Square D QHB320 - 20 A, 3-Pole Bolt-On Circuit Breaker | AmpState

The Square D QHB320 delivers reliable protection for branch circuits in panelboards and loadcenters with a compact, rugged design that technicians trust. Engineered as a 20A, 3-pole bolt-on molded case circuit breaker, it combines precise protection with straightforward installation, making it a smart choice for residential upgrades, commercial panel additions, or light industrial control panels.

Why the Square D QHB320 Stands Out

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, helping maintain consistent electrical contact in installations where equipment experiences movement or vibration.
• Thermal-magnetic trip unit delivers stable, repeatable protection by responding to both overcurrent conditions and short circuits, reducing nuisance trips and safeguarding downstream components.
• OEM-ready compatibility is designed to work with matching Square D load centers and panelboards, simplifying replacements and upgrades without compromising fit or performance.
• Versatile application suitable for residential panels, commercial distribution, and light industrial applications where dependable circuit protection is essential.

Key Features and Benefits

• Amperage rating: 20A tailoring protection for individual branch circuits without over-restraining performance.
• Number of poles: 3 ideal for three-phase or multi-circuit configurations common in modern panels.
• Mounting style: Bolt-on ensures a solid connection and simplifies field installation or retrofits in existing enclosures.
• Type: Thermal-magnetic molded case circuit breaker combines precise thermal (overload) protection with rapid magnetic (short-circuit) response.
• Manufacturer/Part Square D, QHB320 — a trusted solution from a recognized name in electrical protection.

Ideal Applications

Use the QHB320 when you need dependable branch circuit protection in:

• Residential main or subpanel upgrades where a reliable 20A, 3-pole breaker is needed.
• Commercial load centers powering lighting, outlets, or small equipment circuits.
• Light industrial panels requiring robust protection with a secure bolt-on installation.

Practical Guidance and Use Cases

• When upgrading or adding circuits, pair the QHB320 with matching OEM load centers to ensure optimal fit, performance, and compatibility with existing bus connections.
• For installations in environments with periodic vibration (pumps, HVAC equipment, machinery), the bolt-on design helps maintain a stable electrical connection over time.
• In retrofit projects, verify that the panelboard supports 3-pole breakers of this type and that wire sizing and overcurrent protection align with local electrical codes.

Specifications at a Glance

• Manufacturer: Square D
• Part Number: QHB320
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 20A
• Number of Poles: 3
• Mounting Style: Bolt-on
• Applications: Branch circuit overcurrent and short-circuit protection