Eaton / Westinghouse HK3175 Molded Case Circuit Breaker

Yes. Eaton acquired the Westinghouse electrical distribution division in the early 1990s. The HK3175 is the exact same Series C K-frame breaker regardless of whether it carries the Westinghouse, Cutler-Hammer, or Eaton brand name.

This Series C K-frame breaker is designed for panel mount applications in legacy Westinghouse and current Eaton Cutler-Hammer panelboards, switchboards, and motor control centers.

The HK3175 is the high-interrupting capacity version of the standard KD3175. While both are 175A Series C K-frame breakers, the HK model provides a higher short-circuit interrupting rating (100kA at 240V and 65kA at 480V) compared to the standard KD model.

The HK3175 features a fixed thermal element for overload protection at 175A and an adjustable magnetic element for short-circuit protection. The magnetic trip dial on the faceplate allows electricians to fine-tune the instantaneous trip threshold to coordinate with downstream devices or motor inrush currents.

Yes. Standard Series C thermal-magnetic breakers like the HK3175 do not have line and load restrictions unless specifically marked on the faceplate. This allows them to be reverse fed in applications such as main breaker backfeeding.

The push-to-trip button on the front of the breaker mechanically tests the tripping mechanism. It should be used during routine maintenance to exercise the breaker, ensuring the internal contacts open freely and do not bind over time.

While primarily used in AC systems, this breaker is rated for 250 VDC applications. When used in DC circuits, electricians must follow the manufacturer wiring diagrams, which often require wiring multiple poles in series to safely interrupt the DC arc.

This breaker typically comes with standard mechanical lugs designed for 3 AWG to 350 kcmil aluminum or copper conductors. If specific lug kits are required for your installation, verify the terminal configuration before mounting to ensure proper wire seating and torque.