Square D DJM32400E20 - 400 A, 208 V, 3-Pole Bolt-On Circuit Breaker | AmpState

The Square D DJM32400E20 is a rugged 400A, 208V, 3-pole bolt-on molded case circuit breaker designed to protect electrical distribution in panelboards and loadcenters. Built for dependable branch circuit overcurrent and short-circuit protection, it’s a smart choice for larger residential setups, commercial spaces, and light industrial applications where uptime matters.

• Bolt-on mounting delivers a secure, vibration-resistant bus connection for lasting reliability in panels that experience environmental movement or mounting flex.
• Thermal-magnetic trip unit provides stable, repeatable protection—thermal sensing handles gradual overloads, while the magnetic element quickly clears high-energy faults, reducing the risk of damage to conductors and equipment.
• OEM-compatible design is engineered to pair with matching Square D OEM panelboards and loadcenters, ensuring a clean fit and straightforward replacement without modification.
• High-capacity protection at 400A and 208V makes it suitable for main feeders and large branch circuits, delivering robust protection where it’s most needed.
• Versatile application ideal for residential, commercial, and light industrial installations that require reliable 3-pole protection in 208V systems.

Key specifications at a glance

• Manufacturer: Square D
• Part Number: DJM32400E20
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400 A
• Voltage Rating: 208 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Why this breaker stands out

In environments where panel integrity and reliable protection are non-negotiable, the DJM32400E20’s bolt-on design minimizes movement-induced contact wear, while the thermal-magnetic trip delivers predictable response to both sustained overloads and sudden faults. The result is fewer nuisance trips during busy, fluctuating loads and longer panel life, especially in commercial and light industrial settings where 208V distribution is common.

Ideal use cases

• Main feeder protection in commercial panelboards and industrial loadcenters
• Replacement or upgrade for 400A, 208V, 3-pole circuits in OEM-compatible panels
• Subpanel protection where robust, reliable trip characteristics are required
• Residential-commercial mixed-use installations with 208V distribution requirements

Installation and compatibility tips

Choose this breaker when you need a seamless fit with Square D OEM panelboards and loadcenters. Ensure the panel is rated for 400A and 208V service, and follow proper lockout/tagout procedures during installation. The bolt-on design simplifies field replacement and maintenance, helping reduce installation time and downtime during service outages.