Siemens Q345 - 45 A, 240 V, 3-Pole Plug-In Circuit Breaker | AmpState

Meet the Siemens Q345 — a 45A, 240V, 3-pole plug-in molded case circuit breaker built to protect your branch circuits with reliability and speed. Designed for quick installation and straightforward replacements, it fits seamlessly into panelboards and load centers.

What it is and where it fits

The Q345 is a thermal-magnetic molded case circuit breaker that provides overcurrent and short-circuit protection for residential, commercial, and light industrial applications. Its plug-in design simplifies panel maintenance and upgrades, letting you swap breakers without invasive wiring work.

Key features

• Plug-in connection for fast installation and replacement—minimizing panel downtime.
• Thermal-magnetic trip unit delivers stable, repeatable protection against both overloads and short circuits.
• 3-pole, 45A, 240V configuration suitable for 3-phase circuits common in light commercial settings.
• Compatible with matching OEM load centers and panelboards to ensure proper fit and trip coordination.
• Versatile applications for residential, commercial, and light industrial electrical systems.

Technical specifications

• Manufacturer: Siemens
• Part Number: Q345
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 45A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection

Practical use cases

• Upgrade or add 3-phase branch circuits in light commercial panels and small industrial control rooms.
• Replace aging breakers in a residential load center when upgrading a subpanel or expanding service to support new equipment.
• Provide dependable protection for motors, HVAC controllers, and other 3-phase equipment in compact installations.

Why this matters

The Siemens Q345 45A, 240V 3-pole plug-in breaker combines a fast, tool-free installation with a robust thermal-magnetic trip that protects your wiring and devices without nuisance trips. Its OEM-load-center compatibility means you won’t fight fit or coordination when integrating with existing systems. If you’re an electrician, facility manager, or a do-it-yourselfer tackling a panel upgrade, this breaker is engineered to deliver reliable protection with predictable performance when it counts.

Installation notes

Installers should follow local electrical codes and use a licensed electrician for safety. Ensure the replacement breaker matches the panel’s rating and trip characteristics for proper coordination and label the panel accordingly.