Why Choose the Mersen A4BQ500 Class L Time-Delay Fuse?
The Mersen A4BQ500 is a high-performance Class L time-delay fuse designed to protect industrial and commercial electrical systems against damaging overloads and short-circuit currents. As part of the proven Mersen Amp-Trap 2000® A4BQ series, it is engineered for service entrance equipment, switchgear, feeder circuits and other demanding power distribution applications.
The A4BQ500 uses advanced current-limiting technology to reduce the short-circuit current and energy reaching downstream electrical components. Mersen states that Amp-Trap 2000 A4BQ fuses provide enhanced current limitation compared with conventional Class L fuses, helping protect conductors, switchgear and connected equipment during severe fault conditions.
With a rated current of 500 A and voltage ratings of 600 V AC and 500 V DC, the A4BQ500 is suitable for high-capacity electrical distribution systems. Its built-in 4-second time-delay characteristic at 500% of rated current accommodates temporary motor, transformer and equipment inrush currents without nuisance fuse operation.
Key Advantages
- Reliable Class L time-delay fuse for industrial power protection.
- 500 A current rating for high-capacity electrical circuits.
- 600 V AC and 500 V DC voltage ratings.
- Advanced Amp-Trap 2000® current-limiting technology.
- Time-delay performance accommodates temporary equipment inrush currents.
- 200 kA AC interrupting capacity for severe fault protection.
Key Features
- Mersen Amp-Trap 2000® A4BQ series.
- 500 A rated current.
- 600 V AC rated voltage.
- 500 V DC rated voltage.
- Class L time-delay fuse.
- 4-second time delay at 500% of rated current.
- 200 kA AC maximum interrupting capacity.
- Silver-plated copper blade terminals.
- Bolted mounting for secure installation.
- Suitable for 50 / 60 Hz electrical systems.
Reliable Protection for Industrial Power Distribution
The Mersen A4BQ500 protects electrical systems by limiting the amount of fault current and energy that can pass through a circuit during a short circuit. This helps reduce thermal and mechanical stress on switchgear, conductors and connected equipment, supporting improved electrical safety and long-term system reliability.
Its time-delay characteristic makes the fuse suitable for circuits containing motors, transformers and other inductive loads that generate temporary start-up currents. The A4BQ500 tolerates normal inrush conditions while responding effectively to sustained overloads and dangerous short-circuit faults.
Typical Applications
- Service entrance equipment.
- Industrial switchgear and switchboards.
- Electrical feeder circuits.
- Motor control centres.
- Transformer protection systems.
- Main power distribution panels.
- Manufacturing and processing facilities.
