MDL3300L - 300 Amp Circuit Breaker

MDL3300L - 300 Amp Circuit Breaker

When you're matching a replacement breaker, the details after the basic amp rating matter. The MDL3300L is a 300-amp, 3-pole MDL thermal-magnetic circuit breaker with an interchangeable trip unit, a 40°C rating, and HACR rating. For existing or legacy electrical equipment that calls for these specifications, the MDL3300L can be considered a form, fit, and functional replacement candidate when all electrical, dimensional, trip, and terminal requirements match. Its solid construction is built to last when selected, installed, and maintained correctly.

Key Features and Benefits

• 300A, 3-Pole Configuration: Matches applications specifically requiring a 300 amp MDL breaker with three poles.
• Thermal-Magnetic Trip Design: The MDL3300L uses the specified thermal-magnetic circuit breaker configuration.
• Interchangeable Trip Unit: The supplied configuration includes an interchangeable trip unit, making this a key detail to match against existing MDL equipment.
• Line and Load Terminals Included: The MDL3300L includes both line and load terminals. No terminal material or conductor range was supplied, so verify those details separately.
• 40°C Rated: The supplied specifications identify the breaker as 40°C rated.
• HACR Rated: This model lists a HACR rating.

Technical Specifications

• Part Number: MDL3300L
  
• Product Type: Thermal-Magnetic Circuit Breaker
  
• Type: MDL
  
• Amperes: 300A
  
• Poles: 3
  
• A.I.C. Rating at 600VAC: 25kAIC
  
• A.I.C. Rating at 480VAC: 50kAIC
  
• A.I.C. Rating at 240VAC: 65kAIC
  
• Trip Type: Thermal-Magnetic
  
• Trip Unit: Interchangeable
  
• Temperature Rating: 40°C
  
• HACR Rated: Yes
  
• Included Terminals: Line and load terminals
  
• Height: 16.00 in.
  
• Width: 8.25 in.
  
• Depth: 4.06 in.
  
• Dimensions: 8.25"W x 16.00"H x 4.06"D
  
• Approx. Ship Weight: 35.00 lbs.
  

Material Compliance and Certifications

The available specifications explicitly identify the MDL3300L as HACR rated. No additional certification or material-compliance information, such as UL, IEC, RoHS, or REACH status, was supplied for this exact catalog number. Rather than assuming specifications from another MDL breaker also apply, verify any additional certification or compliance requirements for the MDL3300L itself.

Where It Works Best

The MDL3300L 300 amp circuit breaker is a practical replacement candidate for compatible existing or legacy electrical equipment that specifically requires an MDL-type, 3-pole, 300A thermal-magnetic circuit breaker with an interchangeable trip unit. The included line and load terminals should also match the existing equipment's connection requirements.

Check voltage and interrupting capacity together. The MDL3300L is rated 25kAIC at 600VAC, 50kAIC at 480VAC, and 65kAIC at 240VAC. Physical compatibility matters just as much, so compare the supplied 8.25"W x 16.00"H x 4.06"D dimensions with the existing installation.