at 25-150 Hz — sufficient for installation on machinery or in mobile equipment. Halogen-free and silicon-free construction, which matters for clean-room or high-reliability environments where outgassing can contaminate contacts or optics.