Engineered for commercial and industrial power distribution, the HKB3175 is a 175-amp molded case circuit breaker from Eaton's legacy Mark 75 K-Frame series. It utilizes proven thermal-magnetic trip technology for dependable long-time and instantaneous (LI) overcurrent protection. This panel-mount breaker fits into older Eaton Series C panelboards, Mark 75 panelboards, and switchboards. For modern upgrades, this unit is superseded by the HKD3175 model. Rated for 65 kAIC at 240V.
High Interrupting Capacity, Interchangeable Trip Unit
Product FAQs
5 answers
Can I use the Eaton HKB3175 to replace an older Westinghouse or Cutler-Hammer HKB3175?
Yes. Eaton acquired the Westinghouse and Cutler-Hammer molded case circuit breaker lines. An HKB3175 carries the exact same physical dimensions, K-frame footprint, and electrical characteristics regardless of which of these three brands is printed on the label.
Which panelboards are compatible with the HKB3175 circuit breaker?
This breaker is designed for bolt-on installation in Eaton Series C panelboards, legacy Mark 75 panelboards, and compatible switchboards. It requires a chassis configured to accept standard K-frame breakers.
How does the adjustable magnetic trip function work on this breaker?
The HKB3175 features a thermal-magnetic trip unit with fixed thermal protection for overloads and an adjustable magnetic dial for instantaneous short-circuit protection. This adjustable dial allows electricians to fine-tune the fault clearing threshold to coordinate with downstream devices.
What wire size range do the standard lugs on the HKB3175 accept?
The standard factory lugs accommodate wire sizes from 3 AWG up to 350 kcmil. When terminating conductors, ensure the wire material and temperature ratings align with your specific application requirements and local electrical codes.
Is the HKB3175 rated for direct current applications?
Yes, this breaker is rated for use in DC systems up to 250VDC with an interrupting capacity of 20kA. This makes it suitable for specific industrial DC control panels, transit systems, and battery backup applications.
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