Siemens QJ23B070 - 70 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens QJ23B070 is a 70 A, 240 V, 3-pole bolt-on molded case circuit breaker designed for reliable branch circuit protection in panelboards and loadcenters. Built to endure the demands of real-world electrical environments, it delivers consistent protection where you need it most—within residential, commercial, and light industrial installations.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, reducing movement and ensuring stable electrical continuity in challenging panel environments.
• Thermal-magnetic trip unit combines predictable thermal protection with fast magnetic tripping for short-circuit events, delivering repeatable protection without nuisance trips.
• 3-pole design tailored for three-phase systems common in commercial and light industrial applications, while still suitable for residential panel configurations that require three-phase protection.
• 70 A at 240 V delivers robust overcurrent protection for mid-size branch circuits and equipment feeders, helping manage load demand and prevent damage from faults.
• OEM-compatible with matching Siemens panelboards and loadcenters, enabling straightforward installation and reliable interchanges within existing electrical infrastructure.
• Versatile applications — ideal for new builds, panel upgrades, or service changes in homes, offices, retail spaces, and light industrial facilities.

Why this model fits your system

This QJ23B070 strikes a balance between solid, field-proven protection and practical installation features. The bolt-on mounting is especially advantageous in panels where vibration or movement is a concern, such as equipment rooms or high-traffic electrical spaces. The thermal-magnetic trip unit provides stable, predictable performance across varying temperatures and load conditions, helping to prevent both nuisance trips and undetected faults.

Use cases and scenarios

• Upgrading an aging panel to meet current protection standards in a small business or multi-tenant building.
• Installing a new 3-phase circuit in a commercial office or light industrial space that requires reliable 70 A protection.
• Retrofitting branch circuits in residential settings where three-phase protection is required for certain equipment or HVAC installations.
• Replacing a failed breaker in OEM-compatible Siemens panelboards to maintain electrical system continuity.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: QJ23B070
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 70 A
• Voltage Rating: 240 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Practical notes for installers and facility managers

When integrating the Siemens QJ23B070, plan for a secure bolt-on connection to minimize bus movement and ensure reliable contact under operation. Match it with the corresponding OEM loadcenter or panelboard to preserve electrical clearance and trip coordination. For service updates, verify that the panel’s rating and conductor sizes align with the 70 A, 240 V specification to maintain safe, code-compliant protection.

Choose the Siemens QJ23B070 for a dependable, well-supported solution that delivers clear protective performance, straightforward installation, and compatibility with Siemens panel ecosystems—sound choices for safeguarding circuits in homes, offices, and light industrial settings.