JD63B300 - 300Amp Circuit Breaker

JD63B300 - 300Amp Circuit Breaker

When considering the Siemens JD63B300 300-amp circuit breaker, it's important to note its key features. This three-pole molded-case circuit breaker has a JD frame, a thermal-magnetic trip unit, and is rated for 40°C. It measures 7.5 inches wide, 11 inches high, and 4 inches deep, so be sure to compare these dimensions with your existing setup. While built for durability, ensure that factors like frame type, ratings, size, trip type, and connections are compatible for a successful replacement.

Key Features and Benefits

• A 300A rating and three poles make it easy to verify the basic electrical configuration against the existing breaker.
• JD frame provides another important compatibility point when checking form and fit.
• Uses a thermal-magnetic trip unit as specified by Siemens.
• Identified as a standard 40°C breaker.
• TA2J6500 lugs are included on the load sides, so the connection arrangement is clearly defined.
• Handles 3/0 AWG through 500 kcmil copper conductors.
• Handles 4/0 AWG through 500 kcmil aluminum conductors.
  

Technical Specifications

• Catalog Number / MFN: JD63B300
  
• Article Number: US2:JD63B300
  
• Manufacturer: Siemens
  
• Product Line: SENTRON
  
• Product Family: JD6, 25 kAIC, 600VAC
  
• Product Type: Molded Case Circuit Breaker
  
• Frame: JD
  
• Amperage: 300 A
  
• Poles: 3
  
• Voltage: 600V
  
• Trip Unit: Thermal-magnetic
  
• Temperature Rating: Standard 40°C
  
• Interrupting Rating at 600V: 25 kAIC
  
• Interrupting Rating at 480V: 35 kAIC
• Load-Side Lugs: TA2J6500
  
• Copper Wire Range: 3/0 AWG–500 kcmil
  
• Aluminum Wire Range: 4/0 AWG–500 kcmil
  
• Dimensions: 7.5" W x 11" H x 4" D
  
• UPC: 783643213197
  
• Country of Origin: Mexico
  
• Standards: UL 489 and IEC 60947-2
  

Material Compliance and Certifications

Siemens states that the JD63B300 meets UL 489 and IEC 60947-2 standards. The supplied information does not specifically identify this catalog number as UL Listed, so it is better to keep the wording to the manufacturer's stated standards rather than make a broader certification claim.

Where It Works Best

The JD63B300 meets the needs of compatible existing and legacy equipment that calls for this particular combination of 300A capacity, three-pole configuration, JD frame, thermal-magnetic trip unit, and 600V rating. It's especially useful to check the lug setup when matching an existing installation, since this model comes with TA2J6500 lugs on both sides and has defined conductor ranges for copper and aluminum wire.