What this 400 A MCCB does on a distribution board
That fixed trip gives you short-circuit (magnetic) and overload (thermal) protection in one package — no field-adjustable long-time pickup, so it's a straight swap-in for a 400 A distribution feeder or large motor branch circuit where you don't need tweaking. Breaking capacity hits 40 kA Icu at 220/240 V AC and 36 kA Icu at 380/400 V AC (50/60 Hz) per EN/IEC 60947-2. The 36 kA at 400 V covers typical transformer-fed fault levels without cascading upstream.
Fixed backplate mount with a 45 mm connection pitch. Neutral position is left, so plan your bus layout accordingly. Dimensions: 257 mm high, 150 mm wide, 108 mm deep. IP40 enclosure (finger-safe, no water protection) and IK07 impact resistance — fine inside a locked panel, not for outdoor or washdown locations.
The TM-D trip holds a fixed 1 In long-time pickup, so it carries 400 A indefinitely and trips on overload above that. Electrical endurance: 12000 cycles at 415 V at In/2 per EN/IEC 60947-2. Mechanical durability is 15000 cycles. That's typical for a distribution breaker — not rated for frequent switching like a contactor, but fine for infrequent on/load-off operation. Category A (no intentional short-time delay) means it's not designed for selective coordination downstream — use it as a main or feeder breaker where you rely on upstream devices for backup protection.