The Siemens 5SL4320-7 is a SENTRON miniature circuit breaker, 3-pole, with C-curve tripping, rated 20 A at 400 V AC and a 10 kA breaking capacity per both EN 60898 and IEC 60947-2. It occupies 3 modular width units (54 mm) on the DIN rail, depth 76 mm, and is rated for residential and infrastructure panels.
What the ratings mean for fit
The C-curve (tripping characteristic class C) means magnetic trip between 5 and 10 times rated current — standard for general-purpose lighting and small motor loads where inrush isn't extreme. The 10 kA breaking capacity at 400 V AC matches the typical domestic and light commercial fault level; if your panel's prospective short-circuit current exceeds that, step up to a higher-rated breaker. Rated for overvoltage category III and pollution degree 2, so it's suited for fixed installations inside a distribution board. Power loss per pole is 2 W in hot operating state at rated current. Mechanical service life is 10 000 operating cycles typical — fine for most panel applications where the breaker sees infrequent manual switching.
Mounting and integration
Mounts in any position on a 35 mm DIN rail. Installation depth is 70 mm, overall depth 76 mm. The 54 mm width (3 modular units) is standard for a 3-pole MCB. Sealable, halogen-free, silicon-free — relevant for clean-room or harsh-environment specs. IP20 with connected conductors, so it's not for wet locations without an outer enclosure. Supplementary devices (auxiliary switches, shunt trips, alarm contacts) can be added via the product extension feature — check compatibility with the 5SL range.