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Square D QOB2100-1021 QOB21001021 - 100A 2 Pole Miniature Circuit Breaker
- 100A
- 2 Pole
- Bolt-On
Square D
QOB2100-1021
QOB21001021 - 100A 2 Pole Miniature Circuit Breaker
Brand
Square D
SKU
QOB2100-1021
Quantity
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Square D QOB21001021 - 100A 2 Pole Miniature Circuit Breaker
New
Quantity
Quantity
Square D QOB21001021 - 100A 2 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Square D |
|---|---|
| Part Number | QOB21001021 |
| Series | QOB |
| Amperage | 100A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC, 48VDC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC, 5kA @ 48VDC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 4 AWG - 2/0 AWG (Al/Cu) |
| Max Wire | 2/0 AWG |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Tie |
|---|---|
| Accessories | Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Sold out
Quantity
Square D QOB21001021 - 100A 2 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Part Number | QOB21001021-R |
| Series | QOB |
| Amperage | 100A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC, 48VDC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC, 5kA @ 48VDC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 4 AWG - 2/0 AWG (Al/Cu) |
| Max Wire | 2/0 AWG |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Tie |
|---|---|
| Accessories | Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
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Description
Part of the Square D QO family, this 2-pole, 100A miniature circuit breaker is built for commercial and industrial environments. It installs into NQ and NQOD panelboards, utilizing a bolt-on connection for a secure, vibration-resistant fit. The key feature is a factory-installed 120/208/240VAC shunt trip for remote tripping. It also delivers a 10kAIC rating and includes the signature Visi-Trip indicator for rapid fault identification.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOB21001021 |
| Series | QOB |
| Amperage | 100A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC, 48VDC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC, 5kA @ 48VDC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 4 AWG - 2/0 AWG (Al/Cu) |
| Max Wire | 2/0 AWG |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Tie |
|---|---|
| Accessories | Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Product FAQs
6 answersWhat does the -1021 suffix indicate on the QOB2100-1021 circuit breaker?
The -1021 suffix designates that this breaker includes a factory-installed 120/208/240VAC shunt trip accessory. This allows the breaker to be opened remotely via an external control signal.
Which panelboards are compatible with the Square D QOB2100-1021?
This bolt-on miniature circuit breaker is designed specifically for Square D NQ and legacy NQOD panelboards. It cannot be installed in standard QO load centers, which require plug-on breakers.
What is the difference between the QOB2100-1021 and the QO2100-1021?
The QOB2100-1021 is a bolt-on breaker for NQ and NQOD panelboards, while the QO2100-1021 is the plug-on equivalent for standard QO load centers. Both are 100A, 2-pole breakers equipped with a factory-installed shunt trip.
Does the QOB2100-1021 include a visual trip indicator?
Yes, it features the Square D Visi-Trip indicator. When the breaker trips due to an overcurrent or short circuit event, a highly visible red flag appears in the indicator window for rapid fault identification.
How is the factory-installed shunt trip wired on the QOB2100-1021?
The shunt trip accessory features two dedicated terminals. To enable remote tripping, these terminals must be wired to a 120/208/240VAC control power source through a normally open contact, such as an emergency push button or fire alarm relay.
How does the QOB2100-1021 secure to the panelboard bus?
This QOB series breaker utilizes a bolt-on mounting connection. It fastens directly to the panelboard bus with screws, providing a secure, vibration-resistant connection required in many commercial and industrial environments.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 205 reviews.
Reviews Summary
Generated by AI from 100 most recent customer reviews
Last updated 3/11/26
Customers say these electrical breakers arrive exactly as ordered and work perfectly for their intended applications. They consistently praise the competitive pricing, which many report is significantly lower than local suppliers. Fast shipping and prompt delivery are frequently highlighted, with many receiving orders within days or even next-day delivery for urgent needs. The breakers arrive well-packaged and in excellent condition. Many reviews emphasize the company's extensive inventory availability, particularly for hard-to-find breakers. One customer experienced difficulty with order cancellation and was charged a restocking fee, which caused dissatisfaction.
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Rating
205 reviews
- BLBOOSTIX L.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/17/26QOB220
That's nice breakers!
- PHPaul H.Verified BuyerReviewingSquare D QOB330 - 30A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/5/26Quick shipping and delivery
Shipped and delivered on time for installation at one of our projects. Thank you!
- RMRick M.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Project Mgr
Just what I needed.
- DHDoug H.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Square D QOB breakers
As always, our order arrived timely, and accurate. You can’t beat their prices that’s why we have used this company for years.
- RKRyan K.Verified BuyerReviewingSquare D QOB230VH - 30A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars7/1/26Awesome
Worked great