MD63T800 - 800Amp Trip Unit

MD63T800 - 800Amp Trip Unit

When your existing MD-frame breaker calls for 700A? No—this is exactly why catalog-level accuracy matters. The MD63T800 is an 800-amp, 3-pole thermal-magnetic trip unit intended for compatible MD-frame circuit breaker equipment. The manufacturer's catalog description specifically identifies this part as "TU ONLY," meaning trip unit only, so it should not be confused with a complete molded case circuit breaker. When all required specifications match, the MD63T800 can be considered a form, fit, and functional replacement candidate for compatible existing or legacy MD-frame equipment. Its solid construction is built to last when selected, assembled, installed, and maintained correctly.

Key Features and Benefits

• 800A Trip Unit: The MD63T800 carries an 800 amp rating, an important specification when matching an existing MD-frame application.
• Thermal-Magnetic Configuration: Built around the specified thermal-magnetic trip design used with compatible MD-frame breaker equipment.
• MD-Frame Application: Specifically identified as a trip unit for the MD frame, helping narrow replacement selection by frame type rather than relying on amperage alone.
• Three-Pole Configuration: Manufacturer data associates the trip unit with an 800A, 3-pole breaker configuration.
• Trip Unit Only: The catalog description states TU ONLY. The MD63T800 is a trip unit, not a complete breaker assembly.
• Straightforward Replacement Matching: Catalog number, frame, amperage, pole count, and trip type provide useful details for checking compatibility with existing equipment.

Technical Specifications

• Catalog Number: MD63T800
  
• Article Number: US2\:MD63T800
  
• Manufacturer Catalog Description: BREAKER MD 3P 800A 600V 25KA TU ONLY
  
• Product Type: Thermal-Magnetic Trip Unit
  
• Configuration: TU Only / Trip Unit Only
  
• Product Family: MD6, 25KAIC, 600VAC
  
• Frame: MD
  
• Amperes: 800A
  
• Poles: 3
  
• Associated Voltage Rating: 600V
  
• Associated AIC Rating at 600V: 25kAIC
  
• Associated AIC Rating at 480V: 50kAIC
  
• Trip Type: Thermal-Magnetic
  
• Breaking Capacity: Standard Breaking Capacity
  
• Net Weight: 6.1 lb
  
• UPC: 783643214842
  
• Commodity Code: 85363099
  
• Country of Origin: Mexico
  
• Associated Lug Type Referenced: TA3K500
  
• Associated Lug Position: Line and load side
  
• Associated Wire Range: 1/0 AWG–500 KCM
  
• Associated Conductor Compatibility: Copper/Aluminum (CU/AL)
  
• Associated Breaker Dimensions (W x H x D): 9 x 16 x 6 in.
  

Material Compliance and Certifications

The supplied manufacturer information states that the associated low-voltage molded case circuit breaker configuration meets UL 489 and IEC 60947-2 standards. Because MD63T800 is identified specifically as a trip unit, those standards are best presented in the context of the complete breaker configuration rather than as an unsupported claim of independent trip-unit certification.

Where It Works Best

The MD63T800 800 amp thermal-magnetic trip unit is best considered for replacement and maintenance applications involving compatible existing or legacy MD-frame electrical equipment that specifically requires this trip-unit configuration. Rather than choosing by amperage alone, compare the existing equipment with the MD63T800 catalog number, MD frame, 800A rating, three-pole configuration, thermal-magnetic trip requirements, voltage, and associated interrupting ratings.

Because this is a trip unit only, identify and evaluate the remaining breaker components separately. In particular, don't assume that the referenced TA3K500 line- and load-side lugs, 1/0 AWG–500 KCM CU/AL conductor range, or complete-breaker dimensions describe what physically comes with the MD63T800.