FD63B125L - 125Amp Circuit Breaker

FD63B125L - 125Amp Circuit Breaker

The Siemens FD63B125L is a 125 Amp, 3-pole molded case circuit breaker with a thermal-magnetic trip unit and factory-installed line and load side lugs. Built for FD-frame applications, this breaker is commonly used when your existing electrical system requires a matching breaker assembly with the same frame style, amp rating, and connection setup.

The FD63B125L is rated for 600 VAC and provides 22 kAIC at 600V and 35 kAIC at 480V interrupting capacity. It accommodates larger conductors, including 6 AWG to 350 kcmil copper and 4 AWG to 350 kcmil aluminum. With its three-pole design and standard 40°C rating, this Siemens breaker is a solid fit for commercial and industrial distribution equipment where dependable circuit protection is needed.

Key Features and Benefits

• Siemens FD-frame molded case circuit breaker
• Catalog Number: FD63B125L
• 125 Amp rating
• Three-pole configuration
• Thermal-magnetic trip unit
• Provides overload and short-circuit protection
• 600 VAC voltage rating
• Interrupting ratings:
  • 22 kAIC at 600 VAC
  • 35 kAIC at 480 VAC
• Standard 40°C breaker rating
• Factory-installed line and load side lugs
• Supports:
  • Copper conductors: 6 AWG to 350 kcmil
  • Aluminum conductors: 4 AWG to 350 kcmil
• Meets UL 489 and IEC 60947-2 standards
  

Technical Specifications

• Manufacturer: Siemens
  
• Catalog Number: FD63B125L
  
• Product Type: Molded Case Circuit Breaker
  
• Frame: FD
  
• Amperage Rating: 125 Amps
  
• Poles: 3
  
• Trip Type: Thermal-Magnetic
  
• Voltage Rating: 600 VAC
  
• Frequency: 50/60 Hz
  
• Interrupting Capacity:
  • 22 kAIC at 600 VAC
  • 35 kAIC at 480 VAC
• Terminal Type: Line and Load Side Lugs
  
• Wire Range:
  • Copper: 6 AWG – 350 kcmil
  • Aluminum: 4 AWG – 350 kcmil
• Dimensions: 4.5 in. W × 9.5 in. H × 4 in. D
  
• Weight: Approximately 10.031 lbs
  
• UPC: 783643005303
  

Material Compliance and Certifications

The Siemens FD63B125L is designed for FD-frame molded case circuit breaker applications and meets UL 489 and IEC 60947-2 standards. Before installation, confirm the breaker matches the equipment requirements, including frame type, pole configuration, voltage rating, and interrupting capacity.

Where It Works Best

The Siemens FD63B125L is commonly used in commercial buildings, industrial facilities, and electrical distribution equipment that uses compatible FD-frame molded case circuit breakers.