EJB34040 - 40 Amp Circuit Breaker

EJB34040 - 40 Amp Circuit Breaker

When your dependable circuit protection matters, the Square D EJB34040 is built for the job. This 40 Amp, 3-pole E-Frame circuit breaker is made for use in compatible Square D NF panelboards, helping protect electrical systems from overloads and short circuits. Its thermal-magnetic trip mechanism responds to both sustained overload conditions and sudden fault currents, while the built-in trip indicator makes it easy to see when the breaker has operated. With a maximum operating voltage of 480Y/277V AC and interrupting ratings up to 100 kA at applicable voltages, the EJB34040 is well-suited for demanding commercial and industrial electrical systems. It is also HACR- and HID-rated, making it appropriate for qualifying HVAC equipment and high-intensity discharge lighting applications.

Key Features and Benefits

• 40 Amp current rating
• Three-pole design for three-phase electrical systems
• Bolt-on mounting for compatible Square D NF panelboards
• Thermal-magnetic trip unit protects against overloads and short circuits
• Built-in trip indicator simplifies troubleshooting
• Rated for systems up to 480Y/277V AC
• Interrupting capacity up to 100 kA at applicable voltage ratings
• HACR and HID rated
• Accepts copper and aluminum conductors
• Calibrated for operation in 40°C (104°F) ambient conditions

Technical Specifications

• Manufacturer: Square D
  
• Catalog Number: EJB34040
  
• Series: 125A Frame EDB / EGB / EJB
  
• Frame Type: E-Frame
  
• Current Rating: 40 Amps
  
• Poles: 3
  
• Maximum Voltage: 480Y/277V AC
  
• Mounting Style: Bolt-On
  
• Trip Unit: Thermal-Magnetic
  
• Protection: Overload and Short Circuit
  
• Trip Unit Rating: 1800 A
  
• Holding Current: 630 A
  
• Interrupting Ratings:
  • 100 kA @ 120V AC
  • 100 kA @ 120/240V AC
  • 100 kA @ 240V AC
  • 65 kA @ 277V AC
  • 65 kA @ 480Y/277V AC
• Wire Range:
  • Copper: AWG 14–2/0
  • Aluminum: AWG 12–2/0
• Connections: Aluminum lugs
  
• Compatible Equipment: Square D NF Panelboards
  
• Dimensions:
  • Height: 5.66 in. H
  • Width: 2.94 in. W
  • Depth: 4.05 in. D
• Weight: Approximately 4 lbs
  

Material Compliance and Certifications

The Square D EJB34040 is cULus Listed, HACR rated, HID rated, and TAA compliant. It is calibrated for operation in ambient temperatures up to 40°C (104°F) and is intended for use in compatible Square D NF panelboards. Always install electrical equipment in accordance with the National Electrical Code (NEC) and local regulations.

Where It Works Best

• Square D NF panelboards
• Commercial buildings
• Industrial facilities
• Office buildings
• Schools and universities
• Healthcare facilities
• Warehouses and distribution centers
• HVAC equipment
• HID lighting systems
• Electrical maintenance and retrofit projects