Square D QO Series Circuit Bre...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$11.36
Square D QO Series Circuit Breaker Handle Lock-Off Padlock Attachment

Square D QO Series Circuit Breaker Handle Lock-Off Padlock Attachment

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Model: HLO1

In Stock (leaves warehouse same day if ordered before 3pm ET)

$11.36
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Square D QO Series Circuit Breaker Handle Lock-Off Padlock Attachment

The Square D QO Series Circuit Breaker Handle Lock-Off Padlock Attachment secures the handle of a Square D QO thermal magnetic circuit breaker in the off position, supporting proper lockout/tagout procedure for electricians and facility maintenance teams. It is designed for use across the QO and QOB one, two, and three pole breaker line, which provides overcurrent protection and switching on ac and dc systems with an over-center, trip-free toggle mechanism and quick-make, quick-break action. The accessory is TAA compliant, making it suitable for government and federal procurement requirements, and is built for use in residential and light commercial electrical systems.

Key Features

  • QO Series Compatibility: Engineered for the QO range of Square D thermal magnetic circuit breakers, sized to fit the corresponding pole configuration on QO and QOB breakers.
  • Handle Lock-Off: Accepts a standard padlock to lock the breaker handle in the off position for safe lockout/tagout during service or maintenance work.
  • Trip-Free Toggle Compatibility: Supports QO and QOB breakers featuring an over-center, trip-free toggle mechanism with quick-make, quick-break action for reliable switching.
  • TAA Compliant: Meets Trade Agreements Act requirements, supporting use on federally funded electrical projects and government procurement.
  • Mercury Free Construction: Manufactured without mercury for safer handling and disposal throughout its service life.
  • Halogen-Free Material: Constructed from a halogen-free product formulation for reduced environmental impact.

Certifications & Compliance

  • TAA Compliant
  • RoHS EUR Compliant with Exemptions
  • Mercury Free
  • Halogen-Free Product

Technical Specifications

  • Product Type: Circuit Breaker Accessory
  • Series: QO

Typical Applications

  • Residential Load Centers and Panelboards
  • QO Circuit Breaker Lockout/Tagout Safety Procedures
  • Electrical Panel Maintenance and Service
  • Commercial and Residential Electrical Installations

Why Square D?

Square D QO circuit breaker accessories are built to complement the performance and durability of the QO line, giving electricians and facility managers a reliable way to lock out breaker handles during maintenance. With TAA compliance, mercury-free, and halogen-free construction, this padlock attachment supports code-conscious, safety-focused electrical work across residential and commercial installations where lockout/tagout compliance is required.

Manufacturer Resources

Product Specs

Product Type:
Breaker Lockout Device
Series:
QO
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Circuit Breakers

Square D HLO1 – Frequently Asked Questions

1) Does the Square D QO lock-off hold the breaker in the off position only, or can it lock it on?
It locks the breaker handle in the OFF position. That is the lockout/tagout direction electricians and maintenance crews need when servicing a circuit, and it accepts a standard padlock to hold it there.
2) What is the difference between a padlocking breaker handle lock and a non-padlocking one?
Two different jobs. The Square D HLO1 is a padlocking attachment: it takes a padlock so the breaker cannot be turned back on until the lock is removed, which is what a formal lockout/tagout program requires. A non-padlocking handle lock, like the ABB THQP series snap-on handle lock, instead restrains the handle to stop accidental switching, with no provision for a padlock. If your work needs verifiable LOTO, use the padlocking type.
3) Can the ABB THQP handle lock be used on a Square D QO breaker instead of the HLO1?
No. The ABB device is built for the THQP breaker series and the Square D HLO1 is sized to the QO and QOB handle and pole configuration. Breaker handle accessories are series-specific, so a THQP lock should stay on THQP breakers and QO panels should get the QO lock-off.
4) What is the difference between the Square D HLO1 handle lock-off and the ABB THQP snap-on handle lock?
The Square D HLO1 is a padlock attachment: it holds the handle of a Square D QO or QOB thermal magnetic breaker in the off position and accepts a standard padlock, so it supports a keyed lockout/tagout program. The ABB THQP series handle lock is a snap-on non-padlocking design for THQP breakers, meaning it restrains the handle without providing a padlock shackle point. If your written LOTO procedure requires a personal lock on the device, the padlocking style is the one that satisfies it.
5) Is a padlock included with the Square D HLO1 breaker lock-off?
No padlock comes with it. The HLO1 is the handle attachment itself and accepts a standard padlock, which you supply with your own LOTO kit so each worker can apply their own lock.
6) Is the Square D QO padlock lock-off acceptable for a federally funded job?
Yes, it is TAA compliant, which is what government and federal procurement typically requires. It is also RoHS EUR compliant with exemptions, mercury free, and built from a halogen-free formulation if your spec sheet asks about material content.
7) We standardize our lockout hardware across a facility. Does one HLO1 cover every QO breaker we have?
The attachment is sized to the corresponding pole configuration on QO and QOB breakers, so single, two, and three pole breakers in your panels are covered by the QO lock-off line, but you match the part to the pole count rather than using one piece for all of them. Count your single, double, and triple pole breakers before ordering quantities.
8) If I only need to stop someone from flipping a breaker back on, is a non-padlocking lock enough?
For casual handle restraint on an ABB THQP breaker, the THQP snap-on non-padlocking handle lock covers that job without any padlock to buy or manage. For a Square D QO or QOB breaker being serviced under a lockout/tagout procedure, the HLO1 accepts a standard padlock so the breaker handle stays off under the technician's own lock during panel maintenance.
9) For a federally funded project, which breaker handle lock should I specify?
The Square D HLO1 QO handle lock-off is TAA compliant, which supports government and federally funded procurement, and it is also mercury free and built from a halogen-free formulation. Specify it where the panel uses Square D QO or QOB breakers; a THQP-series lock such as the ABB unit would only apply to THQP breakers.
10) Will the QO lock-off work on breakers in a residential load center as well as a commercial panelboard?
Yes. The QO handle lock-off is used on residential load centers and panelboards and in light commercial electrical systems, anywhere QO or QOB breakers are installed and panel maintenance calls for locking a circuit off.
How fast can I get the Square D HLO1 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 HLO1 come with a warranty?
Absolutely. The Square D HLO1 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 HLO1?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Square D HLO1 from ZenSupply?
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