Why Choose the Mersen AJT500 Class J Time-Delay Fuse?
The Mersen AJT500 is a high-capacity Class J time-delay fuse engineered to provide dependable overcurrent protection for demanding industrial electrical systems. As part of the established Mersen Amp-Trap 2000® AJT series, it combines time-delay operation with advanced current-limiting performance, making it suitable for mains, feeders, motor branch circuits, transformers and heavy industrial machinery.
The AJT500 is designed to tolerate normal temporary inrush currents produced during motor starting and transformer energisation while responding effectively to sustained overloads and short circuits. This dual-element performance helps prevent unnecessary fuse operation while limiting the fault current and energy passed to downstream equipment.
With a rated current of 500 A and a voltage rating of 600 V AC / 400 V DC, the AJT500 is suitable for high-current industrial power distribution and machinery protection. Its compact Class J construction and blade terminals enable secure installation in compatible fuse clips, fuse holders and fused disconnect switches.
Key Advantages
- High-capacity Class J time-delay fuse for industrial circuit protection.
- 500 A current rating for demanding power distribution applications.
- 600 V AC / 400 V DC voltage rating.
- Time-delay operation accommodates normal motor and transformer inrush currents.
- Current-limiting performance helps reduce thermal and mechanical fault damage.
- Compact Class J footprint supports space-efficient switchboard and panel designs.
Key Features
- Mersen Amp-Trap 2000® AJT series.
- 500 A rated current.
- 600 V AC / 400 V DC rated voltage.
- Class J dual-element time-delay construction.
- Blade-terminal configuration.
- 200 kA AC interrupting rating.
- Advanced current-limiting protection.
- Designed to accommodate temporary equipment start-up currents.
- Suitable for compatible Class J fuse holders and fused disconnect switches.
Reliable Protection for High-Current Industrial Systems
The Mersen AJT500 helps protect motors, transformers, conductors, switchgear and distribution equipment by interrupting dangerous overcurrents before excessive fault energy can cause serious damage. Its time-delay response permits normal temporary starting currents without compromising protection against sustained overloads and short-circuit conditions.
During a high-level fault, the fuse's current-limiting characteristics restrict the peak current and let-through energy experienced by downstream components. This helps reduce electrical, thermal and mechanical stress while supporting improved equipment reliability and system availability.
Typical Applications
- Main and feeder circuit protection.
- High-current motor branch circuits.
- Industrial transformer protection.
- Motor control centres.
- Switchboards and distribution panels.
- OEM machinery and automation systems.
- Industrial fused disconnect switches.
- Commercial and industrial power distribution systems.
