TJK426300WL **Older Style** - 300Amp Circuit Breaker

TJK426300WL **Older Style** - 300 Amp Circuit Breaker

When you’re maintaining an existing electrical system, finding the right breaker is about more than just amperage — it’s about compatibility, fit, and dependable protection. The TJK426300WL molded case circuit breaker is designed as a practical replacement for legacy commercial and industrial power distribution equipment that uses the older black-face configuration. Built as part of the trusted Q-Line Type TJK4 series, this 300-amp, 2-pole breaker combines durable construction with the everyday functionality that electricians and maintenance teams rely on in the field.

Equipped with a non-interchangeable thermal magnetic trip unit, the TJK426300WL helps protect electrical systems against overloads and short circuits while maintaining consistent operation in demanding environments. Its internal common trip mechanism ensures both poles trip together when needed, helping support safer system protection. The included line and load-side lugs, and the cable-in/cable-out lug-lug design, make installation straightforward for panelboards, switchboards, HVAC systems, and industrial distribution setups operating up to 600VAC.

Because many facilities continue operating long-established infrastructure, matching the original form and fit of existing equipment can save valuable time during maintenance and replacement projects. The TJK426300WL is built with that in mind — offering the ratings, dimensions, and connection style needed for seamless integration into compatible systems. Built to last and designed for real-world applications, this breaker remains a dependable choice for keeping essential electrical systems operating smoothly.

Key Features and Benefits

• 300 Amp Continuous Current Rating: Designed for commercial and industrial applications requiring dependable high-capacity circuit protection.
• 2-Pole Molded Case Circuit Breaker: Provides reliable circuit protection for compatible electrical systems.
• Older Style Black Face Configuration: Supports compatibility with existing equipment and legacy installations.
• Thermal Magnetic Trip Unit: Helps protect against overloads and short circuits while maintaining dependable operation.
• Internal Common Trip Design: Allows coordinated pole operation for safer system protection.
• Q-Line Type TJK4 Construction: Built for use in compatible electrical distribution systems.
• Cable-in/Cable-out (Lug-Lug) Connection Style: Supports direct wiring applications for installation flexibility.
• Includes Line and Load-Side Lugs: Provides installation convenience for maintenance and replacement projects.
• HACR Rated: Suitable for heating, air conditioning, and refrigeration equipment applications.
• Built for Long-Term Use: Designed for demanding electrical environments and ongoing system reliability.
  

Technical Specifications

• Part Number: TJK426300WL
  
• Type: TJK4
  
• Circuit Breaker Style: Molded Case Circuit Breaker
  
• Face Style: Older Style Black Face
  
• Poles: 2
  
• Amperes: 300A
  
• Trip Unit: Non-Interchangeable Thermal Magnetic
  
• Trip Function: Internal Common Trip
  
• Connection Type: Cable-in/Cable-out (Lug-Lug)
  
• Included Accessories: Line and Load-Side Lugs
  
• HACR Rated: Yes
  
• A.I.C. Rating @ 240VAC: 42k
  
• A.I.C. Rating @ 480VAC: 30k
  
• A.I.C. Rating @ 600VAC: 22k
  
• Dimensions:
  • Height: 10.13 in.
  • Width: 8.25 in.
  • Depth: 3.81 in.

Material Compliance and Certifications

• HACR Rated: The TJK426300WL circuit breaker is designed for use in commercial and industrial electrical distribution systems that require dependable overcurrent protection and compatibility with existing equipment configurations. This breaker is HACR-rated, making it suitable for use with heating, ventilation, air conditioning, and refrigeration equipment, where applicable.
  

Where It Works Best

• The TJK426300WL is commonly used in commercial buildings, industrial facilities, electrical distribution panels, switchboards and panelboards, HVAC and refrigeration systems, manufacturing environments, retrofit and maintenance projects, and legacy electrical systems requiring compatible replacement components. Its older-style black-face design and lug-lug configuration make it especially useful for applications where maintaining original equipment compatibility is important, reducing installation changes and minimizing downtime.