The Siemens 5SL6220-6 is a SENTRON 2-pole miniature circuit breaker (MCB) with a B tripping characteristic, rated at 20 A and a 6 kA breaking capacity per both EN 60898 and IEC 60947-2. It occupies 2 modular width units on a DIN rail, with a 36 mm width, 76 mm depth, and 90 mm height — the standard footprint for a 2-pole MCB in a residential or light-commercial distribution board.
Thermal derating and installation constraints
Rated current holds at 20 A up to 30 °C ambient. At 40 °C it derates to 18.79 A, at 45 °C to 18.4 A, and at 55 °C to 16.8 A — a roughly 16% drop from nameplate to the top of the operating range. The MCB carries IP20 protection with connected conductors, so it belongs inside a closed enclosure, not in a washdown or outdoor location. Mounting position is unrestricted, which simplifies layout in crowded panels. The unit is sealable and halogen-free, silicon-free — relevant for clean-room or sensitive-environment installs where outgassing matters.
That 6 kA rating places it in the standard-duty range for final subcircuits in residential and small commercial boards. If your fault-current study shows more than 6 kA available at the panel, step up to a 10 kA or 15 kA rated MCB — the 5SL series has higher-breaking siblings. The energy limitation class is 3, meaning it limits let-through energy well enough to protect downstream wiring within its rating.
The MCB carries an overvoltage category III rating and pollution degree 2 — standard for fixed-installation distribution boards. It is designed for residential buildings and infrastructure per the manufacturer's suitability designation. The product designation follows EN 61346-2 and IEC 81346-2 function code F (protective device).