Square D A1B340 Molded Case Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Square D
A1B340
Molded Case Circuit Breaker
Brand
Square D
SKU
A1B340
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Square D A1B340 - 40A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Similar Items
30A 3 Pole Molded Case Circuit Breaker
15A 3 Pole Molded Case Circuit Breaker
100A 3 Pole Molded Case Circuit Breaker
Description
Rated for 40 amps, the Square D A1B340 is a 3-pole miniature molded case circuit breaker. It incorporates a Visi-Trip indicator, allowing personnel to quickly locate tripped circuits. This breaker is configured to bolt into legacy Square D NA1B panelboards. It offers an essential replacement option for facilities relying on these classic 240V enclosures. With a 10 kAIC rating at 240VAC, it utilizes fixed thermal-magnetic trip technology. Load side lugs accept 8-2 AWG wiring.Specifications
| Brand | Square D |
|---|---|
| Series | A1B |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | A1B |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NA1B 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 | Shunt Trip, Auxiliary Switch, Undervoltage Release |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Long Body, Visual Trip Indicator |
Product FAQs
7 answersWhat panelboards are compatible with the Square D A1B340 circuit breaker?
The A1B340 is specifically engineered to mount into legacy Square D NA1B panelboards. It provides a direct bolt-on replacement to maintain older commercial and industrial distribution systems without requiring a complete panel upgrade.
Is the A1B340 suitable for 3-phase systems?
Yes, as a 3-pole breaker, the A1B340 is designed for 3-phase electrical systems. It provides simultaneous disconnect and overcurrent protection across all three phases in compatible NA1B panels.
How is the A1B340 secured inside the panelboard?
This breaker utilizes a bolt-on connection, meaning it mechanically fastens directly to the busbars of an NA1B panelboard. This ensures a highly secure, vibration-resistant contact compared to plug-on alternatives.
What type of wiring is permitted for the A1B340 lugs?
The factory-installed lugs accept both copper (Cu) and aluminum (Al) conductors ranging from 8 AWG to 2 AWG. Always ensure proper torque specifications are met during installation to prevent thermal issues.
Can the A1B340 be used in DC circuits?
Yes, while primarily used in 240VAC systems with a 10 kAIC rating, the A1B340 is also rated for 48VDC applications, making it suitable for specific low-voltage direct current control or battery circuits.
How does the thermal-magnetic trip unit in the A1B340 operate?
The fixed thermal-magnetic mechanism provides dual-level protection (LI). The thermal element responds to sustained overloads by heating and tripping over time, while the magnetic element provides instantaneous tripping in the event of a severe short circuit.
Is the A1B frame still used for new installations?
The A1B series is a legacy frame primarily sourced to service and maintain existing vintage infrastructure. It is not typically used for new construction, but exact replacements like the A1B340 keep older NA1B panels operational.
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 5.0 out of 5 based on 2 reviews.
Total 5 star reviews: 2 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
Search
Rating
2 reviews
- NLNoble L.ReviewingSquare D A1B115 - 15A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/19/21Great Service, On Time Delivery, Great Price
SuperBreakers is my a dependable source to meet my customer's requirements at a good value and with on time delivery. When you throw in great customer service, you can't beat that combination.
- CHCobe H.ReviewingSquare D A1B120 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars2/11/19Repeat customer
Although these breakers are refurbished they work great. It beats having to change the whole panel because of one breaker.