Why Choose the Mersen A4BQ1800 Class L Fuse?
The Mersen A4BQ1800 is a high-capacity Class L time-delay current-limiting fuse engineered to protect industrial power distribution systems, service entrance equipment and heavy-duty electrical installations against damaging overloads and short circuits. Part of the proven Mersen Amp-Trap 2000 A4BQ series, it delivers effective current limitation while accommodating harmless temporary inrush currents.
Rated at 1800 A, 600 V AC and 500 V DC, the A4BQ1800 is suitable for high-power systems with substantial load currents and available fault levels. Its current-limiting construction reduces short-circuit let-through current, helping protect switchgear, busbars, cables, transformers and other downstream components from severe thermal and mechanical stress.
The fuse features a built-in four-second time delay at 500% of its rated current. This characteristic allows temporary currents associated with motor starting, transformer energisation and other inductive loads to pass without nuisance operation while maintaining dependable protection against sustained overloads and short-circuit faults.
Key Advantages
- Heavy-duty Class L time-delay current-limiting fuse.
- 1800 A current rating for high-capacity power systems.
- 600 V AC and 500 V DC voltage ratings.
- 200 kA AC interrupting rating for high fault-current environments.
- Four-second time delay helps prevent nuisance operation during equipment start-up.
- Advanced current limitation helps reduce damaging short-circuit energy.
Key Features
- Mersen Amp-Trap 2000 A4BQ series.
- 1800 A rated current.
- 600 V AC maximum voltage rating.
- 500 V DC maximum voltage rating.
- Class L rejection-style fuse construction.
- Four-second time delay at 500% rated current.
- Silver-plated copper blade terminals.
- Bolted mounting for secure industrial installation.
Reliable Protection for High-Power Distribution Systems
The Mersen A4BQ1800 limits excessive fault current before it can reach its maximum prospective value. By reducing short-circuit let-through current and energy, the fuse helps minimise damage to conductors, switchboards, transformers and other critical electrical distribution components.
When correctly coordinated, the A4BQ1800 provides a high level of protection for service entrance equipment and downstream circuits. Its time-delay operation allows normal equipment inrush currents to pass while responding reliably to sustained overloads and dangerous short-circuit conditions.
Typical Applications
- Industrial switchboards and distribution panels.
- Service entrance equipment.
- Main distribution and feeder circuits.
- Motor control centres.
- Transformer protection.
- Industrial disconnect switches.
- Heavy manufacturing and process equipment.
- Compatible high-current AC and DC systems.
