EF3B040 - 40 Amp Circuit Breaker

EF3B040 - 40 Amp Circuit Breaker

If you’re working on an existing electrical system and need a circuit breaker that fits right the first time, the EF3B040 is built for exactly that purpose. Designed for EF3 frame applications, this 40-amp, 3-pole molded case circuit breaker makes it easier to replace a worn or faulty unit without second-guessing compatibility. It’s a straightforward solution for maintaining your system’s protection—helping guard against overloads and short circuits while keeping your equipment running as intended. Whether you’re servicing a commercial panel or handling routine maintenance in an industrial setup, this breaker is made to drop into place and do its job without unnecessary complications.

Key Features and Benefits

• Exact Fit for EF3 Frame Systems – Designed to align with existing panel configurations, reducing install time
• 40 Amp Capacity – Ideal for protecting moderate-load circuits in commercial and industrial settings
• 3-Pole Design – Supports three-phase power distribution
• Thermal-Magnetic Trip Mechanism – Helps respond to both sustained overloads and sudden faults
• Calibrated for 40°C Environments – Matches standard operating conditions found in most electrical rooms
• Built to Last – Solid construction designed for long-term use in working electrical systems

Technical Specifications

• Part Number: EF3B040
• Amperage: 40A
• Number of Poles: 3
• Frame Type: EF3
• Interrupting Capacity (A.I.C.):
  • 14kA @ 600VAC
  • 14kA @ 480VAC
  • 18kA @ 240VAC
• Temperature Rating: 40°C
• Breaker Type: Molded Case Circuit Breaker
• Dimensions (Approx.): 6.0" height
• Weight: 4.5 lbs

Material Compliance and Certifications

• Industry Standards: This circuit breaker is built in line with standard industry requirements for molded case breakers, including proper insulation and interrupting ratings.
• Installation Guidance: It is intended for use within its specified limits and should be installed in accordance with local electrical codes and regulations.

Where It Works Best

• Commercial buildings with existing EF3 panel setups
• Industrial facilities maintaining three-phase power systems
• Electrical distribution panels requiring a 40A, 3-pole breaker
• Maintenance and repair projects where matching the original breaker is critical