EJB14040 - 40 Amp Circuit Breaker

EJB14040 - 40 Amp Circuit Breaker

The Square D EJB14040 is a 40 Amp, 1-pole E-Frame circuit breaker built for use in compatible Square D NF panelboards. It helps protect electrical systems from overloads and short circuits with a proven thermal-magnetic trip unit, making it a dependable option for commercial and industrial power distribution. If you're replacing an existing breaker or maintaining an electrical panel, this model offers the form, fit, and function needed for a straightforward installation.

One feature you'll appreciate during maintenance is the built-in trip indicator, which makes it easy to see when the breaker has opened due to a fault. That can save valuable time when tracking down the cause of an interruption. The bolt-on design creates a secure connection inside the panelboard, and the breaker accepts both copper and aluminum conductors, giving installers added flexibility in the field.

Key Features and Benefits

• 40 Amp, single-pole E-Frame miniature circuit breaker
• Designed for compatible Square D NF panelboards
• Thermal-magnetic trip unit provides overload and short-circuit protection
• Bolt-on mounting helps ensure a secure installation
• Built-in trip indicator allows quick visual identification after a trip
• Rated for systems up to 277 VAC
• HACR, HID, and Switching Duty rated
• Accepts copper conductors from 14–2/0 AWG and aluminum conductors from 12–2/0 AWG
• Built for long service life in demanding commercial environments

Technical Specifications

• Manufacturer: Square D
  
• Catalog Number: EJB14040
  
• Product Type: Miniature Circuit Breaker
  
• Frame Type: E-Frame
  
• Series: 125A Frame EDB/EGB/EJB
  
• Amperage: 40 Amps
  
• Poles: 1
  
• Maximum Operating Voltage: 277 VAC
  
• Trip Unit Technology: Thermal-Magnetic
  
• Trip Unit Rating: 1,800 A
  
• Holding Current: 630 A
  
• Interrupting Ratings:
  • 100 kA @ 120 VAC
  • 65 kA @ 120/240 VAC
  • 65 kA @ 240 VAC
  • 65 kA @ 277 VAC
• Mounting Style: Bolt-On
  
• Compatible Panelboards: Square D NF
  
• Protection: Overload and Short Circuit
  
• Trip Indicator: Yes
  
• Electrical Connections: Aluminum lugs
  
• Wire Range:
  • Copper: 14–2/0 AWG
  • Aluminum: 12–2/0 AWG
• Dimensions:
  • Height: 5.66 in.
  • Width: 0.98 in.
  • Depth: 4.05 in.
• Weight: 2 lb.
  

Material Compliance and Certifications

• cULus Listed
• TAA Compliant
• HACR Rated
• HID Rated
• Switching Duty Rated
• Calibrated for operation at 40°C (104°F)
• Country of Origin: Mexico
• Manufacturer's 18-Month Warranty

Where It Works Best

The Square D EJB14040 is commonly used in commercial, industrial, and institutional facilities with compatible Square D NF panelboards. It's a good fit for lighting panelboards, HVAC equipment, branch circuits, and other 277 VAC applications that require dependable circuit protection.