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Square D EH34040 Molded Case Circuit Breaker
- 40A
- 3 Pole
- Plug-On
Square D
EH34040
Molded Case Circuit Breaker
Brand
Square D
SKU
EH34040
Quantity
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Square D EH34040 - 40A 3 Pole Molded Case Circuit Breaker
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Square D EH34040 - 40A 3 Pole Molded Case Circuit Breaker
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| Brand | Square D |
|---|---|
| Part Number | EH34040 |
| Series | EH |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 14kA @ 480Y/277VAC |
| Frame Type | EH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NEHB Panelboards |
| Wire Gauge | 14-2 AWG (Cu), 12-2 AWG (Al) |
| Max Wire | 2 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 | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Quantity
Square D EH34040 - 40A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Part Number | EH34040 |
| Series | EH |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 14kA @ 480Y/277VAC |
| Frame Type | EH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NEHB Panelboards |
| Wire Gauge | 14-2 AWG (Cu), 12-2 AWG (Al) |
| Max Wire | 2 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 | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
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Description
Designed to protect commercial electrical systems, this 40-amp molded case circuit breaker utilizes fixed thermal and magnetic trip elements. It installs effortlessly into Square D NEHB panelboards, providing a secure plug-on connection for three-phase applications. The unit features a 65kA interrupting rating at 240VAC and includes a highly visible trip indicator for rapid diagnostics. For modern upgrades, this specific E-frame breaker is frequently replaced by the EHB34040 configuration.Specifications
| Brand | Square D |
|---|---|
| Part Number | EH34040 |
| Series | EH |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC, 480Y/277VAC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 14kA @ 480Y/277VAC |
| Frame Type | EH |
|---|---|
| Terminal Type | Lugs |
| For Use With | Square D NEHB Panelboards |
| Wire Gauge | 14-2 AWG (Cu), 12-2 AWG (Al) |
| Max Wire | 2 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 | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | CSA C22.2 No. 5, HACR, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Product FAQs
6 answersWhich panelboards are compatible with the Square D EH34040 breaker?
The EH34040 is specifically designed for legacy Square D NEHB panelboards. It features an NEHB-specific plug-on connection and will not fit in standard NQ, NQOD, or NF panelboards.
Does the EH34040 require a bolt-on connection for 3-phase installation?
No, the EH34040 utilizes a plug-on mounting mechanism that snaps directly onto the NEHB panel bus. If your specific NEHB panel setup requires bolt-on branch breakers, you will need the EHB34040 catalog number instead.
Can the EH34040 be installed on an ungrounded 480V Delta system?
No. Because this breaker carries a 480Y/277VAC slash rating, standard NEC rules restrict its use to solidly grounded wye systems where the phase-to-ground voltage does not exceed 277V. It cannot be used on ungrounded or corner-grounded 480V Delta systems.
Is the Square D EH34040 breaker obsolete?
Yes, Square D has discontinued the EH frame circuit breaker line along with legacy NEHB panelboards. However, the EH34040 remains the required exact replacement part to maintain existing plug-on NEHB infrastructure without upgrading the entire panel.
What is the maximum wire size the EH34040 terminal lugs can accept?
The factory lugs accept up to #2 AWG copper or aluminum wire. Since standard 40-amp circuits usually require much smaller #8 AWG conductors, this oversized lug capacity allows electricians to easily upsize wire to account for voltage drop on long industrial 480V branch runs.
Are the thermal or magnetic trip elements adjustable on the EH34040?
No, this breaker relies on fixed thermal and fixed magnetic trip functions for overload and short-circuit protection. It does not offer adjustable electronic trip dials for selective coordination.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 7 reviews.
Total 5 star reviews: 7 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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Rating
7 reviews
- TSThomas S.Verified BuyerReviewingSiemens EH3B020 - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars11/6/25Great
Thanks
- JMJim M.ReviewingSiemens EH3B040 - 40A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars11/24/23They fit perfectly and saved
They fit perfectly and saved us a lot of money by being able to replace just these breakers
- KHKen H.ReviewingSiemens EH3B030 - 30A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars1/12/23Great service
Great service and products fast shipping
- JSJerry S.ReviewingSiemens / ITE EH3B070 - 70A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars4/20/22Great Price - Breakers Work Fine
My local Supplier was charging me three times the price for a breaker that i bought on super Breakers.
- MRMatt R.ReviewingSiemens EH3B020 - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/6/2020 Amp Breaker
Received item quickly and in great shape. Thank you!!!