Siemens 5SL4420-7 SENTRON 4-pole MCB — C-curve, 20 A, 10 kA
The Siemens 5SL4420-7 is a 4-pole miniature circuit breaker from the SENTRON family, rated 20 A at 400 V AC with a C-curve trip characteristic and a 10 kA breaking capacity certified to both EN 60898 and IEC 60947-2. The C-curve means it trips between 5 and 10 times rated current — the standard choice for general-purpose loads like lighting, socket circuits, and small motor feeders where moderate inrush is expected. Snaps onto a DIN rail (4 modular width units, 72 mm wide) and fits any mounting position, with an installation depth of 70 mm and overall depth of 76 mm. Rated for 50/60 Hz supply and accepts multi-phase operation up to 440 V AC maximum; also carries a DC rating of 72 V maximum for those mixed panels.
Thermal derating and power loss
Full 20 A rating holds at 30 °C; at 40 °C derate to 18.94 A, at 45 °C to 18.4 A, and at 55 °C to 17.24 A — plan your panel ambient accordingly if you need the full rated current. Power loss runs 2 W per pole at rated current in hot operating state, so total 8 W for the 4-pole assembly — manageable in a standard enclosure but worth checking if you pack many breakers in a small box.
Lifecycle and sourcing
Supplementary devices (auxiliary switches, shunt trips, undervoltage releases) can be installed on the right side — the product extension interface is present.
Environmental and compliance
Rated for a -40 °C to +75 °C operating range, degree of pollution 2, overvoltage category III, and IP20 protection (with connected conductors). Halogen-free and silicon-free construction. Sealable design allows lockout/tagout in industrial panels. Energy limitation class 3 — fast arc extinction limits let-through energy downstream.