Siemens B345H - 45 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens B345H 45A, 240V, 3-Pole Bolt-On Circuit Breaker

Designed for dependable branch circuit protection, the Siemens B345H is a 45A, 240V, 3-pole molded case circuit breaker built to fit bolt-on panelboards and loadcenters. This unit delivers precise, reliable overcurrent and short-circuit protection where it’s most needed, keeping equipment safer and systems running smoothly.

• Bolt-on mounting for a rigid, vibration-resistant connection — ensures a secure bus connection that stays tight through equipment vibration and operation, reducing loosened contacts over time.
• Thermal-magnetic trip unit for stable protection — combines thermal overload protection with magnetic short-circuit protection, delivering fast, repeatable trips at the correct current to safeguard downstream circuits.
• OEM-compatible for seamless integration — engineered to be compatible with matching Siemens OEM load centers and panelboards, facilitating straightforward installation and reliable performance.
• Versatile for multiple settings — suited for residential, commercial, and light industrial applications where robust 3-phase protection is required.

Technical snapshot

• Manufacturer: Siemens
• Part Number: B345H
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 45A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

The B345H is a practical choice when upgrading or extending power distribution in panelboards and loadcenters that support bolt-on breakers. It provides predictable, maintainable protection for three-phase circuits, making it ideal for equipment like HVAC systems, motors, pumps, lighting, and other common commercial and light industrial loads.

What makes this breaker stand out is its combination of secure installation, reliable trip performance, and seamless OEM compatibility. When you need a dependable 3-pole solution that fits cleanly into Siemens-compatible panels, the B345H delivers a straightforward path to safer, more resilient electrical distribution.

Installation tips: ensure your panelboard accepts bolt-on breakers and follow standard torque specifications for the mounting screws to maintain a solid bus connection. Regularly inspect connections for signs of wear or arcing, and reset or test the trip unit per your maintenance practices to keep protection in peak condition.