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MERSEN FUSE 600V 400A CLASS J FUSE A4J400
Fast-acting Class J fuse rated for 600VAC and 300VDC up to 400A with Amp-Trap® technology for superior circuit protection.
£151.47
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.
Technical Specifications
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| Current | 400 A | |
|---|---|---|
| Voltage | 600 V | |
| Fuse Type | UL class | |
| Fuse Class | Fast acting | |
| Item number | A4J400 | |
| Description | Fuse A4J - Class J - Fast-Acting 600VAC 300VDC 400A Blade Amp-Trap® | |
| EAN/UPC Code | 782001960452 | |
| Rated voltage AC UL | 600 V | |
| Rated voltage DC UL | 300 V | |
| Frequency (Hz) | 50/60 Hz | |
| Ampere Rating | 400 A | |
| AC or DC | AC/DC | |
| Fuse Class | Class J | |
| Speed/Characteristic | Fast-Acting | |
| Mounting | Clip | |
| AC Max I.R./Breaking Capacity | I1: 200 kA | |
| Connection/Terminal Material | Brass Alloy | |
| Connection/Terminal Type | Blade | |
| Product Diameter | 54 mm | |
| Product Length | 181.1 mm | |
| Sell Pack Quantity | 1 EA | |
| Sell Pack Weight | 0.8346 kg | |
| Sell Pack Width | 53.8 mm | |
| Sell Pack Length | 53.8 mm | |
| Sell Pack Height | 184.1 mm | |
| Product group | Low Voltage UL/CSA Fuses | |
| Body/Insulating Material | GMG | |
| Product Weight | 0.7938 kg | |
| HS Code | 85361090 | |
| Country of Manufacture | Mexico |
Frequently Asked Questions
What is the Mersen A4J400 used for?
The Mersen A4J400 provides fast-acting overcurrent and short-circuit protection for industrial feeder circuits, switchboards, panelboards and high-current electrical equipment.
What is the current rating of the A4J400 fuse?
The A4J400 has a rated current of 400 A.
What voltage is the Mersen A4J400 rated for?
The fuse is rated for operation at up to 600 V AC and 300 V DC.
Is the A4J400 a time-delay fuse?
No. The A4J400 is a fast-acting Class J current-limiting fuse designed to interrupt overcurrents and short-circuit faults rapidly.
What fuse holder is required for the A4J400?
The A4J400 should be installed in a compatible Class J fuse holder rated for a 400 A fuse and the applicable system voltage.
Trusted Industrial Circuit Protection
Mersen Amp-Trap Class J fuses are widely specified by electrical engineers, panel builders and maintenance professionals for dependable current limitation and high-performance protection in demanding industrial power systems.
