The C25N6TM125 is a Schneider Electric ComPacT NSX250N moulded-case circuit breaker with a 125 A TM-D thermal-magnetic trip unit, 4 poles, and a 50 kA interrupting rating at 415 V AC. That N breaking capacity code means it handles 50 kA Icu at 380–440 V — enough for most industrial distribution boards downstream of a transformer. The TM-D trip gives you fixed thermal overload protection (L) and fixed magnetic short-circuit protection (I), no adjustment dials, which makes it a straight swap-in for a BOM that needs a no-fuss 125 A feed.
Breaking capacity — the number that matters for fault protection
The C25N6TM125 carries a 50 kA Icu at 380/415 V AC and 440 V AC per IEC 60947-2. At 220/240 V it jumps to 90 kA Icu; at 660/690 V it drops to 10 kA Icu. Also listed with UL 60947-4-1 ratings: 85 kA at 240 V, 50 kA at 480 V, 15 kA at 600 V — so it's dual-certified for North American and IEC installs.
Neutral is on the left, and the toggle handle gives positive on/off indication. Electrical durability is 20,000 cycles at 440 V at rated current, 10,000 at 690 V — good for a main disconnect that sees a few operations a day.