What it is and what it does
The Siemens 5SL6414-7 is a 4-pole SENTRON miniature circuit breaker (MCB) with a C tripping characteristic, rated at 0.3 A at 400 V AC. It breaks fault currents up to 6 kA per both IEC 60898 and IEC 60947-2 — the standard for residential and infrastructure branch-circuit protection. The C-curve means it trips between 5 and 10 times rated current, sized for moderate inrush loads like small lighting banks or control transformers where a B-curve would nuisance-trip but a D-curve would be too slow.
What the ratings mean for fit
The 0.3 A rating is the continuous current at 30 °C; at 40 °C it derates to 0.29 A, at 45 °C to 0.27 A, and at 55 °C to 0.26 A. If your panel ambient runs above 30 °C, size the upstream protection for the derated value, not the nameplate. The 6 kA breaking capacity at 400 V AC covers most residential and light commercial fault levels — if your available fault current exceeds that, you need a current-limiting upstream device or a higher-rated breaker. Overvoltage category III and pollution degree 2 confirm it is rated for fixed-installation downstream of the utility meter.
Mounting and integration
Occupies 4 modular width units (72 mm wide) on a standard DIN rail. Depth is 76 mm, installation depth 70 mm — verify your enclosure depth clears the wiring gutters. Mounting position is any orientation. The IP20 rating (with connected conductors) means it is for indoor panel use only, not washdown or outdoor. Touch protection is built in on the line side. No neutral conductor switching — this is a 4-pole breaker for 3-phase + neutral protection where the neutral is switched only by a separate device or left solid.
Environmental and compliance
Halogen-free and silicon-free construction. Rated for ambient temperatures from -40 °C to 75 °C, with periodic exposure to +55 °C at up to 95% humidity. Sealable — the toggle can be locked in the off position for lockout/tagout. Mechanical service life is 10 000 operating cycles typical. Energy limitation class 3 means it limits let-through energy to a moderate level, appropriate for the 6 kA fault rating.