B-Line Eaton Series C electron...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$14,328.33
B-Line Eaton Series C electronic , K-, KD, Complete , OPTIM 550, Electronic LSIA trip type, Three-pole, 125A, 600 Vac, 250 Vdc, 65 kAIC at 240 Vac, 3

B-Line Eaton Series C electronic , K-, KD, Complete , OPTIM 550, Electronic LSIA trip type, Three-pole, 125A, 600 Vac, 250 Vdc, 65 kAIC at 240 Vac, 3

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Model: KD3125T57W
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$14,328.33
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Eaton Series C electronic molded case circuit breaker, K-frame, KD, Complete breaker, OPTIM 550, Electronic LSIA trip type, Three-pole, 125A, 600 Vac, 250 Vdc, 65 kAIC at 240 Vac, 35 kAIC at 480 Vac, Without terminals, 50/60 Hz

Manufacturer Resources

Product Specs

Amperage Rating:
125A
Certifications:
UL Listed
Circuit Breaker Frame Type:
Complete breaker
Circuit Breaker Type:
KD
Frame:
K-frame
Frequency Rating:
50/60 Hz
Interrupt Rating:
65 kAIC at 240 Vac, 35 kAIC at 480 Vac
Number Of Poles:
Three-pole
Product Height:
5.5 IN
Product Length Depth:
4.1 IN
Product Weight:
11.5 LB
Product Width:
5.5 IN
Series:
Series C
Terminals:
Without terminals
Trip Type:
Electronic LSIA
Voltage Rating:
600 Vac, 250 Vdc
Department:
Electrical

B-LINE KD3125T57W – Frequently Asked Questions

1) Does the Eaton KD3125T57W breaker come with lugs or terminals?
No. The KD3125T57W ships without terminals, so you have to order the K-frame terminal lugs or a bus connection kit separately to land your conductors. Budget for that before the install date, because the breaker body alone will not accept cable as shipped.
2) What is the interrupting rating of the Eaton Series C KD 125A breaker at 480V?
35 kAIC at 480 Vac, and 65 kAIC at 240 Vac. If your available fault current at the point of installation exceeds 35 kA on a 480 Vac system, this K-frame breaker is not adequately rated and you need a higher AIC frame or a series-rated combination.
3) Will this 125A three-pole breaker work on a 600 volt system?
Yes, it's rated 600 Vac and 250 Vdc, three-pole, at 50/60 Hz. That covers 208, 240, 480 and 600 Vac three-phase service. Just note the interrupting rating steps down as voltage rises: 65 kAIC at 240 Vac and 35 kAIC at 480 Vac.
4) Will a KD-frame 125A Eaton breaker fit in my existing panel enclosure?
The breaker measures 5.5 in high, 5.5 in wide and 4.1 in deep, which is the standard Eaton K-frame footprint. Check that against your enclosure gutter space and the mounting pan, and remember you need extra depth and side clearance for the terminal lugs you add separately, since none are supplied.
5) What does the OPTIM 550 electronic LSIA trip unit do that a thermal-magnetic breaker doesn't?
The KD3125T57W uses an OPTIM 550 electronic LSIA trip unit: long time, short time, instantaneous and ground fault alarm. That gives you adjustable pickup and delay bands so you can coordinate selectively with upstream and downstream devices, which a fixed thermal-magnetic K-frame breaker cannot do. If you only need straight overcurrent protection on a feeder with no coordination study, a thermal-magnetic KD is the simpler buy.
6) Is this a complete breaker or just a trip unit replacement?
It's a complete breaker. The KD3125T57W is the full K-frame assembly with the OPTIM 550 electronic trip unit, not a standalone trip unit, rating plug, or interior. Weight is 11.5 lb.
7) Is the Eaton Series C KD3125T57W UL Listed for use in a commercial building?
Yes, it's UL Listed. For an institutional or MRO spec, the citable ratings on this unit are UL Listed, 600 Vac / 250 Vdc, 125A, three-pole, 50/60 Hz, with 65 kAIC at 240 Vac and 35 kAIC at 480 Vac.
8) I'm replacing a 125A feeder breaker. What exactly do I order to match this one?
Order by the catalog number KD3125T57W. That designation gives you the Series C K-frame, KD type, three-pole, 125A complete breaker with the OPTIM 550 electronic LSIA trip unit and no terminals. Any deviation in the suffix changes the trip unit or accessory configuration, so match the full number rather than just the amp rating and pole count.
9) Can I use this breaker on a 250 VDC circuit?
Yes. The KD3125T57W carries a 250 Vdc rating alongside its 600 Vac rating, so it can be applied on DC systems up to 250 volts. The published interrupting ratings, 65 kAIC and 35 kAIC, are AC values at 240 and 480 Vac.
How fast can I get the B-LINE KD3125T57W delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the B-LINE KD3125T57W come with a warranty?
Absolutely. The B-LINE KD3125T57W is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the B-LINE KD3125T57W?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the B-LINE KD3125T57W from ZenSupply?
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