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Square D QOB-GFI QO 2-Pole Bolt-On Circuit Breaker, Ground Fault Class A
Model: SQU-QOB-GFI
Square D QOB-GFI QO 2-Pole Bolt-On Circuit Breaker, Ground Fault Class AThe Square D QO 2-Pole Bolt-On Circuit Breaker (QOB-GFI) delivers thermal magnetic overcurrent protection for ac and dc...
Square D
Starting at
$591.51
Square D QO Mercury-Free Mechanical Interlock Circuit Breaker Accessory, 1-2 Pole
The Square D QO Mechanical Interlock is a circuit breaker accessory engineered for compatibility with QO and QOB one and two pole thermal magnetic circuit breakers. These breakers feature an over-center, trip-free toggle mechanism with quick-make, quick-break action for reliable overcurrent protection and switching on ac and dc systems. Built with mercury-free, toxic-heavy-metal-free, and halogen-free construction, this interlock secures equipment so contact points remain energy-efficient, supporting safe, code-compliant panelboard assemblies in residential installations.
Key Features
- Compatibility: Mechanical interlock accessory compatible with 1 to 2 pole QO and QOB circuit breakers.
- Secure Mounting: Secures equipment so that contact points are energy-efficient.
- Engineered Quality: QO™ MCBs are engineered for quality and reliability.
- Material Safety: Mercury free and toxic heavy metal free construction.
- Low-Impact Materials: Halogen free product for reduced environmental impact.
- Warranty Coverage: Backed by an 18 month manufacturer warranty.
Certifications & Compliance
- RoHS EUR Full Compliance Status: Compliant
- RoHS EUR In Scope
- Mercury Free
- Toxic Heavy Metal Free
- Halogen Free Product
- Prop 65 Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Technical Specifications
- Series: QO
- Warranty: 18 months
- Mercury Free: Yes
- Toxic Heavy Metal Free: Yes
- Halogen Free: Yes
Typical Applications
- Residential Electrical Panelboards
- QO and QOB Load Center Circuit Breaker Installations
- Contractor and OEM Electrical Assemblies
- Renovation and New Construction Wiring Projects
Why Square D?
Square D QO mechanical interlock accessories are engineered for quality and reliability, helping secure equipment so contact points stay energy-efficient in residential electrical systems. With mercury free, toxic heavy metal free, and halogen free construction plus RoHS EUR compliance and an 18 month warranty, this accessory supports safe, code-compliant panelboard assemblies for contractors and electricians working with the QO and QOB breaker line.
Manufacturer Resources
Product Specs
- Product Type:
- Circuit Breaker Accessory
- Series:
- QO
- Configuration:
- 1-2 Pole
- Standards:
- RoHS EUR Compliant
- Department:
- Electrical
- Product Group:
- Circuit Protection
- Product Subgroup:
- Circuit Breakers
- Country Of Origin:
- United States
Square D QO2DTI – Frequently Asked Questions
1) What does the Square D QO2DTI mechanical interlock actually do in a panel?
The QO2DTI is a mechanical interlock kit, not a breaker. It mounts over a pair of adjacent QO or QOB breakers so only one of the two can be switched on at a time. That is the standard way to keep a utility main and a generator or alternate source from ever being closed together in the same load center. You supply the breakers; the interlock is the hardware that enforces the lockout mechanically.
2) Will the QO2DTI interlock fit my QO load center breakers?
It is made for QO and QOB thermal magnetic breakers in one and two pole configurations. If the breakers you want to interlock are single pole or two pole QO or QOB, this is the right accessory. Three pole breakers, or any other breaker line (Homeline, BR, QP), are outside what this interlock is built for.
3) I have Eaton breakers, not Square D. Can I use this interlock?
No. The QO2DTI is built around QO and QOB breaker geometry and will not work on another manufacturer's line. For Eaton equipment you need Eaton's own accessories, and the Eaton accessory hardware is series-specific too: the Series G multiwire connector kit, the Series C rotary lower mechanism handle accessory, and the FAZ bus bar terminal cover each fit only their stated frame. Match the accessory to the breaker series you actually have in the panel.
4) Can an Eaton Series C rotary handle mechanism be used in place of the Square D QO2DTI mechanical interlock?
No. The QO2DTI is a mechanical interlock built for one and two pole QO and QOB thermal magnetic breakers, so it is tied to the QO breaker line. The Eaton 6648C23G19 is a rotary lower mechanism handle accessory for Eaton Series C breakers, a different manufacturer's frame and a handle-operator part rather than an interlock between two breakers. Match the accessory to the breaker family already in the panel.
5) Do I order one interlock per breaker or one per pair?
One QO2DTI kit covers the interlocked set. The accessory is sold as the single model QO2DTI and is rated for the 1 to 2 pole QO/QOB range, so you buy one kit for the breaker pair you are interlocking, plus the breakers themselves, which are not included.
6) What kind of installations is this QO interlock intended for?
Residential panelboards and QO/QOB load center installations, which is where most generator interlock work happens. Contractors and OEMs also use it in assembled panel builds and in renovation or new construction wiring. It is not a large-frame accessory; for multi-pole sub-feed work on industrial frames you would be looking at something like the ABB XT4 Pro-Stak 6-pole sub-feed kit instead.
7) I need a sub-feed arrangement on a larger breaker frame, not a QO panel. What should I look at instead of the QO2DTI?
The QO2DTI is a QO series accessory for one and two pole QO and QOB breakers in residential panelboards. For a sub-feed arrangement on a larger molded case frame, the ABB MBB36 is a Pro-Stak six pole sub-feed circuit breaker accessory kit for the ABB XT4 series. It serves a sub-feed function on an ABB frame rather than interlocking two QO breakers.
8) What is the difference between the Square D QO2DTI and the Eaton FAZ bus bar terminal cover?
They solve different problems. The QO2DTI is a mechanical interlock that ties one and two pole QO or QOB breaker handles together so only one source can be closed at a time. The Eaton ZV-BS-UL is a bus bar terminal cover for FAZ miniature circuit breakers, a shrouding part for exposed terminals. A panel needing both handle interlocking and terminal shielding needs two separate accessories.
9) Will the Eaton multiwire connector kit work with QO breakers the way the QO2DTI does?
No. The Eaton 3TA is a multiwire connector kit for EG-Frame Series G breakers, rated 125A three-wire for #14-2 AWG conductors, so it is a wire termination accessory on an Eaton frame. The Square D QO2DTI is a mechanical interlock for one and two pole QO and QOB breakers. Neither substitutes for the other, and accessories are not interchangeable across the two breaker lines.
10) For a facility standardizing on RoHS-compliant, mercury-free electrical accessories, how does the QO2DTI compare with the other breaker accessories available?
The Square D QO2DTI is stated as RoHS EUR compliant, mercury free, toxic heavy metal free, and halogen free, and is made in the United States. The comparable accessories are identified by their breaker families only: the ABB MBB36 for the XT4 series, the Eaton 3TA for Series G, the Eaton 6648C23G19 for Series C, and the Eaton ZV-BS-UL for FAZ. If the material-content declaration is part of your submittal package, the QO2DTI carries that documentation.
11) Is this Square D interlock RoHS compliant and free of restricted materials?
RoHS EUR compliant, and built mercury free, toxic heavy metal free, and halogen free. For agencies and institutional buyers running green procurement specs, those are the material claims Square D publishes on the QO interlock. Note that it also carries a California Prop 65 warning for cancer and reproductive harm.
12) Where is the Square D QO2DTI interlock made?
Made in the United States. That matters if you are buying against a Buy American or domestic-preference clause on a public or institutional job, where accessory kits get scrutinized alongside the breakers.
How fast can I get the Square D QO2DTI delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
continental
U.S.
Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit,
reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Square D QO2DTI come with a warranty?
Absolutely. The Square D QO2DTI is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Square D QO2DTI?
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