Square D EJB34040SA Miniature Circuit Breaker
- 40A
- 3 Pole
- Bolt-On
Quantity
Square D EJB34040SA - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
Description
The EJB34040SA is a 3-pole, 40-amp miniature circuit breaker manufactured by Square D. Designed for commercial and industrial applications, this E-Frame device delivers reliable thermal-magnetic protection for electrical systems. This unit bolts into Square D NF panelboards and accepts 14-2/0 AWG copper or 12-2/0 AWG aluminum wire. It features a Visi-Trip indicator to quickly identify tripped circuits. Rated for 65 kAIC at 480Y/277VAC, the breaker includes a factory-installed 120V shunt trip.Specifications
| Brand | Square D |
|---|---|
| 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 Thermal, Fixed Magnetic |
| Available Options | Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs Included, Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, NEMA AB 1, NFPA 70, UL 489 |
| Approval | CSA, cULus, HACR, HID, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, HID Rated, Visual Trip Indicator |
Product FAQs
6 answersWhat does the "SA" suffix mean on the EJB34040SA?
The "SA" suffix indicates that this breaker includes a factory-installed 120VAC shunt trip. This feature allows the breaker to be tripped remotely for emergency disconnects, fire alarm integration, or automated control systems.
How many panel spaces does the EJB34040SA require?
Because it includes a factory-installed shunt trip accessory, this 3-pole breaker requires four pole spaces in your panelboard.
Can I field-install a shunt trip on a standard EJB34040 instead?
No. Electrical accessories for Square D E-frame breakers, including shunt trips, are factory-installed only and cannot be added in the field. You must order the EJB34040SA if you require a 120V shunt trip.
Which panelboards are compatible with the EJB34040SA?
This bolt-on E-frame breaker is designed exclusively for Square D NF series panelboards. It is not compatible with NQ, I-Line, or QO load centers.
What is the difference between the EJB34040SA, EGB34040SA, and EDB34040SA?
The difference lies in their interrupting capacity (AIC). The EJB series provides the highest rating at 65kAIC at 480Y/277VAC. The EGB series is rated for 35kAIC, and the EDB series is rated for 18kAIC at the same voltage. All three share the same physical footprint and NF panelboard compatibility.
Can the EJB34040SA be used on a 480V Delta electrical system?
No. The 480Y/277VAC rating means this breaker is strictly for use on solidly grounded Wye systems where the line-to-ground voltage does not exceed 277V. It is not rated for 480V Delta systems.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 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.