A4BY800 - 800Amp Fuse

A4BY800 - 800Amp Fuse

Ensure your electrical systems are protected with the Mersen A4BY800 Amp-Trap® Class L Time-Delay Fuse. Rated at 800 amps, this fuse is designed for service entrance equipment, feeder circuits, and circuit breakers. Its smart time-delay design allows harmless surges, like motor starts or temporary voltage spikes, to pass without tripping, while reacting instantly to actual overcurrent events. This keeps your equipment safe and helps minimize downtime.

Installation is straightforward with silver-plated copper blade terminals and a bolt-mounted design. The durable glass melamine (GMG) body maintains stability under continuous use, while the 200kA AC interrupting rating ensures your systems are protected even under demanding industrial and commercial conditions. Clear markings make identification and replacement quick, saving time and reducing maintenance effort.

Key Features and Benefits

• Time-delay design prevents trips from harmless surges
• 800A rating for medium to high-current circuits
• Rated for 600VAC / 300VDC applications
• 200kA AC interrupting capacity for fast fault protection
• Silver-plated copper blade terminals for secure connections
• Durable GMG (glass melamine) body for long-lasting stability
• Continuous-duty operation at full amp rating
• Clear markings simplify identification and replacement
• Bolt-mounted installation ensures secure fit

Technical Specifications

• Catalog Number: A4BY800
• Series: A4BY – Class L – Time-Delay
• Fuse Class: Class L
• Ampere Rating: 800A
• Voltage Rating: 600VAC / 300VDC
• Frequency: 50/60 Hz
• Speed/Characteristic: Time-Delay
• Mounting: Bolted
• Connection Type: Blade
• Connection Material: Silver-Plated Copper
• AC Max Interrupting Rating: 200kA
• Body Material: GMG (Glass Melamine)
• Product Diameter: 50.8 mm
• Product Length: 219.2 mm
• Product Weight: 1.6511 kg

Material Compliance and Certifications

• RoHS Compliant
• UL/CSA approved for low-voltage applications

Where It Works Best

• Service entrance panels
• Feeder circuits and distribution systems
• Industrial machinery protection
• Commercial power systems
• Circuit breakers in critical infrastructure
• With its combination of time-delay performance, secure blade terminals, and strong interrupting capacity, the Mersen A4BY800 keeps your electrical systems safe, efficient, and running smoothly in demanding commercial and industrial setups.