Eaton / Cutler-Hammer KDB3300 Molded Case Circuit Breaker
- 300A
- 3 Pole
- Panel Mount
Eaton / Cutler-Hammer
KDB3300
Molded Case Circuit Breaker
Brand
Eaton / Cutler-Hammer
SKU
KDB3300
Quantity
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Eaton / Cutler-Hammer KDB3300 - 300A 3 Pole Molded Case Circuit Breaker
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300A 3 Pole Molded Case Circuit Breaker
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Description
Providing reliable long-time and instantaneous overcurrent defense, this 300A Eaton MCCB is engineered for heavy-duty applications. It fits seamlessly into Series C panelboards and motor control centers, serving as a seamless replacement for the KD3300. Featuring a 35 kAIC interrupt rating at 480V and reverse feed capability, this three-pole breaker comes equipped with standard aluminum terminals to accommodate 250-500 kcmil conductors.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | KDB3300 |
| Series | KDB |
| Amperage | 300A |
| Poles | 3 |
| Mounting Style | Panel Mount |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 35kA @ 480VAC, 25kA @ 600VAC, 10kA @ 250VDC |
| Frame Type | KD |
|---|---|
| Terminal Type | Lugs |
| For Use With | Eaton Series C Panelboards, Motor Control Centers, Switchboards |
| Wire Gauge | 250-500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 250 kcmil |
| 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 | Standard Aluminum Terminals (TA350K) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Reverse Feed, Non-Interchangeable Trip |
Product FAQs
6 answersWhat is the difference between the Eaton KDB3300 and the standard KD3300?
Both are 300-amp, 3-pole K-frame circuit breakers with identical physical dimensions and interrupting ratings. The KDB3300 features a factory-sealed, non-interchangeable thermal-magnetic trip unit, whereas the KD3300 has a field-interchangeable trip unit.
Does the KDB3300 support field-installable internal accessories?
No. Because the KDB3300 utilizes a non-interchangeable trip unit, the breaker is factory-sealed to meet UL 489 requirements. Internal accessories like shunt trips, auxiliary contacts, and undervoltage releases must be installed at the factory.
Is the KDB3300 circuit breaker suitable for reverse feed installations?
Yes. Eaton Series C K-frame breakers with non-interchangeable trip units, including the KDB3300, are fully rated for reverse feed applications.
Can this breaker be used to replace legacy Cutler-Hammer or Westinghouse KD3300 breakers?
Yes. The Eaton Series C KDB3300 shares the exact same physical footprint and mounting dimensions as legacy Cutler-Hammer and Westinghouse KD-frame breakers, making it a direct drop-in replacement for older panelboards and MCCs.
Are KDB3300 thermal-magnetic breakers rated for direct current systems?
Yes. Unlike K-frame breakers equipped with electronic trip units, this thermal-magnetic breaker is UL rated for DC systems up to 250VDC, providing a 10kA interrupting capacity at that voltage.
Can I replace a broken toggle handle on the KDB3300 in the field?
No. KDB breakers are factory-sealed, meaning the internal operating handle mechanism cannot be safely opened or replaced in the field. If the handle mechanism fails, the entire breaker requires replacement or factory repair.
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