Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
-4%
Square D QO3701021 Miniature Circuit Breaker
- 70A
- 3 Pole
- Plug-On
Square D
QO3701021
Miniature Circuit Breaker
Brand
Square D
SKU
QO3701021
-4%
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Square D QO3701021 - 70A 3 Pole Miniature Circuit Breaker
New
Quantity
Similar Items
QO3601021 - 60A 3 Pole Miniature Circuit Breaker
50A 3 Pole Miniature Circuit Breaker
100A 3 Pole Miniature Circuit Breaker
Description
The QO3701021 is a 3-pole, 70A miniature circuit breaker built for commercial applications. It features a factory-installed 120/208/240VAC shunt trip, allowing the unit to be tripped remotely. This plug-on breaker mounts into Square D QO load centers and NQ panelboards. It accepts 8-2 AWG copper or aluminum wiring through standard box lug terminals. Rated for 10kAIC at 240VAC, it utilizes thermal-magnetic trip technology. It includes the Visi-Trip indicator and is HACR rated.Specifications
| Brand | Square D |
|---|---|
| Part Number | QO3701021 |
| Series | QO |
| Amperage | 70A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC, 120/240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC, 10kA @ 120/240VAC |
| Frame Type | QO |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | QO Load Centers, NQ Panelboards |
| Wire Gauge | 8-2 AWG (Cu/Al) |
| Max Wire | 2 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (120/208/240VAC) |
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated |
Product FAQs
7 answersWhat does the 1021 suffix indicate on the QO3701021 part number?
The 1021 suffix designates a factory-installed shunt trip accessory. This allows the circuit breaker to be tripped remotely via a separate control circuit operating at 120V, 208V, or 240V AC.
How many panel spaces are required to install this breaker?
The QO3701021 requires four total pole spaces in your load center or panelboard. The 3-pole breaker occupies three spaces, and the factory-installed shunt trip accessory requires one additional space.
Is this breaker compatible with Square D Homeline load centers?
No. QO series breakers have a specific plug-on mounting clip that is not compatible with Homeline panels. This unit is strictly for use in Square D QO load centers and NQ panelboards.
Can I field-install an auxiliary switch or alarm contact on this unit?
No. Square D QO miniature circuit breakers can only accommodate one accessory at a time. Since this model comes with a factory-installed shunt trip, no additional electrical accessories can be added.
Does this circuit breaker include the Visi-Trip feature?
Yes. It features the standard Square D Visi-Trip indicator. When the breaker trips due to an overcurrent or shunt trip activation, the handle snaps to a center position and a bright red flag appears in the indicator window.
Is this breaker suitable for HVAC equipment?
Yes, this breaker is HACR rated. It is certified for use with multi-motor and combination loads typically found in heating, air conditioning, and refrigeration systems.
Does a fault on one phase trip all three poles simultaneously?
Yes. This is a common trip breaker. An overcurrent or short circuit condition on any single pole, or activation of the shunt trip, will cause the internal mechanism to open all three poles at the same time.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
100 SuperPoints = $1 off.
Warranties
Add an extra year of protection
60-Day Warranty
Your purchase includes 60 days of SuperBreakers warranty coverage.
Add a 1-year warranty extension in your cart.
Get a Quote
Don’t see what you’re looking for?
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
Same Day Shipping
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.
Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 285 reviews.
Reviews Summary
Generated by AI from 100 most recent customer reviews
Last updated 6/13/26
Customers say these circuit breakers arrive quickly and work as described. Fast shipping and competitive pricing are frequently mentioned, with many noting same-day or next-day delivery. Users appreciate the wide inventory, particularly for hard-to-find older-style models unavailable locally. The products function reliably and arrive in good condition. Most customers report straightforward ordering and positive interactions. However, some experienced delivery delays or received incorrect items requiring reordering. A few noted concerns about condition upon arrival or customer service responsiveness.
Search
Rating
285 reviews
- 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
- JCJerry C.Verified BuyerReviewingSquare D QO250 - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/8/26Great quality
No issues