Square D QOB340VH-1021 QOB340VH1021 - 40A 3 Pole Miniature Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Quantity
Square D QOB340VH1021 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
Description
Engineered for commercial and industrial applications, this Square D miniature circuit breaker features a factory-installed shunt trip mechanism for remote operation. The 40-amp, three-pole device delivers reliable thermal-magnetic protection for demanding electrical systems. Designed specifically for bolt-on installations, it integrates seamlessly into Square D NQ and NQOD panelboards. Rated at 22kAIC, it includes the signature Visi-Trip indicator for rapid fault identification.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOB340VH-1021 |
| Series | QOB |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 120/240VAC |
| Phase | 3 |
| AIC Rating | 22kA @ 120VAC, 22kA @ 240VAC, 22kA @ 120/240VAC |
| Frame Type | QOB |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 8-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Shunt Trip |
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, High Interrupting Capacity |
Product FAQs
5 answersWhich panelboards are compatible with the QOB340VH1021 circuit breaker?
This bolt-on breaker is designed specifically for Square D NQ and NQOD panelboards. It cannot be installed in standard QO load centers, which require plug-on connections.
What does the 1021 suffix indicate on this Square D breaker?
The 1021 suffix means the breaker comes with a factory-installed shunt trip. This accessory includes a coil clearing contact and allows the breaker to be tripped remotely using a 120V to 240V AC control signal.
What does the VH designation mean in the QOB340VH1021 catalog number?
The VH suffix indicates a high interrupting rating. This model provides 22 kA of fault protection at 240V AC, which is higher than the standard 10 kA rating found on base QOB breakers.
Can I use the QOB340VH1021 to replace a QO340VH1021?
No. Although they share the same 40A rating, 22 kA interrupting capacity, and shunt trip accessory, the QOB version features a bolt-on connection for commercial panelboards. The QO version is a plug-on breaker for standard load centers.
How does the thermal-magnetic trip unit function on the QOB340VH1021?
The thermal element provides long-time protection by tripping in response to sustained overloads, while the magnetic element provides instantaneous protection to quickly clear severe short circuits.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 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