Panel fit and ratings
The Siemens SENTRON 5SJ3625-7 is a 4-pole miniature circuit breaker (3P+N) rated 25 A with a C-curve trip characteristic, meaning it trips at 5 to 10 times rated current — standard for motor and general-purpose branch circuits where moderate inrush is expected. Breaking capacity is 4.5 kA per EN 60898 and IEC 60947-2, which covers typical commercial and light industrial panel fault levels. Rated voltage is 400 V AC, insulation voltage 440 V. The 25 A C-curve is the default choice for mixed resistive and inductive loads in distribution subboards. Mounts on DIN rail with any orientation; installation depth is 70 mm. The 4 width units (72 mm) occupy four modular spaces on the rail — confirm your enclosure fill factor before committing. Conductor range accepts solid or stranded from 0.75 to 25 mm², so it handles standard building wire sizes without adapters.
What the ratings mean for fit
The C-curve (tripping between 5× and 10× In) is the workhorse for general-purpose loads — lighting, small motors, transformers, and control circuits. For a 25 A frame, expect the magnetic trip to hold steady through a motor start surge up to roughly 250 A before instantaneously opening. The 4.5 kA SCCR at 400 V is sufficient for most commercial and light industrial service entrances; if your available fault current exceeds that, you need an upstream current-limiting device or a higher-rated breaker. Overvoltage category 3 means it is rated for fixed-installation use downstream of the main distribution board. The 20 000 mechanical switching cycles typical service life is adequate for normal switching duty; for frequent switching (e.g., heater cycling), consider a contactor instead. Ambient temperature range is -20 to +45 °C; above 45 °C derate per the thermal curve. Storage range extends to -40 to +75 °C. The IP20 rating with connected conductors means it is protected against finger contact but not against moisture — install inside a rated enclosure in wet or dusty environments.