Square D QOB-3301021 QO Series...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$642.14
Square D QOB-3301021 QO Series 3-Pole Bolt-On Circuit Breaker with AC Shunt Trip

Square D QOB-3301021 QO Series 3-Pole Bolt-On Circuit Breaker with AC Shunt Trip

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Model: QOB3601021

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

$642.14
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Square D QOB-3301021 QO Series 3-Pole Bolt-On Circuit Breaker with AC Shunt Trip

The Square D QOB-3301021 QO Series 3-Pole Bolt-On Circuit Breaker with AC Shunt Trip delivers thermal magnetic overcurrent protection and switching for ac and dc systems. Rated 120/240VAC with a 22kA interrupt rating, this bolt-on breaker is available across a Motor FLA range from 30A to 60A and uses an over-center, trip-free toggle mechanism with quick-make, quick-break action for dependable performance. UL Listed and CSA certified, it accepts AWG 8...AWG 2 copper or aluminium conductors and is HACR rated, making it suitable for commercial and industrial panelboard installations that require remote shunt-trip switching.

Key Features

  • Configuration: 3-pole, bolt-on circuit breaker requiring 4 panelboard spaces.
  • Electrical Rating: 120/240VAC operational voltage with a 22kA interrupt rating for demanding overcurrent protection.
  • Motor FLA Range: Available in Motor FLA ratings from 30A to 60A to match application requirements.
  • AC Shunt Trip Accessory: Equipped for shunt trip 120/208/240 V AC remote tripping capability.
  • Wire Range: Accepts AWG 8...AWG 2 copper or aluminium conductors.
  • Trip Mechanism: Over-center, trip-free toggle mechanism with quick-make, quick-break action and positive contact indication.
  • HACR Rated: Suitable for heating, air conditioning, and refrigeration equipment circuits.
  • Ambient Operation: Rated for 40 °C ambient air temperature operation.
  • Series: Part of the Square D QO range of miniature circuit breakers (MCB).

Certifications & Compliance

  • UL Listed
  • CSA
  • RoHS Exemption Information: Yes
  • Halogen Free Product
  • Green Premium Product

Technical Specifications

  • Series: QO
  • Standards: CSA
  • Poles Description: 3P
  • Number Of Spaces Required: 4
  • Range Of Product: QO
  • Warranty Period: 18 months
  • Mercury Free: Yes
  • Toxic Heavy Metal Free: Yes

Typical Applications

  • Commercial and Industrial Panelboard Circuit Protection
  • AC and DC Overcurrent Protection Systems
  • HACR Equipment Circuits
  • Remote Shunt-Trip Switching Applications
  • Renovation and New Construction Electrical Panels

Why Square D?

Square D QO circuit breakers combine a trip-free toggle mechanism with quick-make, quick-break action for dependable, code-compliant overcurrent protection. UL Listed and CSA certified, with Green Premium and halogen-free construction, this bolt-on breaker with AC shunt trip capability is built for reliable performance across its full Motor FLA range in commercial and industrial electrical panels.

Manufacturer Resources

Product Specs

Product Type:
Circuit Breaker
Series:
QO
Configuration:
3-Pole
Voltage Rating:
120/240VAC
Connection Type:
Bolt-On
Listing:
UL Listed
Standards:
CSA
Department:
Electrical
Product Group:
Wiring Devices
Amperage Rating:
30A - 60A
Product Subgroup:
Circuit Breakers

Square D QOB3601021 – Frequently Asked Questions

1) Will a Square D QOB bolt-on breaker fit my plug-on QO load center?
No. The QO 3-pole shunt trip breaker is a bolt-on (QOB) design, so it mounts to a panelboard interior with mounting hardware rather than snapping onto plug-on bus stabs. It needs a panelboard built for QOB bolt-on breakers. If your interior takes plug-on QO breakers, this one will not mount.
2) How many panelboard spaces does the 3-pole QO shunt trip breaker take up?
Four spaces, not three. The shunt trip accessory sits alongside the three poles and adds a space, so plan the panel schedule for 4 poles' worth of room before you order.
3) What size wire can I land on a Square D QOB 3-pole shunt trip breaker?
The lugs accept AWG 8 through AWG 2, copper or aluminum. Anything larger than 2 AWG will not terminate, so if your feeder calculation pushes past that you need a different frame.
4) What voltage do I feed the shunt trip coil on this QO breaker?
The shunt trip is an AC coil rated for 120/208/240 V AC remote tripping. Run your trip signal from a fire alarm relay, elevator recall contact or emergency stop at one of those voltages. The breaker itself is rated 120/240VAC.
5) Can I use an ABB ST200M miniature circuit breaker instead of a Square D QOB breaker for a motor branch circuit?
They are not interchangeable for this duty. The ABB ST is an ST200M miniature circuit breaker built to UL1077, which is a supplementary protector standard rather than a branch circuit breaker standard. The Square D QOB 3-pole bolt-on breaker is UL Listed and CSA certified for panelboard branch circuit overcurrent protection, is HACR rated for heating, air conditioning and refrigeration equipment, and accepts AWG 8 to AWG 2 copper or aluminium conductors. For a motor or HACR branch circuit in a QO panelboard, specify the QOB.
6) Is the ABB A2N 3-pole molded case breaker a drop-in replacement for a Square D QOB 3-pole bolt-on shunt trip breaker?
No. The Square D QOB 3-pole breaker is a bolt-on device built for QO panelboard interiors, rated 120/240VAC, and it carries an AC shunt trip for remote tripping. The ABB A2A150TT is an A2 Series 3-pole molded case circuit breaker, a different mounting and frame family that mounts to its own enclosure or panel provisions. If the existing panel is a QO interior with bolt-on mounting pads, stay with the QOB; the molded case ABB would require its own enclosure or adapter arrangement.
7) Can I use this breaker on a rooftop unit or air conditioning circuit?
Yes, it is HACR rated, so it is suitable for heating, air conditioning and refrigeration equipment circuits. Pair the amp rating to the nameplate maximum overcurrent protection on the unit; the choices are 30A, 50A and 60A.
8) Is this Square D breaker UL Listed and CSA certified for a commercial job?
Both. The QO bolt-on shunt trip breaker is UL Listed and carries CSA certification, which is what most commercial and institutional specs call for in a panelboard branch or feeder device.
9) What are my options if I need a 3-pole breaker but not a QO panelboard?
The Square D QOB is a bolt-on miniature breaker built for QO-style panelboards. If you are working in another manufacturer's gear, ZenSupply carries 3-pole alternatives including the ABB A2N Series molded case breaker (UL Listed), the ABB E150 Series 3-pole thermal magnetic breaker, and the ABB XT4 Series 3-pole molded case kit. Molded case frames mount differently than a QO bolt-on, so match the breaker to the panel or switchboard it is going into.
10) Can this breaker be repaired or have the shunt trip coil replaced in the field?
No. The QO bolt-on shunt trip breaker is listed as non-serviceable, so the shunt trip is not a field-installed or field-replaceable accessory on it. If the coil fails, the whole breaker gets swapped.
11) What is the difference between the Square D QOB 3-pole breaker and the ABB E150 3-pole thermal magnetic breaker?
Both are 3-pole breakers using thermal magnetic overcurrent protection. The Square D QOB is a bolt-on unit for QO panelboards, rated 120/240VAC with a 22kA interrupting rating, HACR rated, and factory equipped with an AC shunt trip for remote tripping from a fire alarm or E-stop circuit. The ABB TEB is an E150 Series 3-pole thermal magnetic circuit breaker in ABB's own frame family. Choose on the panel you are feeding and on whether remote shunt tripping is part of the sequence of operation.
12) I need a 3-pole breaker that ships as a kit with accessories - how does the ABB XT4 kit compare to the Square D QOB shunt trip breaker?
The ABB MBB33 is an XT4 Series 3-pole molded case circuit breaker kit, so it is assembled around ABB's XT4 frame. The Square D QOB 3-pole comes as a complete bolt-on breaker already equipped for shunt trip at 120/208/240 V AC, occupying 4 panelboard spaces, with no separate accessory assembly needed to get remote tripping. If the job is an existing QO panelboard and the only requirement is remote trip, the QOB is the direct answer; the XT4 kit belongs with ABB molded case gear.
13) What ambient temperature is this Square D breaker rated for?
40 degrees C ambient air. That is the standard calibration point, so in a hot mechanical room or an enclosed electrical closet running above that, derating applies to the trip rating.
14) If I do not need remote tripping, what changes between the QOB shunt trip breaker and other 3-pole options?
The shunt trip is the deciding feature. The Square D QOB 3-pole bolt-on breaker is built with an AC shunt trip for remote tripping at 120/208/240 V AC and requires 4 panelboard spaces rather than 3 to house it. Where no remote trip signal is involved, a standard 3-pole molded case unit such as the ABB A2A150TT in the A2 Series or the ABB TEB in the E150 Series covers straight overcurrent protection in ABB gear. Match the breaker family to the panel or enclosure you are installing into.
How fast can I get the Square D QOB3601021 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 QOB3601021 come with a warranty?
Absolutely. The Square D QOB3601021 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 QOB3601021?
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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