Square D EJB24040 - 40 A, 480 V, 2-Pole Bolt-On Circuit Breaker | AmpState

The Square D EJB24040 is a 40 A, 480 V, 2-pole bolt-on molded case circuit breaker built to deliver reliable branch circuit overcurrent and short‑circuit protection in panelboards and loadcenters. With a thermal‑magnetic trip unit, it provides stable, repeatable protection across a wide range of operating conditions, helping you avoid nuisance trips while safeguarding your electrical distribution.

Why this breaker stands out

• Secure bolt-on mounting: A robust attachment to the bus connection minimizes vibration and maintains a dependable electrical path even in environments with machinery or intermittent movement.
• Thermal-magnetic trip unit: Combines thermal overload sensing with instantaneous magnetic protection for fast response to short circuits, reducing damage to downstream loads.
• OEM-compatible: Designed to be compatible with matching OEM loadcenters and panelboards, simplifying replacement or retrofits when upgrading or expanding a system.
• Versatile application: Suitable for residential, commercial, and light industrial circuits, making it a practical choice for diverse distribution needs.
• Clear electrical ratings: 40 A current rating with a 480 V rating ensures appropriate protection for mid‑sized feeder and branch circuits in higher‑voltage installations.

What this means in your panel

Use the EJB24040 to protect a single branch circuit or as part of a broader protection strategy in panelboards and loadcenters. The bolt-on design simplifies installation in existing enclosures, and the two‑pole construction provides coordinated protection for both conductors in 240 V systems and other configurations that require simultaneous disconnection of two live lines. By selecting a breaker that matches your system’s voltage and current requirements, you help ensure reliable interruption during fault events while maintaining compliant protection margins.

Technical specifications at a glance

• Manufacturer: Square D
• Part Number: EJB24040
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40 A
• Voltage Rating: 480 V
• Number of Poles: 2
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases

• New installations in panelboards or loadcenters requiring robust 2-pole protection at 480 V
• Replacement or retrofit projects where OEM compatibility ensures seamless integration
• Commercial and light industrial electrical distributions with higher voltage requirements
• Residential projects that demand durable, vibration-resistant breakers in shared service panels

Installation and compatibility notes

For dependable performance, pair the EJB24040 with the corresponding OEM loadcenter or panelboard model designed to accept bolt-on molded case breakers. Ensure proper tightening of mounting hardware to maintain the vibration resistance that protects bus connections, and verify that the circuit's amperage and voltage align with the panel’s specifications and local electrical codes.