Siemens Q140H - 40 A, 120 V, 1-Pole Plug-In Circuit Breaker | AmpState

The Siemens Q140H is a robust 40A, 120V, 1-pole plug-in molded case circuit breaker engineered to protect branch circuits with precision. Designed for panelboards and load centers, this breaker delivers fast installation and dependable protection when and where you need it most.

• Fast plug-in connection for quick installation and easy replacement, minimizing downtime during upgrades or service calls.
• Thermal-magnetic trip unit provides stable, repeatable protection—responding to overloads and short circuits with predictable, nuisance-free performance.
• OEM-compatible design ensures a reliable fit with matching Siemens load centers and panelboards, delivering verified safety and seamless operation.
• 1-pole, 40A, 120V configuration tailored for residential, commercial, and light industrial applications requiring dedicated branch-circuit protection.
• Plug-in molded case construction combines compact form with solid protection, facilitating clean panel installation and straightforward maintenance.

What problems the Siemens Q140H solves

The Q140H shields wiring and devices from overcurrent and short circuits on branch circuits, reducing the risk of overheating and electrical fires. Its precise thermal-magnetic trip behavior helps ensure circuits disconnect promptly during faults while avoiding unnecessary trips during minor surges. This makes it an ideal choice for spaces where reliability and serviceability matter—homes, workplaces, and light manufacturing environments alike.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: Q140H
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Voltage Rating: 120V
• Number of Poles: 1
• Mounting Style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases and practical applications

• Residential subpanels protecting lighting, outlets, and dedicated circuits with straightforward plug-in replacement.
• Commercial spaces requiring reliable protection for individual branches without complex wiring changes.
• Light industrial environments where fast maintenance and dependable fault clearing are essential.
• Upgrades or retrofits in panelboards that demand compatible Siemens components for safe, code-compliant operation.

Installation tips and compatibility notes

For optimal performance, pair the Siemens Q140H with matching OEM load centers and panelboards designed for this 1-pole, 40A unit. Ensure the panel’s compatibility with plug-in molded case breakers and follow standard electrical safety practices during installation. When replacing an existing breaker, verify amperage, voltage rating, and pole count to maintain correct protection levels and circuit labeling throughout the panel.