Why Choose the Mersen A4J400 Amp-Trap Fuse?
The Mersen A4J400 is a high-performance Class J fast-acting current-limiting fuse designed to protect industrial and commercial electrical systems against damaging overcurrents and short circuits. As part of the established Mersen Amp-Trap A4J series, it provides rapid fault interruption for feeder circuits, switchboards, panelboards and high-current electrical equipment.
The A4J400 delivers effective current limitation by restricting the peak current and total let-through energy that can reach downstream components during a fault. This helps reduce thermal and mechanical stress on cables, busbars, switches and other electrical equipment, supporting improved system safety and minimising the risk of costly equipment damage.
With a rated current of 400 A, a 600 V AC rating and a 300 V DC rating, the Mersen A4J400 is suitable for demanding AC and DC power-distribution applications. Its Class J rejection dimensions help prevent substitution with fuses that have unsuitable voltage, interrupting or current-limiting characteristics.
Key Advantages
- Fast-acting Class J fuse for industrial circuit protection.
- 400 A current rating for high-current feeders and equipment.
- 600 V AC and 300 V DC ratings for AC and DC systems.
- Current-limiting operation helps reduce damaging fault energy.
- 200 kA AC interrupting rating for high-fault-current installations.
- Class J rejection dimensions help prevent unsuitable fuse substitution.
Key Features
- Mersen Amp-Trap A4J series.
- 400 A rated current.
- 600 V AC voltage rating.
- 300 V DC voltage rating.
- Fast-acting current-limiting performance.
- Blade-terminal construction.
- High interrupting capacity for demanding electrical systems.
- Compatible with correctly rated Class J fuse holders.
Reliable Protection for High-Current Electrical Systems
Current-limiting fuses such as the Mersen A4J400 interrupt fault currents rapidly before they can reach their maximum prospective level. By restricting peak current and total let-through energy, the fuse helps protect downstream equipment from excessive heat, electromagnetic forces and other damaging effects associated with short-circuit conditions.
The A4J series is designed for installations requiring fast operation, high interrupting capacity and dependable current limitation. Its Class J format supports safe fuse selection while providing reliable protection for industrial switchboards, distribution panels, bus systems and machinery installations.
Typical Applications
- Industrial feeder circuits.
- Panelboards and switchboards.
- Load centres and power-distribution equipment.
- Bus duct and busbar systems.
- Lighting and heating circuits.
- Industrial machinery and general-purpose electrical loads.
