JL3B300 - 300Amp Circuit Breaker

JL3B300 - 300Amp Circuit Breaker

The JL3B300 provides a handful of concrete details to check when replacing a breaker on equipment already in service. It is rated 300 amps, has three poles, and uses a JL3 frame. The breaker measures 9.00 inches wide, 11.00 inches long, and 4.00 inches deep so that you can compare the footprint directly with the existing installation. That 400-amp designation refers to the frame identification; the JL3B300 itself is rated at 300 amps. The JL3B300 is built to last, while keeping the focus where it belongs for replacement work: the right form, fit, ratings, and function.

Key Features and Benefits

• 300A rating with three poles for equipment requiring this specific electrical arrangement.
• JL3 frame provides an important reference point when checking compatibility.
• Measures 9.00" W × 11.00" L × 4.00" D, giving you published dimensions to compare with the breaker being replaced.
• 40°C rated according to the supplied specifications.
• Additional identification of Type ET, 400 Ampere "JL" Frame helps with nameplate and frame matching.
  

Technical Specifications

• Part Number: JL3B300
  
• Product Type: Molded Case Circuit Breaker
  
• Frame Type: JL3
  
• Rated Current: 300A
  
• Number of Poles: 3
  
• AIC Rating at 240VAC: 42 kA
  
• AIC Rating at 480VAC: 30 kA
  
• AIC Rating at 600VAC: 22 kA
  
• Temperature Rating: 40°C
  
• Additional Identification: Type ET, 400 Ampere "JL" Frame
  
• Width: 9.00 in.
  
• Height / Length: 11.00 in.
  
• Depth: 4.00 in.
  
• Overall Dimensions: 9.00 in. W × 11.00 in. L × 4.00 in. D
  
• Approximate Ship Weight: 22.00 lb.
  

Material Compliance and Certifications

The supplied information does not list specific UL, CSA, IEC, RoHS, REACH, or other compliance certifications for the JL3B300. Those certifications should not be assumed. Where a particular approval is required, check the breaker label and applicable equipment documentation before installation.

Where It Works Best

The JL3B300 is intended for compatible existing and legacy equipment that requires a 300A, three-pole molded-case circuit breaker with an JL3 frame and the corresponding physical and electrical characteristics.

For replacement work, compare more than the catalog number. Check the JL3 frame, 300A rating, three-pole arrangement, dimensions, system voltage, and required interrupting capacity against the breaker and equipment already in place. The Type ET, 400 Ampere "JL" Frame identification is another useful detail to verify when confirming form, fit, and functional compatibility.