EJB24125 - 125 Amp Circuit Breaker

EJB24125 - 125 Amp Circuit Breaker

When dependable circuit protection is critical, the Square D EJB24125 is built to handle the job. This 125 Amp, 2-pole E-Frame circuit breaker is made for use in compatible Square D NF panelboards, where it helps protect electrical systems from overloads and short circuits. Its thermal-magnetic trip unit responds to changing electrical conditions, providing dependable protection during both sustained overloads and sudden fault events.

The bolt-on mounting design creates a secure connection inside the panelboard, while the built-in trip indicator makes it easy to see when the breaker has opened because of a fault. That can save valuable time during troubleshooting and routine maintenance. Rated for systems up to 480Y/277V AC with interrupting capacities as high as 100 kA on applicable voltage systems, the EJB24125 is a solid choice for commercial buildings, industrial facilities, and other demanding electrical installations.

If you're replacing an existing E-Frame breaker in a compatible NF panelboard, the EJB24125 lets you maintain the original panel configuration while restoring dependable branch circuit protection.

Key Features and Benefits

• 125 Amp current rating
• Two-pole configuration for dependable branch circuit protection
• Bolt-on mounting for compatible Square D NF panelboards
• Thermal-magnetic trip unit provides reliable overload and short-circuit protection
• Built-in trip indicator simplifies fault identification and maintenance
• Rated for systems up to 480Y/277V AC
• Interrupting ratings up to 100 kA on applicable voltage systems
• HACR rated for qualifying HVAC and refrigeration equipment
• Accepts both copper and aluminum conductors for installation flexibility

Technical Specifications

• Manufacturer: Square D
  
• Catalog Number: EJB24125
  
• Series: EDB / EGB / EJB 125A Frame
  
• Device Short Name: EJB
  
• Frame Type: E-Frame
  
• Product Type: Thermal-Magnetic Circuit Breaker
  
• Current Rating: 125 Amps
  
• Poles: 2
  
• Maximum Operating Voltage: 480Y/277V AC
  
• Mounting Style: Bolt-On
  
• Panel Compatibility: Square D NF Panelboards
  
• Trip Unit Technology: Thermal-Magnetic
  
• Trip Current: 2300 Amps
  
• Holding Current: 1000 Amps
  
• Protection: Overload and Short Circuit
  
• Trip Indicator: Yes
  
• Breaking Capacity:
  • 100 kA @ 120V AC
  • 100 kA @ 120/240V AC
  • 100 kA @ 240V AC
  • 65 kA @ 277V AC
  • 65 kA @ 480Y/277V AC
• Breaking Capacity Code: J
  
• Wire Range:
  • Copper: AWG 14–2/0
  • Aluminum: AWG 12–2/0
• Terminal Type: Aluminum Lugs
  
• Tightening Torque:
  • 34.5 lb-in (3.9 N·m) for AWG 14–10
  • 49.6 lb-in (5.6 N·m) for AWG 8–2/0
• Number of Spaces Required: 2
  
• Calibration Temperature: 40°C (104°F)
  
• Dimensions:
  • Height: 5.66 in H
  • Width: 1.96 in W
  • Depth: 4.05 in D
• Weight: 3 lb
  
• Warranty: 18 Months
  

Material Compliance and Certifications

The Square D EJB24125 is cULus Listed and HACR rated, meeting recognized North American safety standards for qualifying applications. It is calibrated for operation in ambient temperatures up to 40°C (104°F) and is intended for installation in compatible Square D NF panelboards. Installation should always be performed by qualified electrical personnel in accordance with the National Electrical Code (NEC), local electrical regulations, and applicable safety requirements.

Where It Works Best

• Square D NF panelboards
• Commercial lighting panelboards
• 480Y/277V AC branch circuits
• Office buildings
• Manufacturing facilities
• Healthcare facilities
• Educational campuses
• Retail stores and shopping centers
• Warehouses and distribution centers
• HVAC and refrigeration systems