Square D QO340VH - 40 A, 240 V, 3-Pole Plug-In Circuit Breaker | AmpState

Square D QO340VH is a 40A, 240V, 3-pole plug-in molded case circuit breaker designed to deliver reliable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Built for quick installations and straightforward replacements, this unit keeps electrical systems safe with minimal downtime.

Key features that set the QO340VH apart:

• Fast plug-in connection: enables rapid installation and easy replacement in compatible Square D panelboards, reducing service time on upgrades or repairs.
• Thermal-magnetic trip unit: provides stable, repeatable protection by responding to both overload conditions and short circuits, helping prevent nuisance trips and equipment damage.
• OEM compatibility: engineered to work seamlessly with matching Square D OEM load centers and panelboards for dependable performance and proper fit.
• Versatile, residential to light industrial: ideal for a wide range of applications that require 40A at 240V across 3 poles, from home electrical upgrades to commercial and light industrial circuits.

Technical snapshot

• Manufacturer: Square D
• Part Number: QO340VH
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Plug-in
• Applications: Branch circuit overcurrent and short-circuit protection

Why choose this 3-pole 240V plug-in breaker? The design supports multi-wire and three-phase configurations common in today’s electrical panels, while the plug-in format minimizes installation errors and downtime. The thermal-magnetic trip curve delivers dependable protection across varying loads and temperatures, helping you maintain safe, continuous operation of connected equipment.

Use scenarios:

• Upgrading or expanding residential panels to accommodate new 240V circuits (heaters, large appliances, or EV charging circuits).
• Equipping small commercial panelboards to safeguard lighting, receptacle, and equipment circuits.
• Supplementing light industrial panels where quick servicing and robust protection are essential.

Practical tips for installation and maintenance: verify that your panelboard is compatible with the QO series plug-in breakers, ensure the panel is rated for 240V 3-pole devices, and keep spare breakers on hand to minimize downtime during future service needs. With the Square D QO340VH, you gain a dependable, OEM-aligned solution that keeps your electrical system protected and running smoothly.