A4BY1800 - 1800Amp Fuse

A4BY1800 - 1800Amp Fuse

Meet the Mersen A4BY1800 Amp-Trap® Class L Time-Delay Fuse—your go-to solution for keeping high-current electrical systems safe without compromising performance. Rated for 1800 amps, this fuse is built to handle heavy-duty service entrance equipment, feeder circuits, and circuit breakers. Its smart time-delay design lets it ride through harmless surges, like motor startups or temporary spikes, so you don’t get unnecessary trips—but it acts fast when a real fault occurs, protecting your equipment and minimizing downtime.

If you want protection that’s precise, dependable, and built for real-world performance, the A4BY1800 has you covered.

Key Features and Benefits

• Time-delay design passes harmless surges without tripping
• 1800A rating for heavy-duty service entrance and feeder circuits
• Rated for 600VAC / 300VDC applications
• High 200kA AC interrupting capacity for fault clearing
• Silver-plated copper blade terminals for reliable connections
• Clear markings simplify identification and servicing
• Bolt-mounted installation for secure connections

Technical Specifications

• Catalog Number: A4BY1800
• Series: A4BY – Class L – Time-Delay
• Fuse Class: Class L
• Ampere Rating: 1800A
• 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)
• Diameter: 88.9 mm
• Length: 273 mm
• Product Weight: 3.8374 kg

Material Compliance and Certifications

• RoHS Compliant
• Meets UL/CSA standards for low-voltage fuses

Where It Works Best

• The A4BY1800 shines in applications where high-current protection and surge tolerance are essential:
• Service entrance panels
• Feeder circuits and distribution systems
• Industrial machinery protection
• Commercial power distribution
• Circuit breakers in critical infrastructure
• Fast, reliable, and built to last, the Mersen A4BY1800 is a fuse that keeps your electrical systems running safely and smoothly—exactly what you need in demanding industrial or commercial environments.