The Siemens 5SL6620-7MB is a SENTRON miniature circuit breaker — a 4-pole unit (3P+N) with a C-trip curve, rated 20 A at 400 V AC. The 6 kA breaking capacity per EN 60898 is the standard for residential and light-commercial distribution boards; it clears a bolted fault up to 6 kA without welding the contacts or cascading damage upstream. The C-curve means the magnetic trip fires between 5× and 10× rated current — 100 to 200 A — so it handles motor inrush from pumps or small compressors on a lighting or general-purpose circuit without nuisance tripping.
Where it goes and how it fits
The 4-module-width body (72 mm wide) occupies four 18 mm slots in a consumer unit or sub-distribution board. Installation depth is 70 mm, with an overall depth of 76 mm including the front face — check clearance to the enclosure door or cover.
What it handles — environmental and electrical
The 1.9 W power loss per pole at rated current adds up to about 7.6 W total for all four poles — negligible in a ventilated enclosure but worth noting if the board is sealed and densely populated.