Century Pool Pump Motor, Threaded Shaft, 1HP 56J | UST1102
The Century (formerly A.O. Smith) UST1102 is one of the most popular replacement motors in the industry. This 1.0 Total Horsepower (THP) motor features a 56J Frame and a threaded shaft, designed as a seamless "drop-in" replacement for many high-head and medium-head pool pumps. Engineered with a high-service factor and an Open Drip-Proof (ODP) design, the UST1102 delivers consistent power while staying cool, ensuring your pool stays clear with minimal noise and maximum reliability.
Features
Universal 56J C-Flange: This industry-standard mounting style features a circular face with four bolt holes, making it compatible with a wide variety of pump housings from manufacturers like Hayward, Jacuzzi, and Sta-Rite.
Corrosion-Resistant Threaded Shaft: The 303 stainless steel threaded shaft provides a secure, rust-proof connection to your pump's impeller, preventing the "frozen" impellers common with lower-quality motors.
High-Service Factor (1.25): Though rated at 1.0 HP, the 1.25 service factor provides a 1.25 Total HP output. This allows the motor to handle high-resistance tasks, like vacuuming or running through a dirty filter, without straining.
Dual-Voltage Versatility: Designed to run on either 115V or 230V power. The motor features an easy-to-access terminal board for quick wiring adjustments during installation.
Automatic Thermal Protection: Equipped with an internal thermal overload protector that automatically shuts down the motor if it reaches unsafe temperatures, protecting the windings from permanent damage.
Quiet & Cool Operation: The ODP housing allows for efficient airflow across the internal components, extending the life of the bearings and insulation even in hot summer climates.
Specs
| Horsepower (HP) | 1.0 |
| Total Horsepower (THP) | 1.25 |
| Service Factor | 1.25 |
| Frame Size | 56J (C-Flange) |
| Shaft Type | Threaded (303 Stainless Steel) |
| Voltage | 115V / 230V (Dual Voltage) |
| Amps | 15.0 / 7.5 |
| Speed | 3450 RPM (Single Speed) |
| Model Number | UST1102 |
Notes
Common Pump Compatibility
The UST1102 is a direct motor replacement for many popular threaded-shaft pumps, including:
Hayward: Super Pump, Super II, MaxFlo, and NorthStar (standard-rated versions)
Sta-Rite: Dyna-Glas, Max-E-Glas
Jacuzzi: Magnum Series
Pentair: Various Challenger and WhisperFlo models (Check frame spec)
Important Installation Tip
Never Reuse an Old Seal: When installing a new motor, you should always install a new Mechanical Shaft Seal (sold separately). An old seal is prone to leaking, and even a tiny amount of water traveling down the shaft can destroy the front bearing of your brand-new motor, voiding your warranty.
