Square D QOB21251021 - 125 A, 2-Pole Bolt-On Circuit Breaker | AmpState

Meet the Square D QOB21251021 — a 125A, 2-pole bolt-on molded case circuit breaker engineered to safeguard panelboards and load centers from overcurrent and short circuits.

Designed for durable operation in residential, commercial, and light industrial environments, this breaker offers a secure bolt-on mounting that creates a rigid, vibration-resistant bus connection, reducing movement and loosening over time. The thermal-magnetic trip unit delivers stable, repeatable protection performance, opening the circuit quickly on faults while minimizing nuisance trips during normal load fluctuations.

Key features

• 125A, 2-pole bolt-on design provides dedicated protection for a wide range of circuits with straightforward replacement in compatible panels.
• Bolt-on mounting ensures a solid, vibration-resistant connection to bus bars for long-term reliability.
• Thermal-magnetic trip unit blends thermal protection for overload with magnetic trip for instantaneous short-circuit response.
• OEM compatibility with matching Square D load centers and panelboards for seamless integration.
• Versatile applications ideal for residential service panels, commercial equipment rooms, and light industrial installations needing dependable branch-circuit protection.

Who benefits from the QOB21251021?

• Electricians upgrading or expanding panelboards and load centers who require a reliable 125A, 2-pole bolt-on breaker.
• Homeowners or facility managers performing subpanel installs or circuit protection upgrades where a robust, consistent trip characteristic matters.
• Maintenance teams that value vibration resistance and stable performance under varying loads.

Technical snapshot

• Part number: QOB21251021
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 125 A
• Number of poles: 2
• Mounting style: Bolt-on
• Applications: Branch circuit overcurrent and short-circuit protection