Why Choose the Mersen A4BQ1200 Class L Fuse?
The Mersen A4BQ1200 is a high-performance Class L time-delay current-limiting fuse designed to provide superior protection for industrial power distribution systems, service entrance equipment and high-current electrical installations. As part of the trusted Mersen Amp-Trap 2000 A4BQ series, it combines outstanding current-limiting performance with a built-in time-delay characteristic to protect critical equipment while accommodating temporary inrush currents.
Rated at 1200 A, 600 V AC and 500 V DC, the A4BQ1200 rapidly interrupts damaging fault currents while reducing peak let-through current and energy. Its 4-second time-delay characteristic at 500% of rated current allows harmless motor starting and transformer energisation currents to pass without nuisance operation.
Designed for demanding industrial applications, the A4BQ1200 is widely used in switchboards, service entrance equipment, feeder circuits and motor control centres. Its rejection-style Class L construction helps prevent incorrect fuse replacement while providing dependable protection in high fault-current environments.
Key Advantages
- Heavy-duty Class L time-delay current-limiting fuse.
- 1200 A current rating for high-capacity power systems.
- 600 V AC and 500 V DC voltage ratings.
- 300 kA AC interrupting capability under UL witnessed testing.
- Built-in 4-second time delay helps eliminate nuisance fuse operation.
- Current-limiting construction reduces damaging fault energy.
Key Features
- Mersen Amp-Trap 2000 A4BQ series.
- 1200 A rated current.
- 600 V AC maximum voltage.
- 500 V DC maximum voltage.
- Class L rejection-style current-limiting fuse.
- Time-delay characteristic for motors and transformers.
- Fibreglass body with high-grade silica filler.
- Blade terminals for compatible Class L fuse holders.
Reliable Protection for High-Power Distribution Systems
The Mersen A4BQ1200 is engineered to provide exceptional protection against overloads and short circuits in high-capacity electrical systems. Its advanced current-limiting design minimises peak fault current and let-through energy, helping protect expensive switchgear, transformers, cables and downstream electrical equipment.
Its built-in time-delay characteristic allows normal inrush currents associated with motors and transformers while maintaining rapid response to sustained overloads and fault conditions. This improves system reliability and supports selective coordination in critical industrial installations.
Typical Applications
- Industrial switchboards.
- Service entrance equipment.
- Main feeder circuits.
- Motor control centres.
- Transformer protection.
- Heavy industrial power distribution systems.
