Cat Pump 8125 Motor 1Ph 115/220V 2.5Hp — 56HC TEFC Direct Drive Electric Motor
The 8125 is the single-phase workhorse behind a lot of small direct drive plunger pump packages. It puts out 2.5 horsepower at 1750 RPM on either 115 or 230 volts, so it drops into shops wired for standard household current as easily as it does into a 230V service. The 56HC frame with a 5/8" hollow shaft is what makes it a direct drive motor rather than a general purpose one — the pump slides onto the shaft and bolts to the flange, no belts, no sheaves, no guard to align. That keeps the whole assembly short, quiet, and about as low-maintenance as a pump drive gets.
Built as a totally enclosed fan cooled unit, the 8125 handles the damp, dusty, splash-prone corners where pumps usually live. It's a capacitor start design with a 1.15 service factor and a 104°F maximum ambient rating, drawing 20.8 amps on 115V or 10.4 amps on 230V. It runs at both 60 Hz and 50 Hz, which matters if you're building equipment for export or working with imported machinery. Note that thermal overload protection is manual reset and not built in, so a starter or overload device belongs in the circuit — most integrators wire one in as a matter of course.
Where does it end up? Car wash bays, reverse osmosis and water treatment skids, high-pressure misting and fogging systems, agricultural spraying, humidification, parts washing, and plenty of OEM machinery that needs a compact pressure source. Because it's electric, there are no exhaust fumes and it can be hard-wired for permanent stationary duty — a real advantage indoors, in food plants, and anywhere a gas engine simply isn't an option. Marine washdown is one application among many, not the whole story.
Key Features
- 2.5 HP single-phase motor purpose-built for direct drive plunger pump service
- Dual voltage 115/230V (110/220V) wiring for flexible installation
- 56HC frame with 5/8" hollow shaft — pump mounts directly, no belts or sheaves
- TEFC (totally enclosed fan cooled) construction for wet, dusty, and washdown environments
- Capacitor start design for strong breakaway torque under load
- 1.15 service factor for continuous duty headroom
- Dual frequency 60 Hz / 50 Hz operation
- No exhaust or fumes; can be hard-wired for permanent indoor installation
- Compact, low-vibration footprint compared with belt drive arrangements
Applications
- Car wash and vehicle wash bay pump packages
- Reverse osmosis, water treatment, and filtration skids
- High-pressure misting, fogging, and humidification systems
- Agricultural and horticultural spraying equipment
- Industrial parts washing and surface cleaning
- Machine tool coolant and process water delivery
- Dust suppression and evaporative cooling
- OEM pressure washer and pump unit builds
- General washdown duty, including marine and dockside use
Specifications
- Manufacturer Part Number: 8125
- Motor Type: Electric, direct drive pump motor
- Horsepower: 2.5 HP (2.2 kW)
- Phase: Single phase (1Ph)
- Voltage: 115/230V (110/220V)
- Full Load Amps: 20.8 A at 115V / 10.4 A at 230V
- Speed: 1750 RPM (nominal 1725 RPM)
- Frequency: 60 Hz / 50 Hz
- Frame: 56HC
- Enclosure: TEFC — totally enclosed fan cooled
- Shaft: 5/8" hollow shaft
- Start Type: Capacitor start
- Service Factor: 1.15
- Thermal Overload: Manual reset, not included
- Maximum Ambient Temperature: 104°F (40°C)
- Motor Weight: Approximately 52.9 lb
- Mounting: Direct drive flange mount to compatible plunger pumps
Frequently Asked Questions
Q: Does the 8125 come pre-wired for 115V or 230V?
A: It ships as a dual-voltage motor, and the connection is made in the terminal box according to the wiring diagram on the motor. Confirm which leads are tied together before energizing, because running a 115V-configured motor on 230V will damage it immediately.
Q: Do I need a separate motor starter or overload with this motor?
A: Yes. The thermal overload on the 8125 is manual reset and is not supplied with the motor, so a properly sized starter or overload protection device should be installed in the circuit ahead of it.
Q: What size circuit does it need on 115 volts?
A: At 20.8 full load amps on 115V, it needs a dedicated circuit sized per local electrical code — a standard 15 or 20 amp household receptacle circuit is generally not adequate. Many users wire it for 230V specifically to cut the current draw roughly in half.
Q: Can this motor be used outdoors?
A: The TEFC enclosure tolerates damp and dusty conditions, but the motor is not weatherproof. For outdoor installations it should be sheltered from direct rain and standing water, and the ambient temperature must stay at or below 104°F.
Q: What does the 5/8" hollow shaft mean for pump mounting?
A: The pump's own crankshaft inserts into the hollow motor shaft and the pump housing bolts to the 56HC flange, forming a single assembly. That eliminates coupling alignment and belt tensioning, but it also means the pump must be built for a 5/8" hollow shaft 56HC mount to fit.
CLRMarine
