What this 4-pole D-curve MCB is for
Occupies 4 width units (72 mm wide, 90 mm tall, 76 mm deep with 70 mm installation depth).
The D tripping characteristic is the key selector: it allows 10–20× rated current before magnetic trip, so it won't drop out on motor inrush or transformer energization. Rated 400 V AC for multi-phase operation, 440 V AC for single-phase or multi-phase use. Mechanical endurance is 10,000 switching cycles typical. The magnetic-only design means no thermal bimetal — it responds to overcurrent only, not overload; pair it with a separate overload relay for motor protection.