EF3B125 - 125Amp Circuit Breaker

EF3B125 - 125 Amp Circuit Breaker

If you’re maintaining an existing electrical system, you already know—finding the exact breaker that fits and performs like the original isn’t optional. The EF3B125 molded case circuit breaker is designed to match EF3 frame systems, giving you a straightforward, no-hassle replacement for keeping your equipment protected and operating as expected.

With a 125 amp rating and 3-pole configuration, this breaker is built for three-phase applications commonly found in commercial and industrial environments. It delivers dependable circuit protection with interruption ratings up to 14kA at 600VAC, helping manage overloads and short circuits without introducing compatibility issues. Simple, effective, and built to last—this is the kind of component that keeps your system running without drawing attention to itself.

Key Features and Benefits

• Exact Fit for EF3 Frame Systems: Designed to align with existing panel configurations
• 125 Amp Rating: Handles consistent electrical loads in demanding environments
• 3-Pole Design: Ideal for three-phase power distribution
• Solid Interrupting Capacity: Rated up to 14kA at 600VAC for fault protection
• Thermal-Magnetic Trip Mechanism: Helps protect against overloads and short circuits
• Built to Last: Made for long-term use in established electrical systems

Technical Specifications

• Part Number: EF3B125
  
• Amperage: 125A
  
• Poles: 3
  
• Frame Type: EF3
  
• A.I.C. Ratings:
  • 14kA @ 600VAC
  • 14kA @ 480VAC
  • 18kA @ 240VAC
• Operating Temperature: 40°C
  
• Type: Molded Case Circuit Breaker
  
• Height: 6.0 inches
  
• Weight: 4.5 lbs
  

Material Compliance and Certifications

• Built to meet standard industry requirements for molded case circuit breakers
• Compatible with systems designed in accordance with NEC and UL guidelines
• Suitable for use in applications requiring consistent and code-aligned circuit protection

Where It Works Best

• The EF3B125 125A circuit breaker is a practical choice for commercial buildings, industrial facilities, and maintenance environments where EF3 frame breakers are already installed. You’ll typically find it in distribution panels, control panels, and equipment protection circuits that rely on stable, three-phase power. It’s especially useful when you need a breaker that matches existing specs without requiring panel modifications or guesswork.