Why Choose the Mersen AJT400 Class J Time-Delay Fuse?
The Mersen AJT400 is a premium Class J time-delay fuse engineered to provide dependable overcurrent protection for high-current industrial electrical systems. As part of the trusted Mersen Amp-Trap 2000® AJT series, it combines exceptional current-limiting performance with time-delay characteristics, making it ideal for protecting main circuits, feeders, motor branch circuits and industrial machinery exposed to demanding operating conditions.
Built using advanced fuse technology, the AJT400 is designed to tolerate temporary motor starting and transformer energisation currents while rapidly clearing sustained overloads and short circuits. Its compact Class J construction requires approximately half the mounting space of comparable Class RK fuses, allowing more efficient panel layouts while maintaining high levels of electrical protection.
With a rated current of 400 A and a 600 V AC / 400 V DC rating, the AJT400 is ideally suited to industrial power distribution systems, OEM machinery, switchboards and motor control applications. The blade terminal design provides secure installation into compatible Class J fuse holders and fused disconnect switches.
Key Advantages
- High-capacity Class J time-delay fuse for industrial circuit protection.
- 400 A current rating for demanding power distribution applications.
- 600 V AC and 400 V DC voltage rating.
- Time-delay characteristics accommodate motor and transformer inrush currents.
- Superior current-limiting performance helps minimise equipment damage.
- Compact Class J design saves valuable control-panel space.
Key Features
- Mersen Amp-Trap 2000® AJT series.
- 400 A rated current.
- 600 V AC / 400 V DC rated voltage.
- Class J time-delay fuse construction.
- Blade terminal connection.
- 200 kA AC interrupting rating.
- Available with SmartSpot® visual open-fuse indication.
- Supports IEC Type 2 No Damage protection.
Reliable Protection for High-Current Industrial Systems
The Mersen AJT400 protects electrical equipment by interrupting dangerous overload and short-circuit currents before they can damage motors, transformers, switchgear and power distribution equipment. Its time-delay operation allows temporary inrush currents during normal equipment start-up while maintaining dependable protection against sustained faults.
Its high interrupting capacity and advanced current-limiting characteristics help reduce thermal and mechanical stress on downstream equipment, making it an excellent choice for industrial facilities where reliability, uptime and equipment protection are essential.
Typical Applications
- Main and feeder circuit protection.
- High-current motor branch circuits.
- Industrial transformer protection.
- Switchboards and power distribution panels.
- OEM machinery and automation systems.
- Industrial fused disconnect switches.
