Square D QOU Series Miniature ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$410.06
Square D QOU Series Miniature Circuit Breaker, Thermal Magnetic

Square D QOU Series Miniature Circuit Breaker, Thermal Magnetic

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Model: QOU350

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

$410.06
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Square D QOU Series Miniature Circuit Breaker, Thermal Magnetic

The Square D QOU Series Miniature Circuit Breaker is a unit mount, cable-in/cable-out thermal magnetic breaker built for OEM applications needing reliable overcurrent protection and switching on AC and DC systems. Available in one, two, or three pole configurations, the QOU Series carries a 10 kA short circuit current rating and supports 120/240 V AC, 120 V AC, and 48 V DC operation. Backed by UL Listed, CSA, and IEC certifications, it delivers dependable performance for OEM electrical distribution equipment.

Key Features

  • Pole Configuration: Available in one, two, or three pole thermal magnetic circuit breaker configurations for OEM overcurrent protection and switching.
  • Wire Range: Accepts AWG 14 through AWG 2 aluminum or copper conductors.
  • Electrical Connection: Slotted box lugs on both the line side and load side for secure cable-in/cable-out termination.
  • Short Circuit Current: 10 kA short circuit current rating for dependable interruption capacity.
  • Operational Voltage: Rated for 120/240 V AC, 120 V AC, and 48 V DC systems.
  • Circuit Breaker Application: HACR rated for heating, air conditioning, and refrigeration equipment circuits.
  • Tightening Torque: 45 lbf.in specified for AWG 14 through AWG 2 terminations.

Certifications & Compliance

  • UL Listed
  • CSA
  • IEC

Technical Specifications

  • Series: QOU
  • Warranty Period: 18 months
  • Toxic Heavy Metal Free: Yes
  • Mercury Free: Yes
  • Serviceability: No

Typical Applications

  • OEM Equipment and Panel Assemblies
  • Commercial and Industrial Electrical Distribution
  • AC and DC Overcurrent Protection Systems
  • Panelboard and Load Center Wiring
  • Renovation and New Construction Projects

Why Square D?

Square D QOU Series circuit breakers are UL Listed, CSA, and IEC certified, HACR rated, and backed by an 18-month warranty, reflecting the build quality professionals expect from OEM electrical distribution equipment. As a mercury free and toxic heavy metal free product, the QOU Series also supports responsible, code-compliant electrical installations across AC and DC overcurrent protection applications.

Manufacturer Resources

Product Specs

Series:
QOU
Product Type:
Circuit Breaker
Listing:
UL Listed
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Circuit Breakers
Product Depth:
2.95 in
Product Height:
4.05 in

Square D QOU350 – Frequently Asked Questions

1) Can a Square D QOU breaker be mounted in a QO load center or panelboard?
No. The QOU Series is a unit mount, cable-in/cable-out breaker, not a plug-on or bolt-on panel breaker. Line and load are both terminated on slotted box lugs, so it mounts as a standalone device inside OEM equipment or an enclosure rather than clipping onto a panel bus. If you need a breaker that lands on a load center bus, a bolt-on type such as the Eaton BAB Series Quicklag thermal-magnetic bolt-on breaker is the kind of device to look at instead.
2) What wire size and torque do the QOU breaker lugs take?
The slotted box lugs accept AWG 14 through AWG 2 in either aluminum or copper, and the specified tightening torque is 45 lbf-in across that whole range. Same termination on the line and load side, so your feeder and load conductors both land in the breaker.
3) Will a Square D QOU breaker work on a 48V DC circuit?
Yes. The QOU Series is rated for 48 V DC as well as 120 V AC and 120/240 V AC, which is why it turns up in DC equipment and telecom-style OEM builds where most residential-style breakers are AC only.
4) Is the QOU breaker rated for an air conditioning or refrigeration circuit?
Yes, the QOU Series is HACR rated, so it can be used on heating, air conditioning, and refrigeration equipment branch circuits. It is UL Listed and also carries CSA and IEC certification.
5) Does the Square D QOU come in two and three pole versions?
Yes. One, two, and three pole thermal magnetic configurations are offered. The pole count is read from the catalog number: QOU120 and QOU125 are single pole, QOU230 is two pole, and QOU350 and QOU360 are three pole.
6) Is 10 kA enough interrupting rating for my panel?
The QOU Series carries a 10 kA short circuit current rating, which covers typical 120/240 V branch and OEM equipment applications. If your available fault current at the point of installation exceeds 10 kA, you need a higher-interrupting molded case breaker instead, such as an ABB A2 Series or XT-frame unit.
7) How much space do I need in the enclosure for a QOU breaker?
Plan on 4.05 in height and 2.95 in depth for the breaker body, plus bending room for AWG 14 to AWG 2 conductors at both lugs since it is cable-in/cable-out on both sides.
8) Is the Square D QOU a UL 1077 supplementary protector or a branch circuit breaker?
The QOU is a UL Listed, HACR rated branch circuit breaker suitable for overcurrent protection and switching. That is a different animal from a UL 1077 supplementary protector such as the ABB ST200M Series C-curve miniature breaker, which is only for protecting devices inside equipment and cannot serve as branch circuit protection.
9) Can I use a QOU breaker on 12V or 24V vehicle wiring?
No. The QOU DC rating is 48 V DC, and it is built for OEM distribution equipment, not vehicle harnesses. For automotive low-voltage work, use a Type I or Type II automotive breaker like the Bussmann CBC Series 14VDC or the Bussmann CBF Series Type II.
10) Can a QOU breaker be repaired or have trip units replaced?
No. The QOU Series is a non-serviceable sealed device, so a tripped-and-failed breaker gets replaced rather than rebuilt. If you need field-changeable ratings, that is a molded case feature, as with the Eaton Series C K-Frame mining breaker and its interchangeable rating plug.
11) Does the QOU breaker meet RoHS-type material restrictions for our spec?
The QOU Series is listed as mercury free and toxic heavy metal free. It is manufactured in Mexico, which is useful if your procurement paperwork requires country of origin.
How fast can I get the Square D QOU350 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 QOU350 come with a warranty?
Absolutely. The Square D QOU350 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 QOU350?
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 QOU350 from ZenSupply?
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