What it is and what it does
The Siemens 5SL6220-6MB is a 2-pole miniature circuit breaker from the SENTRON 5SL series, rated 20 A at 400 V AC with a B tripping characteristic and a 6 kA breaking capacity per EN 60898. The B-curve means it trips between 3 and 5 times rated current — suited for resistive and general-purpose loads where inrush is moderate, not for motor starting or transformer primaries. Rated operational current holds at 20 A up to 30 °C ambient; above that, per standard thermal derating, the continuous load must be reduced.
Voltage and breaking capacity
Single-phase operation is rated at 250 V AC; multi-phase operation at 400 V AC, with a maximum of 440 V AC across the poles. The 6 kA breaking capacity per EN 60898 is the standard domestic and light-commercial fault level — adequate for most residential and infrastructure sub-distribution boards, but verify against the prospective short-circuit current at the installation point. DC rating is 72 V maximum — usable in some control circuits but not a primary DC breaker.
Physical fit and panel integration
Occupies 2 modular width units (36 mm) on a DIN rail. Depth is 76 mm, installation depth 70 mm. Mounting position is any — no derating for horizontal or inverted orientation. IP20 with connected conductors — suitable for enclosed distribution boards, not for wet or washdown environments. Sealable design allows locking in the OFF position for lockout/tagout procedures.
Environmental and compliance notes
Halogen-free and silicon-free construction — relevant for installations where outgassing or silicone contamination must be avoided (e.g., near sensitive optics or clean-room zones). Rated for ambient temperatures from -40 °C to 75 °C, covering most indoor and sheltered outdoor enclosures. Mechanical service life is 10,000 switching cycles typical.