THJK436300WL - 300Amp Circuit Breaker

THJK436300WL - 300 Amp Circuit Breaker

The THJK436300WL is a 3-pole, 300-amp molded case circuit breaker designed for use in your commercial and industrial electrical distribution systems where dependable circuit protection is required. As part of the THJK4 series, this breaker features a thermal magnetic trip unit with internal common trip functionality, helping to protect your electrical equipment and conductors from overloads and short circuits. Its cable-in/cable-out (lug-lug) configuration includes both line-side and load-side lugs, making installation and replacement straightforward in compatible systems.

Built for demanding electrical environments, the THJK436300WL is a Q-Line circuit breaker that combines a compact footprint with substantial interrupting capacity. The non-interchangeable trip unit provides consistent protection characteristics, while the HACR rating makes it suitable for applications involving heating, air conditioning, and refrigeration equipment. Designed with durability in mind, this breaker is built to provide long service life when properly installed and maintained.

Key Features and Benefits

• 300-amp current rating: For high-capacity power distribution applications.
• 3-pole configuration: For three-phase electrical systems.
• THJK4 series design: Molded case circuit breaker design.
• Thermal magnetic trip unit: Provides protection against overloads and short circuits.
• Internal common trip mechanism: Helps disconnect all poles simultaneously during fault conditions.
• Cable-in/cable-out (lug-lug) construction: For convenient field installation.
• Line and load-side lugs included: Includes both line-side and load-side lugs.
• HACR rated: For compatible heating, air conditioning, and refrigeration applications.
• Q-Line design: For use in compatible electrical distribution equipment.
• Compact molded case construction: Helps conserve panel space.
  

Technical Specifications

• Part Number: THJK436300WL
  
• Series: THJK4
  
• Type: Molded Case Circuit Breaker
  
• Poles: 3
  
• Amperage Rating: 300A
  
• Trip Unit: Thermal Magnetic
  
• Trip Type: Internal Common Trip
  
• Configuration: Cable-In/Cable-Out (Lug-Lug)
  
• Included Connections: Line and Load-Side Lugs
  
• A.I.C. Rating: 25kA @ 600VAC
  
• A.I.C. Rating: 35kA @ 480VAC
  
• A.I.C. Rating: 65kA @ 240VAC
  
• Dimensions:
  • Height: 10.13 in.
  • Width: 8.25 in.
  • Depth: 3.81 in.
• HACR Rated: Yes
  

Material Compliance and Certifications

• HACR Rated: HACR Rated.
• Commercial and Industrial Use: Manufactured for use in applicable commercial and industrial electrical systems.
• Interrupting Capacity Compliance: Designed to meet the requirements associated with its listed interrupting capacities and voltage ratings.
• Installation Requirements: Intended for installation and use in accordance with applicable electrical codes, standards, and manufacturer specifications.
  

Where It Works Best

• The THJK436300WL is well-suited for commercial buildings, industrial facilities, manufacturing operations, distribution equipment, switchboards, panelboards, and HVAC-related electrical systems that require a 300-amp, 3-pole molded case circuit breaker. It is commonly used as a replacement breaker in compatible electrical distribution systems where matching form, fit, and function are important for maintaining existing equipment configurations. Its combination of high interrupting ratings, thermal magnetic protection, and lug-lug connectivity makes it a practical choice for protecting feeders, large branch circuits, and critical power distribution infrastructure.