Siemens CQD140 - 40 A, 277 V, 1-Pole Circuit Breaker | AmpState

The Siemens CQD140 is a 40A, 277V, 1-pole molded-case circuit breaker built to deliver reliable branch-circuit overcurrent and short-circuit protection in panelboards and load centers. Its compact molded-case design helps you maximize panel space, letting you fit more protection where it matters most while maintaining clean, organized wiring routes.

• Space-efficient design: The molded-case construction is engineered to minimize footprint, enabling tighter panel layouts without compromising protection.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection by responding quickly to overloads and short-circuits, reducing nuisance trips and improving reliability across varying loads.
• OEM-compatible reliability: Designed to pair seamlessly with matching Siemens OEM load centers and panelboards, ensuring coordinated protection and predictable performance.
• Versatile application: Suitable for residential, commercial, and light industrial electrical systems, especially 277V circuits common in commercial lighting and power distribution.

Key benefits you can expect with the CQD140 include longer service life through precise thermal-magnetic protection, simplified panel planning due to its compact form factor, and a straightforward replacement path when upgrading or expanding existing panelboards. By choosing a 1-pole 40A breaker rated at 277V, you’re safeguarding individual branch circuits against overloads and short circuits while preserving clarity and ease of maintenance in your electrical distribution system.

Specifications at a glance

• Manufacturer: Siemens
• Part Number: CQD140
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Voltage Rating: 277V
• Number of Poles: 1
• Application: Branch circuit overcurrent and short-circuit protection

Whether you’re upgrading an older panel, expanding a commercial storefront, or configuring a new subpanel in a light industrial setting, the CQD140 offers a dependable, well-supported solution. Its combination of compactness, precise protection, and OEM compatibility makes it a practical choice for standard 277V branch circuits that require consistent performance and straightforward installation.