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Eaton / Cutler-Hammer BR340 Miniature Circuit Breaker
- 40A
- 3 Pole
- Plug-On
Eaton / Cutler-Hammer
BR340
Miniature Circuit Breaker
Brand
Eaton / Cutler-Hammer
SKU
BR340
Quantity
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Eaton / Cutler-Hammer BR340 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
Quantity
Eaton / Cutler-Hammer BR340 - 40A 3 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | BR340 |
| Series | BR |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | Type BR Load Centers |
| Wire Gauge | 14-4 AWG (Cu/Al) |
| Max Wire | 4 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Lock |
|---|---|
| Standards | UL 489, Federal Specification W-C375 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
Sold out
Quantity
Eaton / Cutler-Hammer BR340 - 40A 3 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | BR340-R |
| Series | BR |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | Type BR Load Centers |
| Wire Gauge | 14-4 AWG (Cu/Al) |
| Max Wire | 4 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Lock |
|---|---|
| Standards | UL 489, Federal Specification W-C375 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
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Description
Delivering reliable 40A protection for three-phase circuits, this thermal-magnetic breaker is an essential component for commercial power distribution. It utilizes a common trip configuration to guarantee simultaneous disconnection across all poles during a fault event. The device is specifically manufactured to fit Eaton and legacy Cutler-Hammer BR style load centers. Box lug terminals accommodate a wide range of wire gauges from 14 to 4 AWG. It features a 10kAIC interrupting capacity.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | BR340 |
| Series | BR |
| Amperage | 40A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | Type BR Load Centers |
| Wire Gauge | 14-4 AWG (Cu/Al) |
| Max Wire | 4 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Padlock Attachment, Handle Lock |
|---|---|
| Standards | UL 489, Federal Specification W-C375 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip, HACR Rated |
Product FAQs
7 answersWhat panels are compatible with the BR340 circuit breaker?
This breaker is designed for use in Eaton and Cutler-Hammer Type BR load centers. It requires three adjacent 1-inch spaces on the panel bus bar.
Is the BR340 an approved replacement for legacy Bryant or Westinghouse breakers?
Yes, Eaton Type BR breakers are UL listed direct replacements for older Bryant, Westinghouse, and Challenger Type BR breakers installed in existing electrical panels.
How many panel spaces does this breaker occupy?
As a 3-pole breaker, it requires three standard 1-inch spaces in a compatible Type BR load center.
What wire gauges are accepted by the lugs on the BR340?
The box lugs are rated for 14 AWG through 4 AWG copper or aluminum conductors. Always ensure your wire sizing complies with current NEC standards for a 40-amp circuit.
Why does my existing panel say Cutler-Hammer but the new breaker says Eaton?
Eaton acquired the Cutler-Hammer brand. Modern Type BR breakers manufactured by Eaton are the exact OEM replacements for legacy Cutler-Hammer BR installations.
How does the trip mechanism function on this 3-pole breaker?
It uses a thermal-magnetic mechanism with a common trip feature. This ensures that an overload or short circuit on any single phase will simultaneously open all three poles, preventing a dangerous single-phasing condition on connected equipment.
How does this breaker connect to the load center?
It utilizes a standard plug-on mounting design. The breaker engages the mounting tabs on the backpan and pushes directly onto the live bus bar for a secure electrical connection.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 70 reviews.
Reviews Summary
Generated by AI from 96 most recent customer reviews
Last updated 8/15/25
Customers say these circuit breakers arrive quickly and fit their needs perfectly. Many reviews mention competitive pricing and reliable availability, particularly for hard-to-find models. The products consistently meet expectations for installation and functionality. Reviews frequently note the precise fit and immediate operation of these breakers. Some users appreciate the option of both new and refurbished units.
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Rating
70 reviews
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In this day and age it can be a challenge at times finding a reputable business that fills your order correctly and at the right price and without delay. I am very pleased with your service. Thank you.