Why Choose the Mersen A4BQ1900 Class L Fuse?
The Mersen A4BQ1900 is a premium Class L time-delay current-limiting fuse engineered to protect industrial power distribution systems, service entrance equipment and heavy-duty electrical installations against overloads and short circuits. As part of the proven Mersen Amp-Trap 2000 A4BQ series, it provides industry-leading current limitation combined with dependable time-delay performance for demanding industrial applications.
Rated at 1900 A, 600 V AC and 500 V DC, the A4BQ1900 is designed for high-power electrical systems with significant available fault currents. Its advanced current-limiting design reduces peak let-through current and fault energy, helping to protect switchgear, transformers, busbars, conductors and downstream equipment from severe thermal and mechanical damage.
The fuse features a built-in 4-second time-delay characteristic at 500% of rated current, allowing temporary motor starting, transformer energisation and other equipment inrush currents to pass without nuisance operation while providing rapid interruption of sustained overloads and short-circuit faults.
Key Advantages
- Heavy-duty Class L time-delay current-limiting fuse.
- 1900 A current rating for high-capacity industrial systems.
- 600 V AC and 500 V DC voltage ratings.
- 200 kA AC interrupting rating (300 kA self-certified, UL witnessed).
- Built-in 4-second time delay prevents nuisance operation during equipment start-up.
- Advanced current limitation reduces damaging short-circuit energy.
Key Features
- Mersen Amp-Trap 2000 A4BQ series.
- 1900 A rated current.
- 600 V AC maximum voltage rating.
- 500 V DC maximum voltage rating.
- Class L rejection-style fuse construction.
- 4-second time-delay characteristic.
- Current-limiting design with pure silver fuse links.
- Silver-plated copper blade terminals with bolted mounting.
Reliable Protection for High-Power Distribution Systems
The Mersen A4BQ1900 interrupts excessive fault currents before they reach damaging levels. By limiting peak current and let-through energy, it helps protect expensive electrical infrastructure while reducing stress on cables, switchboards, transformers and other distribution equipment.
Its integrated time-delay characteristic accommodates harmless inrush currents from motors and transformers while maintaining fast protection against sustained overloads and fault conditions. This makes the A4BQ1900 ideal for applications requiring dependable protection and selective coordination.
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 facilities.
- High-current AC and DC power distribution systems.
