Siemens SENTRON 5SL4220-7RC — 2-pole C-curve MCB, 20 A, 10 kA
The Siemens SENTRON 5SL4220-7RC is a 2-pole miniature circuit breaker rated 20 A with a C tripping characteristic and a 10 kA breaking capacity per EN 60898 at 415 V AC. The 10 kA interrupting rating at 415 V AC means it can safely interrupt fault currents up to that level on a 415/240 V three-phase system or a 240 V split-phase service. Rated for multi-phase operation up to 440 V AC and single-phase up to 250 V AC, with a DC rating of 72 V maximum. The 2-pole design switches both line conductors, suitable for 2-wire single-phase or two legs of a three-phase circuit.
Physical integration and environment
Dimensions are 18 mm wide, 90 mm high, and 76 mm deep — a single 1 MW unit that clips onto standard DIN rail.
This is the standard residential/commercial interrupting rating for most European distribution boards. Power loss: 2.17 W per pole in hot operating state at rated current. Mechanical service life: 10,000 operating cycles typical. This is adequate for normal switching duty in a distribution board; for frequent switching applications (e.g., as a disconnect under load), consider a contactor instead.