SENTRON 5SL6450-7MB — 4-pole C-curve MCB for 400 V distribution
The Siemens SENTRON 5SL6450-7MB is a 4-pole miniature circuit breaker rated 50 A at 400 V AC with a C tripping characteristic and a 6 kA breaking capacity according to EN 60898. It occupies 4 modular width units (72 mm) on a DIN rail, making it a direct fit for standard residential and infrastructure distribution boards where 4-pole protection of a three-phase plus neutral circuit is required.
What the ratings mean for fit
The C-curve (tripping characteristic class C) means the breaker trips at 5 to 10 times rated current — suited for circuits with moderate inrush, like lighting banks, small motor loads, or transformer-fed sub-distribution. The 6 kA breaking capacity at 400 V AC per EN 60898 tells you it can safely interrupt fault currents up to that level without upstream cascading; for higher prospective fault currents you'd step to a 10 kA rated unit like the 5SL4363-7 (3-pole) or 5SY5416-7 (4-pole, 10 kA). Power loss per pole is 3.5 W in hot operating state at rated current — at 4 poles that's 14 W total heat to dissipate inside the enclosure. Factor that into your thermal budget if the board is tightly packed or in a high-ambient location. Rated insulation voltage is 440 V AC for multi-phase operation, with an overvoltage category III and pollution degree 2 rating — standard for fixed-installation distribution boards downstream of the main service entrance. The IP20 protection class (with connected conductors) is typical for enclosed panel mounting; the sealable design allows the installer to lock the toggle position after commissioning.
Panel integration notes
Mounts on a 35 mm DIN rail per EN 60715 in any position. Depth is 76 mm (70 mm installation depth behind the panel surface), height 90 mm. The 4-module width (72 mm) matches the standard SENTRON 5SL series footprint — it shares the same housing as the 4-pole 5SY series breakers, so cutouts and busbar positions are consistent across the family. Supplementary devices (auxiliary switches, shunt trips, alarm contacts) can be installed on the right side.