Siemens KM2B800 Molded Case Circuit Breaker
- 800A
- 2 Pole
- Bolt-On
Quantity
Siemens KM2B800 - 800A 2 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built for commercial power distribution, the Siemens KM2B800 is a legacy 2-pole, 800A molded case circuit breaker. It utilizes an interchangeable trip unit with adjustable magnetic functions, delivering precise LI defense against overcurrents. This bolt-on breaker mounts into Siemens S4, S5, P4, and P5 panelboards, alongside SB1-SB3 switchboards. It provides a seamless swap for aging infrastructure. If a modern substitute is needed, the HMD62B800 can be used with a retrofit kit.Specifications
| Brand | Siemens |
|---|---|
| Part Number | KM2B800-R |
| Series | KM |
| Amperage | 800A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC |
| Phase | 1 |
| AIC Rating | 65kA @ 240VAC, 50kA @ 480VAC, 22kA @ 600VAC |
| Frame Type | KM |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P4, P5, S4, S5 Panelboards, SB1, SB2, SB3 Switchboards, Motor Control Centers |
| Wire Gauge | 3 Cables: 250-500 kcmil (Cu/Al) OR 2 Cables: 500-750 kcmil (Cu/Al) |
| Max Wire | 750 kcmil |
| Min Wire | 250 kcmil |
| 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, Lug Kits |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | UL 489, CSA C22.2 No. 5 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Interchangeable Trip Unit, Trip-Free Mechanism |
Product FAQs
5 answersWhich Siemens panelboards and switchboards are compatible with the KM2B800 breaker?
This KM frame breaker is designed for installation in Siemens P4, P5, S4, and S5 panelboards. It is also compatible with SB1, SB2, and SB3 switchboards, along with select motor control centers.
What are the wire size requirements for the load side lugs?
The load lugs accommodate multiple conductor configurations. You can use either three copper or aluminum cables sized from 250 to 500 kcmil, or two cables sized from 500 to 750 kcmil per phase.
Does the KM2B800 require line side lugs for installation?
No. Because this is a bolt-on breaker intended for panelboards and switchboards, the line side bolts directly to the internal bus connections. Lugs are only utilized on the load side.
How is the trip unit configured on this KM frame breaker?
It utilizes a thermal-magnetic trip unit with LI (Long-Time and Instantaneous) functions. The thermal element provides fixed overload protection, while the magnetic instantaneous trip point is adjustable to coordinate with specific downstream loads.
Can this breaker replace older ITE branded KM frame breakers?
Yes. Siemens acquired ITE and continued manufacturing the KM frame series to the same physical and electrical specifications. A Siemens KM2B800 will directly replace a legacy ITE KM2B800 without requiring panel modifications.
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