A4BY650 - 650Amp Fuse

A4BY650 - 650Amp Fuse

Protect your electrical systems with confidence using the Mersen A4BY650 Amp-Trap® Class L Time-Delay Fuse. Rated at 650 amps, this fuse is perfect for service entrance equipment, feeder circuits, and circuit breakers. Its smart time-delay design lets harmless surges—like motor startups or short voltage spikes—pass without tripping, but acts instantly when a real overcurrent occurs. That means your equipment stays safe, downtime is minimized, and your operations keep running smoothly.

Installation is quick and easy thanks to silver-plated copper blade terminals and a bolt-mounted design. Plus, clear markings make identification and replacement straightforward, saving time and reducing maintenance headaches.

Key Features and Benefits

• Time-delay design prevents unnecessary trips from harmless surges
• 650A rating for medium to high-current circuits
• Rated for 600VAC / 300VDC applications
• 200kA AC interrupting capacity for fast fault protection
• Continuous-duty operation at full amp rating
• Easy-to-read markings simplify maintenance
• Bolt-mounted installation ensures secure and stable fit

Technical Specifications

• Catalog Number: A4BY650
• Series: A4BY – Class L – Time-Delay
• Fuse Class: Class L
• Ampere Rating: 650A
• 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
• Meets industry standards for industrial and commercial circuit protection

Where It Works Best

• The A4BY650 is perfect for applications where reliable surge tolerance and fast fault response are crucial:
• Service entrance panels
• Feeder circuits and distribution systems
• Industrial machinery protection
• Commercial power systems
• Critical circuit breakers in essential infrastructure
• With its time-delay performance, secure blade terminals, and strong interrupting capacity, the Mersen A4BY650 keeps your electrical systems safe, efficient, and running without a hitch—ideal for both commercial and industrial setups.