Square D QO 40A 2-Pole Bolt-On...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$975.99
Square D QO 40A 2-Pole Bolt-On Circuit Breaker with Class B Ground Fault Protection

Square D QO 40A 2-Pole Bolt-On Circuit Breaker with Class B Ground Fault Protection

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Model: QOB240EPD

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

$975.99
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Square D QO 40A 2-Pole Bolt-On Circuit Breaker with Class B Ground Fault Protection

The Square D QO 40A 2-Pole Bolt-On Circuit Breaker with Class B Ground Fault Protection is a thermal magnetic circuit breaker built on the trusted QO/QOB platform for overcurrent protection and switching on AC and DC systems. Rated 120/240VAC with a 10kA interrupt rating, this bolt-on breaker delivers 30mA Class B ground fault protection for added personnel safety, and features an over-center, trip-free toggle mechanism with quick-make, quick-break action and positive trip indication. UL Listed and CSA certified, it is engineered for reliable, code-compliant performance in panelboard applications.

Key Features

  • Amperage & Poles: 40A, 2-pole configuration for balanced circuit and load protection.
  • Voltage Rating: 120/240VAC operation for standard panelboard circuits.
  • Mounting Type: Bolt-on mounting for a secure, vibration-resistant connection in the panelboard.
  • Ground Fault Protection: Class B 30mA ground fault protection for enhanced circuit and personnel safety.
  • Interrupt Rating: 10kA short-circuit current rating for dependable fault interruption.
  • Trip Mechanism: Over-center, trip-free toggle with quick-make, quick-break action and positive trip operation.
  • Wire Range: Accepts AWG 12…AWG 4 aluminum or AWG 14…AWG 6 copper conductors.
  • Tightening Torque: 4.6 N.m (AWG 12…AWG 4) and 5 N.m per manufacturer specification.

Certifications & Compliance

  • UL Listed
  • CSA Certified
  • TAA Compliant
  • RoHS EU Compliant with Exemptions

Technical Specifications

  • Warranty: 18 months
  • Warranty Period: 18 months
  • Sustainable Packaging: No
  • Mercury Free: Yes
  • Number Of Spaces Required: 2
  • Packaging Without Single Use Plastic: Yes
  • Tier Id: 1
  • ROHS Eur In Scope: Yes
  • Recycled Metal Content At Cr Level: 0 %
  • H And D Enrichment Function: EPD
  • Poles Description: 2P
  • H And D Enrichment Assignment: yes
  • Serviceability: No
  • With Recycled Cardboard: No
  • WEEE Product Category: 5
  • Range Of Product: QO
  • Compliance: TAA
  • China ROHS In Scope: No
  • Return Indicator: Y
  • Take Back: No
  • Tier: 1
  • Returnability: Yes
  • Field Service Division: PPIBS
  • Market Segmentation: Commercial
  • H And D Subrange: COM
  • WD Status: 1 - GSC certified
  • Green Premium Status For Reporting: Green Premium product
  • Country of Origin: Mexico
  • Legacy WEEE Scope: In

Typical Applications

  • Residential and Commercial Panelboards
  • Load Center Circuit Protection
  • Ground Fault Protected Branch Circuits
  • Renovation and New Construction Electrical Panels
  • OEM Panel Assembly and Equipment Manufacturing

Why Square D?

Square D QO circuit breakers are built with an over-center, trip-free toggle mechanism and quick-make, quick-break action for dependable, code-compliant circuit protection. Backed by an 18-month warranty and UL Listed, CSA certified construction, this bolt-on QO breaker with integrated Class B ground fault protection is engineered for the reliability electrical professionals expect from Square D.

Manufacturer Resources

Product Specs

Product Type:
GFCI/AFCI Circuit Breaker
Series:
QO
Amperage Rating:
40A
Voltage Rating:
120/240 VAC
Connection Type:
Bolt-On
Configuration:
2-Pole
Listing:
UL Listed
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Circuit Breakers
Product Height:
4.13 in
Product Width:
1.5 in
Product Depth:
2.91 in

Square D QOB240EPD – Frequently Asked Questions

1) Will a Square D QOB240EPD breaker fit a plug-in QO load center?
No. The QOB240EPD is a bolt-on breaker, so it mounts with screws to the panel bus and needs a panelboard with bolt-on provisions. A QO plug-in load center will not accept it. If your panel takes plug-in QO breakers, you need the plug-on version of the same 40A 2-pole rating instead.
2) Is 30mA Class B ground fault protection the same as a GFCI receptacle breaker?
No, and this is the most common mistake on this part. The QOB240EPD provides 30mA Class B ground fault protection, which is equipment protection, not the 5mA Class A personnel protection required for GFCI-protected receptacle branch circuits. Use it where equipment ground fault protection is specified (feeders to equipment, heat trace, some motor loads). If the drawing calls for Class A GFCI, look at a Class A device such as the Eaton CH Series Class A GFCI breaker with pigtail.
3) What wire size can I land on the Square D QOB240EPD 40A breaker?
Lug range is AWG 12 to AWG 4 aluminum or AWG 14 to AWG 6 copper. For a 40A load on copper you would normally be pulling 8 AWG, which is comfortably inside that range. Torque the lugs to 4.6 N.m for AWG 12 to AWG 4.
4) Can this QOB breaker be used on a 240V single-phase circuit at 10kA available fault current?
Yes. The breaker is rated 120/240 VAC with a 10kA interrupting rating, so a 2-pole 240V single-phase branch circuit on a panel with up to 10kA available fault current is within rating. Above 10kA you need a higher AIC device or series-rated combination.
5) What are my options if I need a ground fault breaker but my panel is GE or ABB rather than Square D?
The QOB platform only fits Square D bolt-on panelboards. For an ABB/GE-style panel, the ABB THQB 2-pole GFT breaker is the comparable 10kA 240V ground fault type, and the ABB THQL plug-on neutral ground fault breaker covers plug-on neutral loadcenters. Breaker bus interfaces are not interchangeable between manufacturers, so match the panel brand.
6) If the circuit also needs arc fault protection, what should be used instead of the Square D QOB240EPD?
The Square D QOB240EPD provides thermal magnetic overcurrent protection plus 30mA Class B ground fault protection, with no arc fault function. Where both arc fault and ground fault protection are required on the same circuit, a dual function device is needed, such as the ABB Q-Line THQL11 DFCI Dual Function AFCI/GFCI Circuit Breaker. Confirm the panel accepts the THQL11 series before specifying it.
7) What 2-pole ground fault breaker can be used in place of the Square D QOB240EPD in a non-Square D panel?
The Square D QOB240EPD is a 40A 2-pole bolt-on breaker rated 120/240 VAC with 30mA Class B ground fault protection, and it only mounts in panelboards that accept the QO/QOB bolt-on interior. For an ABB panel, the closest 2-pole ground fault equivalent is the ABB THQB 2-Pole GFT Circuit Breaker, rated 10kA at 240V. Breakers are not interchangeable across manufacturers, so the panel label has to list the breaker series as acceptable before either one goes in.
8) Does the Square D QOB240EPD protect people like a GFCI receptacle breaker does?
No. The Square D QOB240EPD carries 30mA Class B ground fault protection, which is an equipment-protection trip level, not the 5mA personnel level required for GFCI-protected branch circuits. If the circuit needs personnel GFCI protection, a Class A device is the correct choice, such as the Eaton CH Series Class A GFCI Circuit Breaker with Pigtail or the ABB THQL Q-Line Model 3 Self-Test GFCI Circuit Breaker. Those are different protection classes and are not substitutes for one another.
9) How many panel spaces does the 40A 2-pole QOB breaker take up?
Two spaces. It is a 2-pole breaker at 1.5 inches wide overall, and Square D lists it as requiring 2 spaces in the panelboard. Overall body size is 4.13 x 2.91 x 1.5 inches, which matters if you are checking gutter depth on a shallow enclosure.
10) Does the Square D QOB240EPD carry a UL listing for use in a commercial panelboard?
It is UL Listed and CSA certified, and Square D segments it as a commercial product for panelboard and load center use. It is also TAA compliant, which matters on federally funded work, and RoHS EU compliant with exemptions. Country of origin is Mexico.
11) What is the difference between the bolt-on Square D QOB240EPD and a plug-on ground fault breaker?
The Square D QOB240EPD uses a bolt-on connection, which fastens to the panelboard bus for a secure, vibration-resistant termination and is typical of panelboard interiors. A plug-on device such as the ABB THQL Series Plug-On Neutral Ground Fault Circuit Breaker, rated 10kAIC, snaps onto the bus instead and is used in load centers built for plug-on neutral. The mounting style is set by the panel interior, so it is not a field choice.
12) Is the ABB THQB GFT breaker a direct swap for a Square D QOB240EPD?
It is a comparable device, not a direct swap. Both are 2-pole ground fault breakers rated at 240V with a 10kA interrupting capacity, but the QOB240EPD is built on the Square D QO/QOB bolt-on platform while the ABB THQB 2-Pole GFT breaker belongs to ABB's THQB series. Each only fits panels listed for its own series, so the swap depends entirely on which panelboard is in the field.
13) How do I tell whether the Square D QOB breaker has tripped versus just being switched off?
The toggle gives positive trip indication. It uses an over-center, trip-free mechanism with quick-make, quick-break action, so the handle moves to a distinct tripped position and the breaker cannot be held closed on a fault. Reset by pushing the handle fully off, then back on.
14) Which ground fault breaker has a built-in self-test feature if the Square D QOB240EPD does not?
The Square D QOB240EPD uses an over-center, trip-free toggle with quick-make, quick-break action and positive trip indication for its 30mA Class B ground fault function. Where a self-testing GFCI device is wanted, the ABB THQL Q-Line Model 3 Self-Test GFCI Circuit Breaker covers that requirement. Note it is a Class A GFCI device rather than a Class B equipment ground fault breaker, so the protection level differs as well.
How fast can I get the Square D QOB240EPD 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 QOB240EPD come with a warranty?
Absolutely. The Square D QOB240EPD 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 QOB240EPD?
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
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