TJK426300 **Older Style** - 300Amp Circuit Breaker

TJK426300 **Older Style** - 300 Amp Circuit Breaker

The TJK426300 molded case circuit breaker is designed for your dependable protection in commercial and industrial electrical distribution systems where maintaining compatibility with existing equipment matters. Built as part of the Q-Line family, this 2-pole, 300 amp breaker features a thermal magnetic trip unit with internal common trip to help you protect circuits from overloads and short circuits. Its bolt-on mounting design supports a secure installation in compatible panelboards and switchgear applications, while the included load-side lugs help simplify field connections.

This older style black face configuration is commonly used in legacy electrical systems requiring specific form, fit, and function characteristics. The breaker includes a non-interchangeable trip unit and is HACR rated, making it suitable for heating, air conditioning, and refrigeration equipment applications where properly rated protection is required. With interrupting capacities rated up to 42k A.I.C. at 240VAC, the TJK426300 is built to last and intended for demanding power distribution environments that require consistent circuit protection and compatibility with existing infrastructure.

Key Features and Benefits

• 300 Amp, 2-Pole Configuration: For commercial and industrial power distribution applications.
• Older Style Black Face Design: For compatibility with select legacy systems and installations.
• Thermal Magnetic Trip Unit: Helps provide protection against overloads and short circuits.
• Internal Common Trip Mechanism: Disconnects both poles simultaneously during fault conditions.
• Bolt-On Mounting Style: Supports a stable and secure installation.
• Q-Line Series Breaker: Designed for use in compatible panelboards and switchgear assemblies.
• HACR Rated: For heating, air conditioning, and refrigeration equipment applications.
• Includes Load-Side Lugs: To assist with installation and conductor termination.
• Non-Interchangeable Trip Unit: Maintains the original breaker configuration and calibration.
• Built for Long-Term Use: In demanding electrical environments.
  

Technical Specifications

• Part Number: TJK426300
  
• Type: TJK4
  
• Product Style: Older Style Black Face
  
• Circuit Breaker Type: Molded Case Circuit Breaker
  
• Poles: 2
  
• Amperage: 300A
  
• Voltage / A.I.C. Rating:
  • 22k @ 600VAC
  • 30k @ 480VAC
  • 42k @ 240VAC
• Trip Unit: Thermal Magnetic
  
• Trip Configuration: Internal Common Trip
  
• Mounting Style: Bolt-On
  
• Series: Q-Line
  
• HACR Rated: Yes
  
• Lugs: Includes Load-Side Lugs
  
• Height: 10.13 in.
  
• Width: 8.25 in.
  
• Depth: 3.81 in.
  

Material Compliance and Certifications

• HACR Rated: For approved HVAC and refrigeration-related applications.
• Manufactured for Use in Accordance with Applicable Standards: Manufactured for use in accordance with applicable molded case circuit breaker standards and electrical distribution requirements.
• Designed for Compatibility: Designed for compatibility within properly rated electrical systems and assemblies.
  

Where It Works Best

• The TJK426300 is well suited for commercial buildings, industrial facilities, manufacturing environments, and large electrical distribution systems that require a 300 amp bolt-on molded case circuit breaker. It is commonly used in:
• Electrical distribution panels
• Industrial control systems
• HVAC equipment disconnect and protection applications
• Commercial power distribution equipment
• Legacy Q-Line panelboard systems requiring older style black face breakers
• Facility maintenance and replacement projects where matching existing equipment specifications is important