DC-rated MCB for 440 V rail protection
The Siemens 5SL5205-7RC is a 2-pole miniature circuit breaker from the SENTRON 5SL series, rated 0.5 A with a C tripping characteristic. It is designed specifically for DC applications up to 440 V with a 10 kA breaking capacity — not a general-purpose AC breaker pressed into DC service. The C-curve means magnetic trip occurs at 5 to 10 times rated current, suited for moderate inrush loads like control transformers or small DC power supplies where nuisance tripping on startup needs to be avoided.
Panel fit and integration
Occupies 2 modular width units (36 mm) on standard DIN rail, installable in any mounting position. Depth of 76 mm leaves 70 mm required behind the panel surface — verify enclosure depth before wiring. IP20 with connected conductors; intended for residential and infrastructure distribution boards, not for wet or dusty environments. Halogen-free and silicon-free construction matters when the breaker sits in enclosed spaces where outgassing from a fault event could affect nearby electronics.