What this MCB is and where it fits
The Siemens 5SL4306-8 is a 3-pole miniature circuit breaker from the SENTRON family, rated 6 A at 400 V AC with a D tripping characteristic. It delivers 10 kA breaking capacity certified under both EN 60898 and IEC 60947-2, meaning it safely clears faults up to that level without cascading upstream. The D-curve (10–20× In) is sized for loads with high inrush — motor starters, transformers, or discharge lighting — where a B or C curve would nuisance-trip on startup. It occupies 3 modular width units (54 mm) on a DIN rail and accepts any mounting position, so panel layout is flexible.
Thermal derating — the real continuous current
At 30 °C ambient the breaker carries its full 6 A rating. At 40 °C that drops to 5.76 A, at 45 °C to 5.64 A, and at 55 °C to 5.37 A. If the panel runs warm — typical for a densely packed enclosure — the continuous load must be sized against the derated value, not the nameplate 6 A. The 5SL4306-8 is halogen-free and silicon-free, which matters for clean-room or sensitive-environment installations where outgassing can contaminate contacts or optics.
Lifecycle and sourcing posture
This is a current-production part — the lifecycle stage is active. It is sourced and quoted to order through independent distribution; availability and current pricing are confirmed at quote time against an RFQ. For compliance documentation, the SENTRON series carries the usual CE, RoHS, and REACH declarations; specific certificates for UL or IEC can be included with the quote.
Physical fit and panel integration
Width is 54 mm (3 MW), depth 76 mm, height 90 mm, with an installation depth of 70 mm. The IP20 rating applies with connected conductors — standard for a distribution board interior. Overvoltage category III and pollution degree 2 mean it is rated for fixed installation downstream of the main distribution board, not for outdoor or wet locations. Sealable terminals are provided, so the breaker can be locked in the off position for lockout/tagout procedures.