A4BY900 - 900Amp Fuse

A4BY900 - 900Amp Fuse

Keep your electrical systems protected and running smoothly with the Mersen A4BY900 Amp-Trap® Class L Time-Delay Fuse. Designed for medium to high-current applications, this 900A fuse is perfect for service entrance equipment, feeder circuits, and circuit breakers. Its clever time-delay design allows harmless surges—like motor starts or temporary voltage spikes—to pass without tripping, while reacting instantly to real overcurrent events to protect your equipment and minimize downtime.

Installing the A4BY900 is straightforward thanks to silver-plated copper blade terminals and a bolt-mounted design. The durable glass melamine (GMG) body stands up to continuous heavy use, and its 200kA AC interrupting rating ensures reliable protection under demanding industrial and commercial conditions.

Key Features and Benefits

• Time-delay design lets harmless surges pass without unnecessary trips
• 900A rating for medium to high-current circuits
• Rated for 600VAC / 300VDC applications
• 200kA AC interrupting capacity for fast fault response
• 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: A4BY900
• Series: A4BY – Class L – Time-Delay
• Fuse Class: Class L
• Ampere Rating: 900A
• 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: 63.5 mm
• Product Length: 273 mm
• Product Weight: 1.9414 kg

Material Compliance and Certifications

• RoHS Compliant
• UL/CSA approved for low-voltage applications
• Meets industry standards for industrial and commercial electrical protection

Where It Works Best

• Service entrance panels
• Feeder circuits and distribution systems
• Industrial machinery protection
• Commercial power systems
• Critical circuit breakers in essential infrastructure
• With its smart time-delay design, secure blade terminals, and high interrupting capacity, the Mersen A4BY900 keeps your electrical systems safe, efficient, and running without interruptions—perfect for both commercial and industrial setups.