The Schneider Electric A9N21389 is a DT40N miniature circuit breaker from the ProDis range, rated 32 A with a C-curve magnetic trip threshold of 5 to 10 times In. Breaking capacity is 6 kA Icn at 400 V AC per EN/IEC 60898-1, and 10 kA Icu at 400–415 V AC per IEC 60947-2. The dual rating means this breaker is certified for both the domestic-standard (60898-1) and industrial-standard (60947-2) frameworks — useful when the same panel feeds both a residential riser and an industrial sub-distribution board, or when a consultant specifies 60947-2 for the SCCR headroom.
Construction and integration
Three-pole, three protected poles, thermal-magnetic trip unit. Clips onto DIN rail (EN 60715) — 6 module pitches at 9 mm each, so it occupies 54 mm of rail width. Tunnel terminals accept 0.33–10 mm² flexible or 0.75–16 mm² rigid on both upstream and downstream sides; strip length 13 mm, tighten to 2 N·m. IP20 finger-safe terminals, suitable for enclosure use where the front panel provides the next level of protection. Toggle control with ON/OFF local indication.
Rated for 10,000 electrical cycles and 20,000 mechanical cycles.