Square D EJB14045 - 45 A, 277 V, 1-Pole Bolt-On Circuit Breaker | AmpState

The Square D EJB14045 is a purpose-built 45-ampere, 277-volt, 1-pole bolt-on molded case circuit breaker designed to deliver reliable branch-circuit protection in panelboards and load centers. Built to stand up to the demands of residential, commercial, and light industrial environments, this breaker pairs straightforward installation with dependable protection, helping you keep circuits safe and equipment protected.

Key advantages that set this breaker apart

• Secure bolt-on mounting for a rigid, vibration-resistant bus connection that stays solid through motor starts and routine panel activity.
• Thermal-magnetic trip unit provides stable, repeatable protection for both overcurrent and short-circuit events, helping to minimize nuisance trips while preserving circuit integrity.
• OEM-compatible design ensures seamless compatibility with matching Square D load centers and panelboards, simplifying replacements and upgrades.
• Versatile applicability suited for residential, commercial, and light industrial circuits, giving you a single, reliable solution across various installations.
• Molded case reliability combines durable construction with predictable performance over time, reducing maintenance needs in demanding electrical environments.

Technical specifications at a glance

• Manufacturer: Square D
• Part number: EJB14045
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 45 A
• Voltage rating: 277 V
• Number of poles: 1
• Mounting style: Bolt-on
• Primary application: Branch circuit overcurrent and short-circuit protection

Use cases and practical benefits

Designed for panelboards and load centers, the EJB14045 excels wherever a dedicated 45A protective device is needed for a single-channel circuit. In residential settings, it can safeguard critical branch circuits feeding lighting, outlets, or small appliances. In commercial environments, it’s well-suited for lighting panels, receptacle banks, or simple HVAC controls that require dependable protection without frequent maintenance.

The bolt-on mounting delivers a more robust connection than non-bolt-on options, reducing the risk of loose connections in vibration-prone installations or in spaces with regular equipment start-up. The thermal-magnetic trip mechanism ensures quick, predictable responses to faults, helping to prevent damage to wiring and connected equipment while supporting safe disconnection during abnormal conditions.

Installation, compatibility, and best practices

For installers and maintenance professionals, this breaker pairs with matching OEM load centers and panelboards from Square D, ensuring a clean, reliable fit. When replacing an existing 45 A device in a compatible panel, this unit provides a straightforward bolt-on swap with familiar field service procedures. Always verify that the panelboard is rated for bolt-on molded case breakers of the EJB family and that the circuit design aligns with 277 V operation requirements.

Why choose this Square D breaker over alternatives

If you need a dependable, single-pole protection solution that combines secure mounting with precise thermal-magnetic trip performance, the EJB14045 is purpose-built for that role. Its bolt-on design minimizes movement and vibration-induced wear, while the integrated trip unit offers reliable protection tailored to real-world load profiles. When you require compatibility with Square D’s panel ecosystems and a device that supports consistent protection across a range of commercial and light industrial applications, this model delivers focused, durable performance.

In short, the Square D EJB14045 is a precise, robust, and panel-ready choice for safeguarding branch circuits in diverse settings, delivering dependable protection where it matters most.