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Siemens / ITE KM3B500 Molded Case Circuit Breaker
- 500A
- 3 Pole
- Bolt-On
Siemens / ITE
KM3B500
Molded Case Circuit Breaker
Brand
Siemens / ITE
SKU
KM3B500
Quantity
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Siemens / ITE KM3B500 - 500A 3 Pole Molded Case Circuit Breaker
Re-Certified
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Description
Operating as a high-capacity safeguard, this 500A thermal-magnetic breaker is tailored for industrial 3-phase systems. It provides reliable LI protection functions to maintain stability across 600VAC commercial networks. This component mounts into older ITE panelboards. Choosing this legacy frame ensures a perfect physical fit, eliminating the downtime and expense of installing the LXD63B500 retrofit adapter kit. An interchangeable trip unit highlights its industrial-grade construction.Specifications
| Brand | Siemens / ITE |
|---|---|
| Part Number | KM3B500-R |
| Series | KM |
| Amperage | 500A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 42kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Legacy ITE Switchboards and Panelboards, Motor Control Centers |
| Wire Gauge | (2) 1 AWG - 500 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 1 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 | Lugs |
| Standards | UL 489, CSA C22.2 No. 5.1 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Interchangeable Trip Unit, Trip-Free Mechanism |
Product FAQs
8 answersDoes the KM3B500 feature an interchangeable trip unit?
Yes, it includes an interchangeable thermal-magnetic trip unit. This allows licensed electricians to replace the trip unit to adjust the continuous current rating without replacing the entire frame, provided the new rating stays within the frame's maximum capacity.
How does the adjustable magnetic trip function on this breaker?
The adjustable magnetic setting allows you to customize the instantaneous short-circuit trip point. This is essential for preventing nuisance tripping from high motor inrush currents and for ensuring proper selective coordination with downstream devices.
Can the KM3B500 be reverse fed in a panel?
No. Under UL 489 standards, circuit breakers equipped with interchangeable trip units cannot be reverse fed. Power must flow from the designated line side to the load side.
What equipment is compatible with the KM3B500 breaker?
This legacy M-frame breaker is designed for bolt-on installation in older ITE and Siemens Sentron power panelboards, switchboards, and motor control centers. It serves as an exact-fit replacement that eliminates the need for modern retrofit adapters.
What are the standard lug wire capacities for this breaker?
The included load-side lugs are dual-wire rated, accepting two conductors per phase. They accommodate aluminum or copper wire ranging from 1 AWG to 500 kcmil.
Is the KM3B500 suitable for direct current applications?
Yes, it carries a DC voltage rating up to 250VDC. When used in DC systems, specific wiring configurations, such as wiring poles in series, may be required to ensure proper voltage distribution across the contacts.
What is the modern equivalent to the legacy KM3B500?
While the KM3B500 is a legacy Sentron series component, Siemens has replaced this line with newer families like the VL and 3VA series. However, using the original KM3B500 for replacements avoids the need for panel modifications or retrofit kits.
Why must the trip unit cover seals remain intact on the KM3B500?
The trip unit cover is factory sealed to prevent tampering with the calibration elements. Removing these seals or attempting to alter the internal calibration will void the UL listing and compromise the protective function of the breaker.
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