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Eaton / Cutler-Hammer LA3300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- Bolt-On
Eaton / Cutler-Hammer
LA3300
Molded Case Circuit Breaker
Brand
Eaton / Cutler-Hammer
SKU
LA3300
Quantity
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Eaton / Cutler-Hammer LA3300 - 300A 3 Pole Molded Case Circuit Breaker
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Description
Engineered for heavy-duty industrial applications, the Eaton LA3300 delivers robust 300-amp overcurrent protection. This three-pole molded case circuit breaker utilizes a proven thermal-magnetic trip unit to safeguard critical electrical infrastructure. The unit installs into legacy Westinghouse PRL4 panelboards and motor control centers. Serving as an exact cross-reference for KD3300 models, it features an interchangeable trip unit with adjustable magnetic settings and a 30kA rating at 480V.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | LA3300-R |
| Series | LA |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC, 10kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Westinghouse PRL4 Panelboards, Switchboards, Motor Control Centers |
| Wire Gauge | (1) 4 AWG-600 kcmil (Al/Cu) or (2) 3/0 AWG-250 kcmil (Al/Cu) |
| Max Wire | 600 kcmil |
| Min Wire | 4 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 |
|---|---|
| Accessories | Line and Load Lugs Included |
| Standards | NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Interchangeable Trip Unit |
Product FAQs
8 answersCan I use dual conductors with the standard lugs on the LA3300?
Yes, the standard mechanical lugs on the LA3300 accept either a single conductor from 4 AWG to 600 kcmil or dual conductors from 3/0 AWG to 250 kcmil. The lugs are dual-rated for both aluminum and copper (Al/Cu) wire.
Which panelboards are designed to accept the LA3300 breaker?
This breaker is designed for use in legacy Westinghouse PRL4 panelboards, as well as compatible switchboards and motor control centers. It utilizes a standard bolt-on mounting configuration specific to legacy L-frame enclosures.
Are the trip settings on the LA3300 adjustable?
The LA3300 features a thermal-magnetic trip unit with a fixed thermal element for long-time overload protection. The magnetic element is adjustable, allowing you to fine-tune the instantaneous short-circuit trip threshold to suit your specific load requirements.
What does the LI trip function code mean on the LA3300?
The LI designation indicates that the breaker provides Long-Time (L) and Instantaneous (I) protection. The long-time function protects against sustained overloads, while the instantaneous function protects against sudden short circuits.
Is the LA3300 still manufactured, or is there a direct replacement?
The LA3300 is an obsolete legacy breaker originally manufactured by Westinghouse and later Cutler-Hammer. In many applications, Eaton's KD3300 (Series C) serves as a direct cross-reference and replacement, though you should verify panelboard mounting and dimensions before retrofitting.
Is the LA3300 rated for use in direct current (DC) applications?
Yes, the LA3300 is rated for up to 250V DC with an interrupting capacity of 10kA. When applying this breaker in DC circuits, ensure your wiring and enclosure are properly configured for DC fault interruption.
What frame size does the LA3300 use?
The LA3300 is built on the legacy Westinghouse and Cutler-Hammer L-Frame. This frame designation is critical when sourcing mounting hardware or verifying fitment in older PRL4 panelboards and motor control centers.
What safety checks should be performed before installing a legacy LA3300 breaker?
Before installing any legacy breaker like the LA3300, a qualified electrician should verify the integrity of the casing, ensure the mechanical toggle operates smoothly, and confirm that the adjustable magnetic trip dials are set correctly for the protected circuit. Always de-energize the panelboard before installation.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 13 reviews.
Total 5 star reviews: 13 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
13 reviews
- RGRobert G.Verified BuyerReviewingSquare D LA36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/16/26LA36400
Perfectly boxed and arrived on time. Thanks for the shirt and stickers as well.
- CECraig E.Verified BuyerReviewingEaton / Cutler-Hammer LA3600 - 600A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars10/13/25Westinghouse breaker
Excellent customer service and quick shipping
- CLClifton L.Verified BuyerReviewingSquare D LA36400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/30/25estimator
Good
- BCBenjamin C.Verified BuyerReviewingEaton / Cutler-Hammer LA3225 - 225A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/4/25Refurbished Breaker
Breaker seems to be working great, no complaints from Client
- JMJerry M.ReviewingEaton / Cutler-Hammer LA3400 - 400A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/14/23Where is my breaker?
Where is my breaker?