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MERSEN FUSE L TD FUSE 600V 250A A4BQ A4BQ250
The A4BQ250 time-delay fuse delivers superior circuit protection for heavy-duty industrial applications, supporting up to 250A at 600VAC or 500VDC. Its advanced dual-blade construction ensures robust performance and reliable interruption of high fault currents, minimising equipment downtime.
£620.14
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.
Technical Specifications
Tick the specs you need, then view products that match.
| Current | 250 A | |
|---|---|---|
| Voltage | 600 V | |
| Fuse Type | UL class | |
| Fuse Class | Time delay | |
| Item number | A4BQ250 | |
| Description | Fuse A4BQ - Class L - Time-Delay 600VAC 500VDC 250A Blade Amp-Trap 2000® | |
| EAN/UPC Code | 782001931100 | |
| Rated voltage AC UL | 600 V | |
| Rated voltage DC UL | 500 V | |
| Frequency (Hz) | 50/60 Hz | |
| Ampere Rating | 250 A | |
| AC or DC | AC/DC | |
| Fuse Class | Class L | |
| Speed/Characteristic | Time Delay | |
| Mounting | Bolted | |
| AC Max I.R./Breaking Capacity | I1: 200 kA | |
| Connection/Terminal Material | Silver-Plated Copper | |
| Connection/Terminal Type | Blade | |
| Product Diameter | 50.8 mm | |
| Product Length | 219.2 mm | |
| Sell Pack Quantity | 1 EA | |
| Sell Pack Weight | 1.1612 kg | |
| Sell Pack Width | 53.8 mm | |
| Sell Pack Length | 53.8 mm | |
| Sell Pack Height | 223.8 mm | |
| Product group | Low Voltage UL/CSA Fuses | |
| Body/Insulating Material | GMG | |
| Product Weight | 1.1068 kg | |
| HS Code | 85361090 | |
| Country of Manufacture | Mexico |
Frequently Asked Questions
What is the Mersen A4BQ250 used for?
The Mersen A4BQ250 protects industrial power distribution systems, service entrance equipment, transformers, motors and feeder circuits against overloads and short circuits.
What is the current rating of the A4BQ250?
The Mersen A4BQ250 has a rated current of 250 A.
What voltage is the A4BQ250 rated for?
The fuse is rated for applications operating at up to 600 V AC and 500 V DC.
Why does the A4BQ250 include a time-delay feature?
The built-in 4-second time delay allows temporary motor and transformer inrush currents to pass without nuisance fuse operation while maintaining rapid protection against sustained overloads and fault currents.
Where is the A4BQ250 typically installed?
The A4BQ250 is commonly installed in service entrance equipment, industrial switchboards, feeder circuits and compatible Class L fuse holders.
Trusted Industrial Circuit Protection
Mersen Amp-Trap 2000 Class L fuses are trusted by electrical engineers, panel builders and industrial facilities worldwide for dependable protection of critical power distribution systems.
