Century B129 1.5 HP Pool Pump Motor – 56J Frame, 115/230V, Single Speed

The Century B129 1.5 HP Pool Pump Motor is a professional-grade replacement motor designed for compatible inground swimming pool and spa pumps. Featuring a 56J frame, threaded stainless steel shaft, and dual-voltage 115/230V operation, this single-speed motor provides dependable performance for residential pool circulation systems.

Manufactured by Century, formerly A.O. Smith, the B129 features a 1.30 service factor, providing 1.95 total horsepower. Its permanent split capacitor (PSC) design delivers reliable motor operation without a mechanical starting switch.

Designed for continuous-duty pool pump applications, the Century B129 is an excellent replacement for compatible Hayward, Jandy, Marlow, and other pool pump assemblies requiring a 56J threaded-shaft motor.

Product Features

• 1.5 HP Full-Rated Motor: Delivers 1.95 total horsepower with a 1.30 service factor.
• Dual Voltage: Operates on either 115V or 230V electrical systems when properly configured.
• 3450 RPM Single Speed: Provides consistent rotational speed for compatible pool pump applications.
• 56J Frame: Standard round-flange motor configuration with threaded shaft.
• Stainless Steel Shaft: Durable shaft construction designed for pool pump applications.
• Permanent Split Capacitor: Switchless PSC motor design for dependable operation.
• Automatic Thermal Protection: Built-in overload protection helps protect against excessive motor temperatures.
• Open Dripproof Enclosure: Designed for properly protected and ventilated equipment installations.
• Continuous-Duty Design: Built for regular swimming pool circulation applications.

Product Specifications

• Manufacturer: Century / Regal Rexnord
• Manufacturer Part Number: B129
• Motor Horsepower: 1.5 HP Full-Rated
• Service Factor: 1.30
• Total Horsepower: 1.95 THP
• Voltage: 115/230V AC
• Amperage: 18.4A at 115V / 9.2A at 230V (Service Factor Amps)
• Motor Speed: 3450 RPM
• Number of Speeds: Single Speed
• Frequency: 60 Hz
• Phase: Single Phase
• Frame: 56J / P56J
• Mounting: Round C-Face
• Shaft Type: Threaded
• Shaft Diameter: 5/8 Inch
• Shaft Thread: 7/16-20
• Rotation: Counterclockwise Viewed From Pump End
• Motor Design: Permanent Split Capacitor (PSC)
• Enclosure: Open Dripproof (ODP)
• Thermal Protection: Automatic Overload
• Insulation Class: B
• Duty: Continuous
• Approximate Overall Length: 13.5 Inches
• Motor Body Diameter: 6.5 Inches
• UPC: 786674011909
• Quantity: 1 Replacement Motor

Common Compatible Pump Applications

The Century B129 is used with select pool pump models requiring a 1.5 HP full-rated, 56J threaded-shaft motor.

• Hayward Super Pump SP1600 Series
• Hayward Super Pump SP1600X Series
• Hayward Super Pump SP2600 Series
• Hayward Super Pump SP2600X Series
• Select Jandy Pool Pumps
• Select Marlow Pool Pumps
• Other compatible 56J threaded-shaft pool pump assemblies

Important: Not every pump within these series uses the same horsepower or motor configuration. Confirm the original motor nameplate, total horsepower, frame, flange, and shaft requirements before ordering.

Motor Cross-Reference Numbers

• Century B129
• A.O. Smith B129
• Century 8-164304-24
• Century 164304
• Century ST1152 – Verify specifications before substitution

When to Replace Your Pool Pump Motor

A failing pool pump motor may exhibit several symptoms that indicate repair or replacement is necessary.

• Motor humming without starting
• Frequent thermal overload shutdowns
• Excessive motor bearing noise
• Motor overheating during normal operation
• Corrosion or water damage near the motor shaft
• Motor failing to operate despite proper electrical supply

These symptoms may also result from capacitor failure, damaged bearings, incorrect wiring, or problems within the pump wet end. Proper diagnosis is recommended before replacing the motor.

Installation and Replacement Information

1. Turn off the electrical circuit and verify that power is disconnected.
2. Confirm the replacement motor matches the original motor's electrical and mechanical specifications.
3. Drain the pump and separate the motor from the pump housing following the pump manufacturer's instructions.
4. Remove the existing impeller and mechanical shaft seal as required.
5. Install a new compatible mechanical shaft seal when replacing the motor.
6. Transfer the compatible pump components to the replacement motor.
7. Confirm that the motor voltage configuration matches the available electrical supply.
8. Complete electrical connections and grounding according to the manufacturer's instructions and applicable electrical codes.
9. Reassemble and prime the pump before starting.
10. Verify correct rotation, motor operation, water circulation, and absence of leaks.

Related Pool Pump Replacement Parts

When replacing a Century B129 motor, inspect the mechanical shaft seal and pump housing gaskets. Aqua Pool Supply offers the following related replacement parts for compatible Hayward Super Pump applications.

• Hayward SPX1600Z2 – Mechanical Pump Shaft Seal Assembly – Genuine Hayward replacement shaft seal for compatible Super Pump wet ends. Recommended when installing a replacement motor.
• Aladdin GO-KIT3 – Hayward Super Pump Seal & Gasket Repair Kit – Repair kit for compatible Hayward Super Pump 1600 and 2600 series applications.
• Jard 12715 – 25 MFD 370V Round Motor Run Capacitor – Related replacement run capacitor option. Verify the existing motor capacitor's rating and dimensions before ordering.

Additional Pool Pump Replacement Parts

Browse our pool pump replacement parts for additional impellers, diffusers, shaft seals, gaskets, and repair components.

Motor Replacement Considerations

Always compare the original motor's total horsepower (HP multiplied by service factor), mounting configuration, shaft style, and electrical specifications before selecting a replacement motor.

Many applications requiring replacement of a single-speed pool pump motor may be subject to federal, state, or local energy efficiency requirements. Verify that the replacement motor is permitted for the intended installation before purchasing.

Package Includes: One (1) Century B129 1.5 HP, 115/230V, Single-Speed Pool Pump Motor.

Note: Pump housing, impeller, diffuser, mechanical shaft seal, and wet-end components are not included. These components are sold separately unless otherwise specified.

Installation Safety: Pool pump motor installation involves electrical hazards. Installation should be performed by a qualified professional following applicable electrical codes and manufacturer instructions.