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Square D QOU3100-1021 QOU31001021 - 100A 3 Pole Miniature Circuit Breaker
- 100A
- 3 Pole
- Unit Mount
Square D
QOU3100-1021
QOU31001021 - 100A 3 Pole Miniature Circuit Breaker
Brand
Square D
SKU
QOU3100-1021
Quantity
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Square D QOU31001021 - 100A 3 Pole Miniature Circuit Breaker
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Description
Engineered for industrial applications, this 100-amp miniature breaker includes a factory-installed 120/240VAC shunt trip for remote operation. The mechanism allows external control systems to open the circuit automatically during emergencies. It installs into OEM control panels, enclosures, and standard DIN rail systems using reversible box lugs. Delivering a 10kA interrupting rating at 240VAC, the device features Square D's signature Visi-Trip indicator for rapid fault identification.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOU31001021 |
| Series | QOU |
| Amperage | 100A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 60VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC, 5kA @ 60VDC |
| Frame Type | QOU |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | DIN Rail Systems, OEM Panels, Enclosures, Control Panels |
| Wire Gauge | 12 AWG - 2/0 AWG |
| Max Wire | 2/0 AWG |
| Min Wire | 12 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Mounting Feet, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, UL 489, HACR Rated |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, Common Trip |
Product FAQs
6 answersWhat does the -1021 suffix indicate on the QOU3100-1021?
The -1021 suffix denotes a factory-installed shunt trip accessory. This allows the breaker to be opened remotely via a 120/208/240V AC control signal, which is commonly used for emergency stops or automated shutdown sequences.
How is the QOU3100-1021 installed in a panel?
Unlike standard QO breakers that plug onto a busbar, this QOU breaker is a unit-mount device with box lugs on both the line and load sides. It can be surface-mounted, flush-mounted, or attached to a standard 35mm DIN rail using a compatible mounting foot.
Is this breaker compatible with standard Square D QO load centers?
No. The QOU3100-1021 is a unit-mount breaker designed for OEM panels, control panels, and standalone enclosures. It does not have the plug-on or bolt-on clips required for standard QO or NQ panelboard busbars.
What type of wire connections does the QOU3100-1021 support?
It features slotted box lugs on both the line and load sides. These terminals accept either copper or aluminum conductors ranging from 12 AWG to 2/0 AWG.
Can the QOU3100-1021 be used for DC control circuits?
Yes, in addition to its 120/240V AC rating, this thermal-magnetic breaker is rated for 60V DC applications, providing a 5kA interrupting capacity for DC control panels or battery circuits.
How should the shunt trip coil be wired for safe operation?
The shunt trip coil leads must be connected to a momentary or maintained control circuit providing 120V to 240V AC. Applying voltage to these leads will instantly trip the breaker mechanism, disconnecting power to the load.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 106 reviews.
Reviews Summary
Generated by AI from 99 most recent customer reviews
Last updated 5/14/26
Customers say these circuit breakers function properly and arrive quickly. Many reviews highlight fast shipping, competitive pricing, and reliable product condition upon arrival. Users appreciate the wide selection, including hard-to-find models, and note the breakers work as expected for various applications. Common feedback addresses quick order processing and easy website navigation. Most customers report satisfaction with value and delivery speed, with many indicating they will purchase again.
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Rating
106 reviews
- HLHOMETIGO L.Verified BuyerReviewingSquare D QOU260 - 60A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/7/26Good thing
i recommend this for you
- RGRobert G.Verified BuyerReviewingSquare D QOU340 - 40A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/3/26Circuit breakers
I appreciate the fact that you had these in stock. my Square D distributor does not seem to stock these anymore and it takes a couple weeks to get. your pricing is inline with theirs.
- THTiffany H.Verified BuyerReviewingSquare D QOU115 - 15A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/28/26Will use Super Breakers again
Arrived in a timely manner. Exactly what we needed for a job.
- CSCary S.Verified BuyerReviewingSquare D QOU250 - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/12/26Just what I ordered
Just what I needed for dock pedestal
- MHMark H.Verified BuyerReviewingSquare D QOU250VH - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/11/26Square D QOU250VH - 50A 2 Pole Miniature Circuit Breaker
Was just what I expected!