Product Overview
Restore dependable performance to your swimming pool pump with the Century B129 1.5 HP Pool Pump Motor. Designed as a professional-grade replacement motor for compatible in-ground pool pumps, the B129 combines a durable 56J/P56J frame, single-speed 3450 RPM operation, and flexible 115/230V dual-voltage capability.
The Century B129 is a 1.5 HP full-rated motor with a 1.30 service factor, producing approximately 1.95 Total Horsepower (THP). This is an important specification when selecting a replacement motor because horsepower alone should not be used to determine compatibility. Always compare the horsepower, service factor, total horsepower, voltage, frame style, shaft configuration, and speed of your existing motor before purchasing.
Built for demanding pool and spa environments, the B129 features a threaded stainless-steel shaft, ball bearings, thermal protection, and an open drip-proof enclosure. Its permanent split capacitor design provides reliable single-speed operation for pool circulation and filtration applications.
Whether replacing a failed, noisy, overheating, or worn-out pool pump motor, the Century B129 provides a dependable replacement solution without requiring replacement of the complete pump when the existing pump housing and wet end remain serviceable.
Key Features
- 1.5 HP Full-Rated Motor – Designed for compatible residential swimming pool pump applications.
- 1.95 Total Horsepower – 1.5 HP × 1.30 service factor.
- Dual Voltage – Configurable for either 115V or 230V electrical service.
- 3450 RPM – Single-speed operation for consistent pool water circulation.
- 56J / P56J Frame – Common pool pump motor frame with threaded shaft configuration.
- Single Phase – Designed for standard single-phase pool equipment electrical systems.
- Permanent Split Capacitor Motor – Provides dependable single-speed operation.
- Threaded Stainless-Steel Shaft – Designed for pool pump impeller installation and corrosion resistance.
- Thermal Protection – Helps protect the motor from damaging operating temperatures.
- Continuous Duty – Engineered for extended pool circulation applications.
- Open Drip-Proof Design – Standard construction for pool and spa pump motor installations.
- Century Quality – Century is a long-established manufacturer of replacement pool and spa pump motors.
Technical Specifications
| Specification | Details |
|---|---|
| Manufacturer | Century |
| Model / Part Number | B129 |
| Motor Type | Pool & Spa Pump Motor |
| Horsepower | 1.5 HP |
| Service Factor | 1.30 |
| Total Horsepower (THP) | 1.95 HP |
| Voltage | 115/230V |
| Phase | Single Phase |
| Frequency | 60 Hz |
| Speed | Single Speed |
| RPM | 3450 RPM |
| Frame | P56J / 56J |
| Full Load Amps | 18.4A @ 115V / 9.2A @ 230V |
| Enclosure | Open Drip Proof |
| Duty | Continuous |
| Motor Type | Permanent Split Capacitor |
| Thermal Protection | Yes |
| Rotation | Counterclockwise Viewed From Pump End |
| Mounting | Round |
| Motor Orientation | Horizontal |
| Shaft Diameter | 5/8 in. |
| Shaft Type | Threaded |
| Insulation Class | Class B |
| Ambient Rating | 50°C |
| Application | Compatible Pool & Spa Pumps |
Replacement Motor Compatibility
The Century B129 is designed for pool pumps that require a 1.5 HP full-rated, 1.30 service factor, 56J-frame, threaded-shaft motor.
When replacing an existing pool pump motor, do not select a replacement based only on the stated horsepower.
Before Ordering, Verify:
- Existing motor horsepower
- Service factor
- Total horsepower
- 56J/P56J frame
- Threaded shaft configuration
- 3450 RPM speed
- Single-phase electrical supply
- 115V or 230V operating voltage
- Pump manufacturer requirements
Why Total Horsepower Matters
The B129 is rated at:
1.5 HP × 1.30 Service Factor = 1.95 Total Horsepower
Your replacement motor's total horsepower should meet the requirements of the pump's impeller and original motor configuration. Installing an undersized motor can cause overheating, nuisance shutdowns, reduced motor life, or premature failure.
Ideal For
The Century B129 is an excellent option for:
- Replacing a failed pool pump motor
- Rebuilding an otherwise serviceable pool pump
- Residential in-ground swimming pool pumps
- Pool filtration and circulation systems
- Compatible 56J-frame pump assemblies
- Pool service technicians and equipment repair professionals
Installation Notes
Professional installation is recommended.
The motor must be configured for the correct incoming voltage before operation. Always disconnect electrical power at the breaker before servicing pool equipment and follow applicable local electrical codes.
When replacing a pool pump motor, it is strongly recommended to replace the pump shaft seal at the same time. Reusing an old shaft seal can allow water to leak into the new motor and cause premature bearing or motor failure.
Pump shaft seals, O-rings, gaskets, impellers, and other pump-specific components are sold separately unless specifically stated otherwise.
What's Included
- (1) Century B129 1.5 HP Pool Pump Motor
Pump housing, impeller, diffuser, shaft seal, O-rings, gaskets, wiring, and other installation components are not included unless otherwise specified.
Frequently Asked Questions
Is the Century B129 a 1.5 HP motor?
Yes. The B129 is rated at 1.5 HP with a 1.30 service factor, giving it approximately 1.95 Total Horsepower.
Is the B129 a single-speed or variable-speed motor?
The Century B129 is a single-speed motor operating at approximately 3450 RPM. It is not a variable-speed motor.
Can the Century B129 operate on 115V?
Yes. The B129 is a dual-voltage 115/230V motor and can be configured for either voltage when properly wired.
What frame is the Century B129?
The B129 uses a 56J/P56J pool pump motor frame with a threaded shaft.
What is the service factor of the B129?
The Century B129 has a 1.30 service factor.
What is the total horsepower of the Century B129?
The motor's approximate total horsepower is:
1.5 HP × 1.30 SF = 1.95 THP
Should I replace the shaft seal when installing a new motor?
Yes. Installing a new pump-specific shaft seal when replacing a motor is strongly recommended. A leaking or reused shaft seal can allow pool water into the motor and cause premature motor or bearing failure.
Will the B129 fit my pool pump?
It may fit many pumps designed around a 56J threaded-shaft motor, but compatibility should be confirmed using the original motor specifications and pump model. Match the frame, total horsepower, voltage, speed, shaft style, and mounting configuration before ordering.
Does this listing include the complete pool pump?
No. The B129 is the replacement electric motor only. The pump wet end, housing, impeller, diffuser, seals, plumbing connections, and other components are not included.