ND312T33W - 1200 Amp Circuit Breaker

ND312T33W - 1200 Amp Circuit Breaker

The ND312T33W is a 1200-amp, 3-pole N-Frame circuit breaker for compatible electrical distribution equipment. If you're working on an existing Type ND installation, the important details are straightforward: this is a molded-case electronic breaker with a non-interchangeable trip unit, adjustable short-time pickup, and an I²t short-delay ramp. It is also specified as thermal-magnetic and HACR-rated.

Interrupting capacity depends on system voltage. The ND312T33W is rated 25k AIC at 600VAC, 50k AIC at 480VAC, and 65k AIC at 240VAC. Physically, it measures 16 inches high, 8.25 inches wide, and 5.5 inches deep.

For replacement work, those specifications matter just as much as the part number. Before installation, check the frame, dimensions, pole count, amperage, voltage, interrupting rating, and trip requirements against the existing equipment. Also note that the rating plug and lug terminals are not included in the catalog number. Built to last for its intended application, the ND312T33W is well suited to maintaining compatible legacy equipment when the correct form, fit, and function must be preserved.

Key Features and Benefits

• 1200-amp, 3-pole configuration for compatible Type ND applications
• N-Frame molded case design for matching existing equipment requirements
• Electronic, non-interchangeable trip unit
• Adjustable short-time pickup with I²t short-delay ramp
• Specified as thermal magnetic
• HACR-rated
• 25k AIC at 600VAC
• 50k AIC at 480VAC
• 65k AIC at 240VAC
• Clearly defined dimensions help with form-and-fit verification
• Suitable for replacement and maintenance work in compatible legacy systems
  

Technical Specifications

• Part Number: ND312T33W
  
• Type: ND
  
• Frame: N-Frame
  
• Amperage: 1200A
  
• Poles: 3
  
• Breaker Style: Molded Case Electronic Circuit Breaker
  
• Trip Unit: Non-Interchangeable
  
• Specification: Thermal Magnetic
  
• 600VAC Interrupting Rating: 25k AIC
  
• 480VAC Interrupting Rating: 50k AIC
  
• 240VAC Interrupting Rating: 65k AIC
  
• Short-Time Pickup: Adjustable
  
• Short Delay: I²t Ramp
  
• Height: 16.0 in.
  
• Width: 8.25 in.
  
• Depth: 5.5 in.
  
• Rating Plug: Not included in catalog number
  
• Lug Terminals: Not included in catalog number
  

Material Compliance and Certifications

• The supplied specifications identify the ND312T33W as HACR rated. No other material compliance or certification information was provided, so do not assume additional compliance claims without supporting product documentation.
  

Where It Works Best

• The ND312T33W makes the most sense in existing electrical systems that require a Type ND, N-Frame, 1200A, 3-pole breaker with matching trip characteristics and interrupting ratings. That makes it particularly relevant for maintenance and form-fit-function replacement work involving compatible legacy electrical distribution equipment.
• Check compatibility against the equipment already in place. Confirm the frame size, dimensions, amperage, number of poles, system voltage, AIC requirement, trip functions, rating plug, and terminal arrangement before installation. This keeps the focus where it belongs: matching the breaker to the system's actual electrical and mechanical requirements.