Square D 992140 40A 1-Pole 120 V Circuit Breaker

Meet the Square D 992140 40A 1-Pole 120 V Circuit Breaker — a genuine Square D protection device engineered to safeguard a dedicated 120-volt circuit. With a precise 40-amp rating and a single-pole design, this breaker provides reliable overcurrent protection for individual loads while fitting seamlessly into compatible Square D panels. Part number 992140 identifies the exact component you need for replacement or upgrade, helping you maintain consistent electrical performance across your system.

Key specifications at a glance

• Current rating: 40 A
• Poles: 1
• Voltage rating: 120 V
• Brand: Square D
• Part number: 992140

What makes this 992140 stand out

This isn’t a generic breaker. The Square D 992140 is built to match Square D’s engineering standards, delivering dependable protection for a specific 120V circuit. Its 1-pole construction means it interrupts only the hot conductor for a single circuit, helping you isolate and protect individual loads without unnecessary disruption to other circuits. Using the exact part number ensures compatibility with Square D panels and the expected trip characteristics, so you can trust it to perform when it matters most.

Ideal use cases

• Dedicated 120V branch circuits in workshops or garages that require up to 40 amps of protection
• Heavy-load 120V devices such as large power tools, compressors, or high-draw equipment that operate on a single hot conductor
• Replacement for a failed or worn-out 1-pole 40A breaker in compatible Square D panels
• Residential or light commercial electrical setups where precise, single-circuit protection is essential

Why it solves real-world problems

Overcurrent protection prevents wiring insulation damage and reduces the risk of electrical fires by shutting the circuit down before overheating occurs. The 40A rating is chosen for loads that draw significant current, while the 1-pole configuration keeps installation straightforward in 120V circuits. By using the exact Square D 992140, you’re selecting a component designed to work reliably with your existing panel architecture, minimizing compatibility issues and easing future maintenance.

Installation and safety tips

• Power down the main breaker before removing or installing a new 1-pole breaker
• Verify that the circuit’s wiring gauge and load align with a 40A protection device (typically matching ampacity to the wire size)
• Install only in panels that specify compatibility with Square D 1-pole breakers of this type
• Ensure proper seating on the bus and secure connections to prevent arcing or intermittent tripping
• Label the circuit clearly after installation to reflect its purpose and load

Architected for durability and reliability

Designed to perform consistently under normal operating conditions, the Square D 992140 combines precise electrical characteristics with robust construction. This makes it a practical, long-lasting choice for maintaining safe, controlled power in 120V applications where a dedicated branch circuit requires up to 40 amps of protection.