Square D QOB350VH1021 Miniature Circuit Breaker
- 50A
- 3 Pole
- Bolt-On
Quantity
Square D QOB350VH1021 - 50A 3 Pole Miniature Circuit Breaker
New
Quantity
Description
Part of the QO family, the Square D QOB350VH1021 is a 50A miniature breaker equipped with a factory-installed shunt trip mechanism, enabling remote shutdown capabilities for automated control systems. This device mounts into Square D NQ and NQOD panelboards using a secure bolt-on connection that prevents loosening over time. Rated for a 22kAIC interrupting capacity at 120/240VAC, it offers superior protection against high fault currents and features a Visi-Trip indicator.Specifications
| Brand | Square D |
|---|---|
| Series | QOB |
| Amperage | 50A |
| 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, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (120/208/240VAC) |
| Standards | UL 489, CSA C22.2 No. 5, HACR |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated, Common Trip, High Interrupting Capacity |
Product FAQs
6 answersWhat does the 1021 suffix indicate on the QOB350VH1021 catalog number?
The 1021 suffix signifies that this breaker includes a factory-installed 120/240V AC shunt trip accessory. This allows the breaker to be tripped remotely by an external voltage signal.
What does the VH designation mean in the QOB350VH1021 part number?
The VH indicates a very high interrupting rating. This specific model provides a 22kAIC rating at 120/240V AC, which is higher than the 10kAIC rating found on standard QOB breakers.
Can the QOB350VH1021 be installed in a standard Square D QO residential load center?
No. The QOB series features a bolt-on mounting design intended for commercial NQ and NQOD panelboards. Standard QO load centers require plug-on breakers.
How does the QOB350VH1021 connect to the panelboard?
It features a bolt-on connection that secures directly to the busbar using screws. This provides a highly secure mechanical and electrical connection favored in commercial environments, unlike standard plug-on breakers.
What type of protection does the QOB350VH1021 provide?
It utilizes a fixed thermal-magnetic trip unit to provide both long-time overload protection and instantaneous short-circuit protection. The integrated shunt trip also allows for remote emergency shutdown capabilities.
What wire sizes are accepted by the terminals on the QOB350VH1021?
The box lugs on this 50A breaker accept either aluminum or copper conductors ranging from 8 AWG to 2 AWG. Ensure proper torque specifications are followed during installation.
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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