The Siemens SENTRON 5SL6220-7BB is a 2-pole miniature circuit breaker (MCB) with a C tripping characteristic, rated 20 A at 400 V AC, 50 Hz.
At 20 A and 400 V AC, this MCB handles a single-phase or split-phase branch up to that current. Thermal derating is published for ambient temperatures from 30 °C to 55 °C: 20 A at 30 °C, 18.94 A at 40 °C, 18.4 A at 45 °C, and 17.24 A at 55 °C (–). If the panel runs warm, apply these figures — the breaker's thermal element responds to ambient heat, so a 20 A breaker in a 55 °C enclosure effectively behaves like a 17 A device.
Snap-mounts onto standard DIN rail (EN 60715). Width is 36 mm (2 modular units,), depth 76 mm, height 90 mm, installation depth 70 mm. Mounting position is any — no restriction on orientation. Sealable — the toggle can be locked in the OFF position with a padlock hasp or seal wire, useful for lockout/tagout. Touch protection is integrated. Halogen-free and silicon-free construction reduces toxic fume risk in a fire and avoids silicone outgassing that can contaminate contacts in sensitive environments.