The Westinghouse HFB3110 is a 110-amp, 3-pole, 600V MARK 75 high-interrupting F-Frame molded case circuit breaker. The MARK 75 designation indicates a 75,000A asymmetrical (25kA symmetrical) interrupting capacity at 480V — significantly higher than the standard FB series. This breaker is part of the classic Westinghouse AB DE-ION® series and is electrically interchangeable with the Eaton/Cutler-Hammer HFD3110 Series C replacement. Widely used in industrial facilities, motor control centers, and commercial switchboards requiring higher fault current ratings.
| Specification | Value |
|---|---|
| Amperage | 110A |
| Poles | 3 |
| Voltage | 600VAC |
| Interrupt Rating | 25kA @ 480V · 18kA @ 600V (MARK 75: 75kA @ 240V) |
| Frame Size | F-Frame (150A Frame) |
| Mounting Type | Bolt-On |
| Trip Type | Thermal Magnetic |
| Trip Function | LI — Long-Time, Instantaneous |
| Wire Size | 14–1/0 AWG (Al/Cu) |
| Phase | 3-Phase |
| Standards | UL 489, CSA |
| Temperature Rating | 40°C |
Replaces: HFD3110
Westinghouse / Eaton HFB F-Frame MARK 75 600V 110A 3-pole circuit breaker. In stock at AllBreakerSales.com. Call (877) 611-0034 for same-day pricing. Genuine OEM parts, ships from US warehouse.
Brand: Westinghouse / Eaton | Series: HFB F-Frame MARK 75 600V | Catalog Number: HFB3110
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