FD63B125 - 125Amp Circuit Breaker

FD63B125 - 125Amp Circuit Breaker

The Siemens FD63B125 is a 125 Amp, 3-pole molded case circuit breaker built for FD-frame applications. It features a thermal-magnetic trip unit and factory-installed line- and load-side lugs, making it a complete breaker assembly for your compatible electrical distribution equipment.

This FD-frame breaker is rated for 600 VAC and provides 22 kAIC at 600V and 35 kAIC at 480V interrupting capacity. It supports larger conductors, including 6 AWG to 350 kcmil copper and 4 AWG to 350 kcmil aluminum.

Key Features and Benefits

• Siemens FD-frame molded case circuit breaker
• Catalog Number: FD63B125
• 125 Amp rating
• Three-pole configuration
• Thermal-magnetic trip unit
• Provides overload and short-circuit protection
• Rated for 600 VAC
• 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

Technical Specifications

• Manufacturer: Siemens
  
• Catalog Number: FD63B125
  
• Product Type: Molded Case Circuit Breaker
  
• Frame: FD
  
• Amperage Rating: 125 Amps
  
• Poles: 3
  
• Trip Type: Thermal-Magnetic
  
• Voltage Rating: 600 VAC
  
• Frequency Rating: 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 10.516 lbs
  
• UPC: 783643211469
  

Material Compliance and Certifications

The Siemens FD63B125 is designed for FD-frame molded case circuit breaker applications and meets UL 489 and IEC 60947-2 standards. Before installation, confirm that the breaker matches the equipment requirements, including frame type, voltage rating, pole configuration, and interrupting capacity.

Where It Works Best

The Siemens FD63B125 is commonly used in commercial buildings, industrial facilities, and electrical distribution systems that use compatible FD-frame molded case circuit breakers.