Square D KI36125 Molded Case Circuit Breaker

The KI36125 is designed exclusively for Square D I-Line panelboards and switchboards. It utilizes an I-Line style plug-on connection for the busbar and standard lugs on the load side.

The KI36125 is part of the legacy K-Frame series. While it serves as an exact replacement for existing installations, new panel upgrades are typically transitioned to the PowerPact H-Frame series, specifically the HRA36125.

The KI36125 features a thermal-magnetic trip unit with a fixed thermal element for overload protection and an adjustable magnetic element. The adjustable magnetic setting allows electricians to customize the instantaneous short-circuit response threshold to accommodate motor inrush currents and coordinate with downstream devices.

The load lugs on this breaker accept aluminum or copper wire ranging from 4 AWG to 350 kcmil. Ensure all connections are torqued to the manufacturer specifications printed on the breaker label during installation.

This breaker has a high interrupting rating of 200kAIC at 480VAC, meaning it can safely clear a fault current of up to 200,000 amps without sustaining catastrophic damage. This makes it suitable for industrial applications with high available fault currents.

The LI designation indicates that the breaker provides Long-Time and Instantaneous trip functions. The Long-Time function protects against sustained overloads, while the Instantaneous function provides immediate tripping during severe short circuits.

Yes, the KI36125 is rated for use in systems up to 600VAC. At 600VAC, it has an interrupting capacity of 100kAIC. For 240VAC and 480VAC systems, the interrupting capacity increases to 200kAIC, providing robust protection across various industrial voltage levels.

No, the KI36125 features an I-Line style plug-in connection. The breaker jaws plug directly into the panelboard bus stack, eliminating the need for separate line-side cables or complex mounting hardware.