Square D EJB34040 - 40 A, 480 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Introducing the Square D EJB34040—a 40 A, 480 V, 3‑pole bolt‑on molded case circuit breaker built to deliver dependable branch circuit protection in panelboards and load centers. Designed for demanding 3‑phase environments, this unit neutralizes overloads and short circuits with precise, repeatable performance while withstanding the rigors of busy electrical rooms.

Why this breaker stands out

• Secure bolt‑on mounting creates a rigid, vibration‑resistant bus connection that stays put through temperature changes and equipment vibration—minimizing wear and maintaining reliable protection.
• Thermal‑magnetic trip unit combines thermal overload sensing with instantaneous magnetic action, delivering stable, repeatable protection across varying loads and fault conditions.
• 3‑pole, 480 V capacity is tailored for 3‑phase panelboards and load centers common in commercial and light industrial settings, enabling safe control of motors and equipment.
• OEM compatibility ensures seamless integration with matching Square D OEM load centers and panelboards, reducing installation guesswork and ensuring coordinated protection schemes.
• Versatility across applications suitable for residential, commercial, and light industrial installations—perfect for motor controllers, lighting branches, and general distribution circuits.

What problems it solves

By delivering predictable tripping behavior, the EJB34040 helps protect wiring, components, and connected equipment from damaging overloads and short circuits. The rugged bolt‑on design minimizes connection loosening over time, which translates to fewer nuisance trips and more consistent protection on busy electrical systems.

Technical snapshot

• Manufacturer: Square D
• Part Number: EJB34040
• Type: Thermal‑magnetic molded case circuit breaker
• Amperage Rating: 40 A
• Voltage Rating: 480 V
• Number of Poles: 3
• Mounting Style: Bolt‑on
• Application: Branch circuit overcurrent and short‑circuit protection

Ideal for

• 3‑phase panelboards and load centers in commercial facilities
• Light industrial electrical distributions and motor circuits
• Residential–commercial transitions where robust 3‑pole protection is required

If you’re upgrading or provisioning a 3‑phase electrical distribution, the Square D EJB34040 delivers reliable protection with a secure, vibration‑resistant mount, precise trip performance, and firmware‑friendly compatibility with Square D OEM panels. It’s a practical choice for electricians and facilities professionals seeking durable, industry‑standard protection at 480 V.