What this 4-pole B-curve 25 A MCB delivers
The Siemens 5SJ6425-6 is a SENTRON 5SJ6 miniature circuit breaker rated 25 A at 400 V AC, 4-pole, with a B-curve tripping characteristic and 6 kA breaking capacity per EN 60898 and IEC 60947-2. Terminal capacity accepts solid or stranded conductors from 0.75 up to 25 mm², covering most distribution cable sizes up to 6 mm² tails and 16 mm² feeders.
Installation depth is 70 mm — verify enclosure depth against the back panel clearance, especially with gland plates or busbar systems behind the rail. The 4 width units (roughly 72 mm at 18 mm per unit) occupy the same footprint as any 4-pole 5SJ6 MCB; swapping a 2-pole unit like the 5SJ6220-6 would require a different rail layout and busbar arrangement. Sealable terminals (yes) allow panel builders to lock the cover after wiring — useful for installations requiring tamper-evident metering or utility isolation. Touch protection is integrated per the listing.