Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Square D EJB34040 Miniature Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Square D
EJB34040
Miniature Circuit Breaker
Brand
Square D
SKU
EJB34040
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Square D EJB34040 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
Quantity
Square D EJB34040 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Square D |
|---|---|
| Part Number | EJB34040 |
| Series | EJB |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 120VAC, 100kA @ 240VAC, 65kA @ 480Y/277VAC |
| Frame Type | EJB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NF Panelboards |
| Wire Gauge | 14-2/0 AWG (Cu), 12-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 14 AWG (Cu), 12 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs |
| Standards | CSA C22.2 No. 5, HACR, HID, NEMA AB 1, NFPA 70, UL 489 |
| Approval | CSA, cULus, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, HID Rated, Common Trip |
Quantity
Square D EJB34040 - 40A 3 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Part Number | EJB34040-R |
| Series | EJB |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 120VAC, 100kA @ 240VAC, 65kA @ 480Y/277VAC |
| Frame Type | EJB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NF Panelboards |
| Wire Gauge | 14-2/0 AWG (Cu), 12-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 14 AWG (Cu), 12 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs |
| Standards | CSA C22.2 No. 5, HACR, HID, NEMA AB 1, NFPA 70, UL 489 |
| Approval | CSA, cULus, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, HID Rated, Common Trip |
Similar Items
35A 3 Pole Miniature Circuit Breaker
50A 3 Pole Miniature Circuit Breaker
30A 3 Pole Miniature Circuit Breaker
Description
Built for commercial applications, the Square D EJB34040 is a 3-pole, 40A miniature circuit breaker. It delivers reliable thermal-magnetic protection for distribution circuits. This E-Frame breaker installs into Square D NF panelboards using a sturdy bolt-on connection. It includes standard lugs accommodating 14-2/0 AWG copper wiring. With a 65kAIC rating at 480Y/277V, it ensures safety during faults. The unit features a Visi-Trip indicator and carries HACR and HID ratings.Specifications
| Brand | Square D |
|---|---|
| Part Number | EJB34040 |
| Series | EJB |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 100kA @ 120VAC, 100kA @ 240VAC, 65kA @ 480Y/277VAC |
| Frame Type | EJB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NF Panelboards |
| Wire Gauge | 14-2/0 AWG (Cu), 12-2/0 AWG (Al) |
| Max Wire | 2/0 AWG |
| Min Wire | 14 AWG (Cu), 12 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Lugs |
| Standards | CSA C22.2 No. 5, HACR, HID, NEMA AB 1, NFPA 70, UL 489 |
| Approval | CSA, cULus, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, HID Rated, Common Trip |
Product FAQs
6 answersWhat is the difference between the EDB34040, EGB34040, and EJB34040 circuit breakers?
These breakers share the same physical footprint and are all used in Square D NF panelboards, but they have different interrupting capacities at 480Y/277VAC. The EDB34040 is rated for 18 kAIC, the EGB34040 for 35 kAIC, and the EJB34040 offers the highest protection in this frame class at 65 kAIC.
Can the EJB34040 be installed in 480V ungrounded or corner-grounded delta systems?
No. Because the EJB34040 carries a 480Y/277VAC slash voltage rating, NEC requirements restrict it to solidly grounded wye systems where the voltage to ground does not exceed 277V. However, it is UL Listed for use on 240V corner-grounded delta systems.
What are the terminal torque specifications for the EJB34040?
The standard aluminum lugs on this breaker require a tightening torque of 34.5 lb-in for 14 to 10 AWG wire, and 49.6 lb-in for 8 to 2/0 AWG wire.
Does the EJB34040 include a tripped state indicator?
Yes, this E-frame breaker features the Square D Visi-Trip indicator. If the breaker trips due to an overcurrent or short circuit event, the handle rests in a center position and a bright red indicator appears, allowing maintenance personnel to quickly identify the faulted circuit.
Which panelboards are compatible with the EJB34040 circuit breaker?
The EJB34040 is specifically designed for bolt-on installation in Square D NF series panelboards. It is not compatible with NQ panelboards or I-Line panelboards.
Is the EJB34040 suitable for HVAC and lighting applications?
Yes, the EJB34040 is UL Listed as HACR type, making it approved for heating, air conditioning, and refrigeration motor loads. It is also UL Listed as HID (High-Intensity Discharge), allowing it to switch high-inrush commercial lighting circuits.
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 12 reviews.
Total 5 star reviews: 11 Total 4 star reviews: 1 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
Search
Rating
12 reviews
- EOEric O.Verified BuyerReviewingSquare D EJB14040 - 40A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/5/26Breaker Replacement
I needed a replacement breaker fast, and SuperBreakers pulled it off for me without any issues.
- BBBrad B.Verified BuyerReviewingSquare D EJB34125 - 125A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars6/27/26Breaker Order
Thanks! Ordering was easy and the part was delivered quickly and accurately. All I can ask for!
- RRRodolfo R.Verified BuyerReviewingSquare D EJB34015 - 15A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars1/14/26Satisfied Customer
The breaker was received in good condition and it works good. Lead time was not long it all.
Very happy with SuperBreakers Rep. Good customer service.
- RNRandy N.Verified BuyerReviewingSquare D EJB34070 - 70A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars11/14/25Breaker value
saved a lot compared to what the electrician wanted to charge us, at least half the price.
- TWTimothy W.Verified BuyerReviewingSquare D EJB34020 - 20A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars10/15/25Circuit Breaker
Product arrived in a timely matter and met expectations to repair the problem that we had.