Eaton / Cutler-Hammer HFB3125 Molded Case Circuit Breaker
- 125A
- 3 Pole
- Bolt-On
Quantity
Eaton / Cutler-Hammer HFB3125 - 125A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Engineered for commercial power distribution, the Eaton HFB3125 is a 3-pole, 125A molded case circuit breaker. It provides reliable thermal-magnetic protection for heavy-duty electrical systems. This F-frame breaker installs into Eaton Pow-R-Line C panelboards, as well as older Westinghouse panels and switchboards. It serves as an exact replacement for legacy installations and is superseded by the HFD3125 for newer applications. Rated for 65kAIC at 240VAC, it features fixed trip settings.Specifications
| Brand | Eaton / Cutler-Hammer |
|---|---|
| Part Number | HFB3125-R |
| Series | HFB |
| Amperage | 125A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600VAC, 250VDC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 25kA @ 480VAC, 18kA @ 600VAC, 10kA @ 250VDC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Eaton Pow-R-Line C Panelboards, Westinghouse Panelboards, Switchboards |
| Wire Gauge | 4 AWG-4/0 AWG (Cu/Al) |
| Max Wire | 4/0 AWG |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs |
| Standards | NEMA AB-1, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | High Interrupting Capacity, HACR Rated |
Product FAQs
7 answersWhat panelboards are compatible with the HFB3125 circuit breaker?
This F-Frame breaker is designed to mount in Eaton Pow-R-Line C panelboards, as well as legacy Westinghouse panelboards and switchboards that accept bolt-on F-Frame breakers.
Can the Eaton HFB3125 replace an older Westinghouse HFB3125?
Yes. Eaton acquired the Westinghouse distribution equipment business. The Eaton or Cutler-Hammer HFB3125 is a direct, exact replacement for the legacy Westinghouse HFB3125, maintaining the same physical dimensions and mounting footprint.
What is the difference between the FB3125 and the HFB3125?
The HFB3125 is the high-interrupting "Mark 75" version of the standard FB3125. While the standard FB3125 is typically rated at 14kAIC at 480VAC, the HFB3125 provides a higher 25kAIC rating at 480VAC for systems requiring greater fault protection.
What is the modern replacement for the HFB3125?
For newer applications or if the HFB3125 is unavailable, the Eaton HFD3125 is the direct, modern replacement. It shares the same F-Frame footprint and provides equivalent or higher interrupting ratings.
Can the HFB3125 be reverse fed?
Yes. Because this thermal-magnetic breaker does not have "Line" and "Load" markings, it is UL listed for reverse feed applications, allowing power to be supplied to either the top or bottom terminals.
Is the HFB3125 suitable for use with HVAC equipment?
Yes, the HFB3125 is HACR rated, meaning it is approved for use with heating, air conditioning, and refrigeration equipment that requires this specific certification.
What does the "Mark 75" designation mean on the HFB3125?
The Mark 75 designation indicates that the breaker belongs to Eaton's high-interrupting F-Frame series. It signifies that the breaker can safely interrupt up to 75,000 amps asymmetrical, or 65,000 amps symmetrical, at 240VAC. This provides significantly higher fault protection than standard FB breakers.
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