LL3B400 - 400Amp Circuit Breaker

LL3B400 - 400Amp Circuit Breaker

See LL3B400 on the breaker you're replacing? That's a much better starting point than simply searching for a 400-amp breaker. The LL3B400 is a 400A, 3-pole molded case circuit breaker, listed as Type LL3 and identified in the supplied specifications as a Type ET, 600 Ampere LL-frame breaker. Its interrupting capacity depends on the application voltage: 42 kA at 240VAC, 30 kA at 480VAC, and 22 kA at 600VAC. The specifications also call out a 40°C rating. For maintenance work on existing equipment, those details help tell you what you're actually dealing with—and whether the breaker you're considering belongs in that application.

Key Features and Benefits

• 400A, 3-pole molded case circuit breaker
• LL3 type configuration
• Identified as a Type ET, 600 Ampere LL-frame breaker
• Specified at 40°C
• Voltage-specific A.I.C. ratings provide clear reference points for matching the breaker to the application
• Useful for form, fit, and functional replacement where existing equipment specifically requires the LL3B400 configuration

Technical Specifications

• Part Number: LL3B400
  
• Product Type: Molded Case Circuit Breaker
  
• Type: LL3
  
• Frame: 600 Ampere LL Frame
  
• Additional Identification: Type ET
  
• Amperage: 400A
  
• Number of Poles: 3
  
• Temperature Rating: 40°C
  
• A.I.C. at 240VAC: 42 kA
  
• A.I.C. at 480VAC: 30 kA
  
• A.I.C. at 600VAC: 22 kA
  
• Width: 9 in.
  
• Height: 11 in.
  
• Depth: 4 in.
  
• Dimensions: 9.00"W x 11.00"H x 4.00"D
  

Material Compliance and Certifications

The available specifications for the exact LL3B400 part number didn't include specific UL, CSA, IEC, RoHS, REACH, or other certification and material-compliance information.

Where It Works Best

The LL3B400 400A circuit breaker is most relevant when the job involves existing or legacy electrical equipment that requires this three-pole LL-frame configuration.

Voltage is one of the first things to pin down. The supplied interrupting rating is 42 kA at 240VAC and 30 kA at 480VAC. For a 600VAC application, it's 22 kA. That's why simply describing the LL3B400 as having one A.I.C. rating would leave out an important part of the picture.