AJT400 - 400 Amp Fuse

AJT400 - 400 Amp Fuse

The AJT400 Class J Time-Delay Fuse is built for your electrical systems that handle large motors, transformers, HVAC equipment, and other heavy-duty loads. In many commercial and industrial applications, equipment pulls extra current for a short time during startup. The AJT400 is designed to handle those temporary surges without opening unnecessarily, while still providing dependable protection when overloads or short circuits happen.

Its compact Class J design helps you save space inside switchboards, control panels, and electrical enclosures, making it a practical option when panel space is limited. The fuse also provides current-limiting protection, helping reduce the amount of fault current that passes through the system during a short circuit. That can help you limit damage to connected equipment, wiring, and electrical components.

The built-in SmartSpot® visual indicator helps make maintenance easier too. When the fuse opens, technicians can quickly identify the affected fuse without spending extra time troubleshooting the system.

The AJT400 is commonly used in commercial and industrial power distribution systems where reliable overcurrent protection is needed every day. Its combination of time-delay performance, compact sizing, and high interrupting capacity makes it a dependable choice for demanding electrical applications.

Key Features and Benefits

• Time-delay design helps reduce nuisance openings during startup currents: Helps allow normal equipment startup surges without unnecessary fuse operation.
• Current-limiting protection helps reduce damage during fault conditions: Helps reduce fault energy passing through the system during short circuits.
• Compact Class J size helps save panel space: Useful for tighter switchboards, control panels, and electrical enclosures.
• SmartSpot® visual indicator helps identify opened fuses quickly: Supports faster troubleshooting and maintenance.
• High interrupting capacity for demanding electrical systems: Built for commercial and industrial applications with high available fault current.
• Suitable for AC and DC applications: Supports a range of power distribution systems.
• Blade-style terminals support secure installation: Helps maintain dependable electrical connections.
• Commonly used in commercial and industrial electrical systems: Designed for reliable overcurrent protection in demanding environments.
  

Technical Specifications

• Catalog Number: AJT400
  
• Series: AJT – Class J – Time-Delay
  
• Fuse Type: Amp-Trap 2000®
  
• Ampere Rating: 400 Amps
  
• Voltage Rating (AC): 600 VAC
  
• Voltage Rating (DC): 500 VDC
  
• Frequency: 50/60 Hz
  
• Fuse Class: Class J
  
• Characteristic: Time Delay
  
• Interrupting Rating: 200 kA
  
• Mounting Type: Clip or Bolted
  
• Terminal Type: Blade
  
• Terminal Material: Brass
  
• Indication System: SmartSpot® Visual Indicator
  
• Body Material: GMG
  
• Product Diameter: 54 mm
  
• Product Length: 181.1 mm
  
• Product Weight: 0.8119 kg
  

Material Compliance and Certifications

• Industry Standards: The AJT400 fuse is designed for low-voltage UL and CSA applications and supports IEC Type 2 “No Damage” protection requirements when properly coordinated within electrical systems.
  

Where It Works Best

• The AJT400 is commonly installed in motor control centers, HVAC systems, industrial machinery, transformers, switchboards, feeder circuits, branch circuits, and commercial power distribution systems where temporary startup surges are expected during normal operation.