Why Choose the Mersen A4BQ250 Class L Fuse?
The Mersen A4BQ250 is a premium Class L time-delay current-limiting fuse designed to protect industrial power distribution systems, service entrance equipment and heavy-duty electrical installations against overloads and short circuits. Part of the renowned Mersen Amp-Trap 2000 A4BQ series, it delivers exceptional current limitation while accommodating normal inrush currents from motors and transformers without nuisance operation.
Rated at 250 A, 600 V AC and 500 V DC, the A4BQ250 rapidly interrupts damaging fault currents while minimising peak let-through current and energy. Its advanced current-limiting design helps protect switchgear, transformers, busbars, conductors and downstream equipment from costly thermal and mechanical damage.
The fuse incorporates 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. Its rejection-style Class L construction helps prevent incorrect fuse replacement, improving installation safety and system reliability.
Key Advantages
- Industrial Class L time-delay current-limiting fuse.
- 250 A current rating for industrial power distribution.
- 600 V AC and 500 V DC voltage ratings.
- 300 kA self-certified interrupting rating (UL witnessed testing).
- Built-in 4-second time delay reduces nuisance operation during equipment start-up.
- Advanced current-limiting technology minimises damaging fault energy.
Key Features
- Mersen Amp-Trap 2000 A4BQ series.
- 250 A rated current.
- 600 V AC maximum voltage rating.
- 500 V DC maximum voltage rating.
- Class L rejection-style fuse construction.
- Time-delay characteristic for motors and transformers.
- Pure silver fuse links for outstanding current limitation.
- Blade terminals for compatible Class L fuse holders.
Reliable Protection for Industrial Power Distribution
The Mersen A4BQ250 provides outstanding protection against overloads and short circuits by limiting peak fault current and let-through energy before damage can occur. This helps extend the service life of switchgear, transformers, cables and other critical electrical infrastructure while improving system reliability.
Its integrated time-delay characteristic allows temporary motor and transformer inrush currents without nuisance fuse operation, making the A4BQ250 ideal for industrial installations where dependable protection and selective coordination are essential.
Typical Applications
- Service entrance equipment.
- Industrial switchboards.
- Main feeder circuits.
- Motor control centres.
- Transformer protection.
- Industrial power distribution systems.
- Circuit breaker back-up protection.
- UPS DC links and battery disconnect applications.
