Square D QO340VH1021 Miniature Circuit Breaker
- 40A
- 3 Pole
- Plug-On
Quantity
Square D QO340VH1021 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
Description
Designed for remote disconnect applications, the Square D QO340VH1021 features a factory-installed 120-240VAC shunt trip mechanism. This 40-amp, three-pole miniature circuit breaker delivers reliable thermal-magnetic protection for 240VAC commercial and industrial systems. It installs seamlessly into standard Square D QO load centers, NQ panelboards, and NQOD panelboards. The breaker boasts a high interrupting capacity of 22kAIC and includes the Visi-Trip visual indicator.Specifications
| Brand | Square D |
|---|---|
| Part Number | QO340VH1021 |
| Series | QO |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC, 120/240VAC |
| Phase | 3 |
| AIC Rating | 22kA @ 240VAC, 22kA @ 120/240VAC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | QO Load Centers, 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 | Padlock Attachment |
|---|---|
| Accessories | Shunt Trip |
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated, High Interrupting Capacity |
Product FAQs
7 answersWhat does the 1021 suffix mean on the QO340VH1021 breaker?
The 1021 suffix indicates the breaker includes a factory-installed shunt trip mechanism designed for 120V, 208V, or 240V AC operation. This allows the breaker to be tripped remotely by applying voltage to the accessory terminals.
How many panel spaces does the QO340VH1021 require?
This unit requires 4 panel spaces. Although it is a 3-pole breaker, the factory-installed shunt trip mechanism occupies one additional pole space in the load center or panelboard.
Can I field-install a shunt trip on a standard QO340VH breaker?
No. Square D QO and QOB shunt trips cannot be added in the field. They must be factory-installed, which is why you must order the specific 1021 suffix version if your application requires remote tripping.
What size wire is accepted by the shunt trip terminals on this breaker?
The shunt trip terminals accept up to two 14 AWG to 12 AWG copper wires. The hot and neutral control wires can be connected to either terminal on the shunt trip mechanism.
What is the difference between a standard QO340 and this QO340VH1021 breaker?
The VH designation indicates a higher interrupting capacity of 22kAIC at 240V, compared to the 10kAIC rating of a standard QO breaker. Additionally, the 1021 suffix means this specific model includes a factory-installed shunt trip.
How does the VISI-TRIP feature assist with panel maintenance?
The VISI-TRIP indicator provides a highly visible red flag in the breaker window when it has tripped due to an overcurrent or short circuit. This allows electricians to instantly identify the tripped circuit without having to manually check each breaker handle in a fully populated panel.
What type of protection does the thermal-magnetic trip mechanism provide?
The thermal-magnetic mechanism provides dual protection. The thermal component responds to sustained overloads with a delayed trip, while the magnetic component provides an instantaneous trip response to severe short circuits.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 286 reviews.
- RBRobert B.Verified BuyerReviewingSquare D QO120 - 20A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars10/5/26Square D Q0120-20A circuit breaker
This device was delivered on time as advertised and it was in excellent condition. The installation process was simple and straightforward, and the unit worked perfectly when connected to the electric circuit.
I am completely satisfied and will utilize this component resource for my future electrical needs.
- GCGerard C.Verified BuyerReviewingSquare D QO130GFI - 30A GFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/21/26Great !
I could not find the breaker in hardwood stores. Superbreakers took car of it in a week.
- RHRoy H.Verified BuyerReviewingSquare D QO280 - 80A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/17/26Square D QO280 - 80A 2 Pole Miniature Circuit Breaker
Exactly as described
- KWKevin W.Verified BuyerReviewingSquare D QO120 - 20A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/15/26Great Price
Brand spanking new!
- CEchristopher e.Verified BuyerReviewingSquare D QO115PDF - 15A Dual Function Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/11/26My breakers
Had a hard time locating these breakers locally, when I did find 1 they wanted to charge me triple what superbreakers charged. Items delivered exactly when they said they would, were exactly what I ordered. Appreciated the ease of ordering, definitely my go to from this point on