Why Choose the Mersen A4BQ650 Class L Time-Delay Fuse?
The Mersen A4BQ650 is a premium Class L time-delay fuse designed to provide superior overcurrent and short-circuit protection for industrial and commercial power distribution systems. As part of the trusted Amp-Trap 2000® A4BQ series, it offers industry-leading current limitation and dependable protection for service entrance equipment, switchgear, feeder circuits and other critical electrical installations.
Featuring advanced Amp-Trap 2000® technology, the A4BQ650 delivers up to 20% greater current limitation than conventional Class L fuses, reducing damaging fault energy reaching downstream equipment. Its integrated 4-second time-delay characteristic at 500% of rated current accommodates temporary inrush currents from motors, transformers and other inductive loads without nuisance operation.
With a 650 A current rating and voltage ratings of 600 V AC and 500 V DC, the A4BQ650 is engineered for demanding electrical distribution systems requiring exceptional fault protection, high interrupting capacity and long-term reliability.
Key Advantages
- High-performance Class L time-delay fuse for industrial power distribution.
- 650 A current rating for high-capacity electrical systems.
- 600 V AC / 500 V DC voltage ratings.
- Advanced Amp-Trap 2000® current-limiting technology.
- 4-second time-delay minimises nuisance operation during motor and transformer start-up.
- 300 kA AC interrupting rating with excellent current limitation.
Key Features
- Mersen Amp-Trap 2000® A4BQ series.
- 650 A ampere rating.
- 600 V AC / 500 V DC rated voltage.
- Class L current-limiting time-delay fuse.
- 4-second minimum time delay at 500% rated current.
- 300 kA AC interrupting rating (UL witnessed).
- 100 kA DC interrupting rating.
- Blade terminals with bolted mounting.
- Fibreglass body with high-grade silica filler.
- Suitable for 50 / 60 Hz electrical systems.
Reliable Protection for Industrial Power Systems
The Mersen A4BQ650 is designed to minimise damage caused by overloads and severe short-circuit faults. Its advanced current-limiting construction significantly reduces peak let-through current and energy, helping protect switchgear, conductors and downstream equipment from thermal and mechanical stress.
Its time-delay operating characteristic allows temporary motor and transformer inrush currents to pass without nuisance opening while maintaining dependable protection against sustained overloads and fault currents. This makes the A4BQ650 ideal for demanding industrial installations where uptime and equipment protection are critical.
Typical Applications
- Service entrance equipment.
- Industrial switchgear and switchboards.
- Main electrical distribution systems.
- Feeder circuit protection.
- Motor control centres.
- Transformer protection.
- Heavy industrial and commercial facilities.
