Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Eaton / Cutler-Hammer HKD3125 Molded Case Circuit Breaker
- 125A
- 3 Pole
- Panel Mount
Eaton / Cutler-Hammer
HKD3125
Molded Case Circuit Breaker
Brand
Eaton / Cutler-Hammer
SKU
HKD3125
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Eaton / Cutler-Hammer HKD3125 - 125A 3 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Eaton / Cutler-Hammer HKD3125 - 125A 3 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | HKD3125 |
| Series | HKD |
| Amperage | 125A |
| Poles | 3 |
| Mounting Style | Panel Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 35kA @ 600VAC, 22kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Eaton Series C Panelboards, Switchboards, Motor Control Centers |
| Wire Gauge | 3 AWG - 350 kcmil |
| Max Wire | 350 kcmil |
| Min Wire | 3 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Motor Operator |
|---|---|
| Accessories | Line and Load Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB-1, UL 489 |
| Approval | CE, CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | High Interrupting Capacity, HACR Rated, Reverse Feed, Interchangeable Trip Unit, Trip-Free Mechanism, Quick-Make/Quick-Break |
Quantity
Eaton / Cutler-Hammer HKD3125 - 125A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | HKD3125-R |
| Series | HKD |
| Amperage | 125A |
| Poles | 3 |
| Mounting Style | Panel Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 35kA @ 600VAC, 22kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Eaton Series C Panelboards, Switchboards, Motor Control Centers |
| Wire Gauge | 3 AWG - 350 kcmil |
| Max Wire | 350 kcmil |
| Min Wire | 3 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Motor Operator |
|---|---|
| Accessories | Line and Load Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB-1, UL 489 |
| Approval | CE, CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | High Interrupting Capacity, HACR Rated, Reverse Feed, Interchangeable Trip Unit, Trip-Free Mechanism, Quick-Make/Quick-Break |
Similar Items
100A 3 Pole Molded Case Circuit Breaker
175A 3 Pole Molded Case Circuit Breaker
200A 3 Pole Molded Case Circuit Breaker
Description
Built for industrial applications, the Eaton HKD3125 is a 3-pole, 125A Series C molded case circuit breaker. It utilizes a robust K-frame architecture to provide consistent long-time and instantaneous protection. This panel-mounted unit installs into Eaton switchboards, motor control centers, and panelboards. It serves as an exact replacement for legacy KD3125 breakers, simplifying facility maintenance. Rated for 600VAC, it delivers 65kAIC at 480V with reliable thermal-magnetic trip technology.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | HKD3125 |
| Series | HKD |
| Amperage | 125A |
| Poles | 3 |
| Mounting Style | Panel Mount |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 100kA @ 240VAC, 65kA @ 480VAC, 35kA @ 600VAC, 22kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Eaton Series C Panelboards, Switchboards, Motor Control Centers |
| Wire Gauge | 3 AWG - 350 kcmil |
| Max Wire | 350 kcmil |
| Min Wire | 3 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch, Padlock Attachment, Motor Operator |
|---|---|
| Accessories | Line and Load Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB-1, UL 489 |
| Approval | CE, CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | High Interrupting Capacity, HACR Rated, Reverse Feed, Interchangeable Trip Unit, Trip-Free Mechanism, Quick-Make/Quick-Break |
Product FAQs
6 answersCan I use the Eaton HKD3125 to replace an older Westinghouse HKD3125 breaker?
Yes. Eaton acquired the Westinghouse distribution equipment line. The Cutler-Hammer or Eaton HKD3125 is a direct, drop-in replacement for the legacy Westinghouse breaker with the exact same catalog number and Series C K-frame dimensions.
What is the difference between the Eaton KD3125 and the HKD3125?
The difference is the short-circuit interrupting rating. The standard KD3125 is rated for 35 kAIC at 480V, while the HKD3125 is the high-interrupting version rated for 65 kAIC at 480V. Both share the same physical K-frame dimensions.
What lug kit is standard for the HKD3125 circuit breaker?
The standard aluminum/copper line and load lug kit for this 125A K-frame breaker is the TA300K. This kit accepts wire sizes from 3 AWG up to 350 kcmil.
Is the HKD3125 suitable for reverse feed applications?
Yes. Eaton Series C K-frame circuit breakers with non-interchangeable thermal-magnetic trip units are suitable for reverse feed use. Always verify that no voltage is present before servicing reverse-fed equipment.
How do I adjust the trip settings on the HKD3125?
This breaker features a thermal-magnetic trip unit with fixed long-time (thermal) protection and adjustable instantaneous (magnetic) protection. The magnetic trip can be adjusted using the dial on the front of the breaker, typically allowing settings between 5 and 10 times the continuous 125A rating.
What types of enclosures or equipment will accept this K-frame breaker?
The HKD3125 is designed for panel mount installations in Eaton Series C panelboards, switchboards, and motor control centers that are configured to accept K-frame breakers.
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 4 reviews.
Total 5 star reviews: 4 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
Search
Rating
4 reviews
- ASAaron S.Verified BuyerReviewingEaton / Cutler-Hammer HKD3400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/13/26Worked as advertised
Don't forget the lug kit if needed
- LHLarry H.Verified BuyerReviewingEaton / Cutler-Hammer HKD3200 - 200A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/19/25It was great
New breaker
- CSCatherine S.ReviewingEaton / Cutler-Hammer HKD3400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/24/22Great
Great Service / Prompt Delivery
- FSFrank S.ReviewingEaton / Cutler-Hammer HKD3400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars10/23/17Breaker purchase
Purchased breaker at a great price, was in stock and shipped it out right away. Will shop at this site again in the future.