Siemens HED42B040 - 40 A, 480 V, 2-Pole Bolt-On Circuit Breaker | AmpState

Siemens HED42B040 is a 40A, 480V, 2-pole bolt-on molded case circuit breaker designed for dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Built to deliver consistent protection when it matters, this unit helps keep electrical systems safe and uninterrupted.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection. This design minimizes loosening and ensures reliable electrical continuity in installations subject to vibration or movement.
• Thermal-magnetic trip unit delivers stable, repeatable protection performance. The thermal element handles overload conditions with predictable timing, while the magnetic element delivers instantaneous action during high-energy short circuits, helping to quickly clear faults.
• OEM-compatible design is built to pair with matching Siemens load centers and panelboards, simplifying selection and installation when upgrading or expanding protection in existing systems.
• Versatile application suitable for residential, commercial, and light industrial environments, where reliable branch-circuit protection is essential for safety and uptime.

Overview: what this breaker does for your electrical system

As a bolt-on molded case circuit breaker, the HED42B040 is engineered to protect distribution circuits from overcurrent and short-circuit events. Its 2-pole configuration provides synchronized protection across two conductors, making it ideal for circuits that require simultaneous disconnection. By combining a robust mechanical mounting method with a precise thermal-magnetic trip mechanism, this Siemens breaker offers predictable protection characteristics that electricians trust in panel installations and upgrades.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: HED42B040
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 40A
• Voltage rating: 480V
• Number of poles: 2
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Who benefits from the Siemens HED42B040

Anyone upgrading or expanding panelboards and load centers in residential, commercial, or light industrial settings will appreciate the combination of secure mounting, reliable protection, and OEM-compatible integration. It’s particularly well-suited for circuits that require robust protection in environments where vibration or movement could affect connections, and for projects where a predictable trip response is critical for safety and equipment longevity.

Practical tips for installation and use

Pair this 2-pole bolt-on breaker with Siemens-compatible panelboards to ensure optimal fit and performance. When installing, verify the panel’s compatibility with bolt-on molded case breakers and follow electrical code requirements for secure mounting torque and wiring terminations. For future-proofing, consider keeping a compatible spare on hand to minimize downtime in service panels that demand quick, reliable protection on every circuit.