
Century 2 HP 2 Speed 230V 48 Frame Pool Pump Motor, BN51
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Quick overview
- Two speed Runs 1750 RPM on low and 3450 RPM on high, so filtering can happen on the quiet, cheap speed.
- 2 HP at 230V Drawing 10.5 amps on high and 2.6 amps on low.
- 48Y frame, thru bolt The 48Y frame in thru bolt construction, which is how it fastens to the pump wet end.
- 1.0 service factor A full rated 2 HP motor at a service factor of 1.0.
- Genuine Century Century part number BN51, the replacement motor rather than a rewound unit.
- Match before you order Compare frame, horsepower, service factor, speed and voltage on your old motor nameplate before ordering, because the wet end has to match the frame.
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Frequently bought together

Century 2 HP 2 Speed 230V 48 Frame Pool Pump Motor, BN51

Century 1-1/2 HP 3450 RPM 56Y Frame Square Flange Pool Pump Motor, 115/230V, B2854V1

Century VGreen Evo Variable Speed 1.65 THP Square Flange Pool Pump Motor, 230/115 V, 48Y Frame, EVQ165

Century 1.65 HP Square Flange Pool and Spa Pump Motor, 3450 RPM 48Y, Threaded Shaft, HSQ165
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Product details
The Century BN51 is a 2 HP two speed replacement pool pump motor for 230V service, built on the 48Y frame in thru bolt construction. It runs 1750 RPM on low and 3450 RPM on high at a 1.0 service factor, drawing 10.5 amps on high and 2.6 amps on low.
Why two speed
Water only has to move slowly to be filtered. A two speed motor lets the pump spend most of its hours on low, where it is quieter and draws a small fraction of the power, and switch to high only when you need the flow: vacuuming, backwashing, or running a pressure side cleaner. On a pool that runs many hours a day, that difference is the whole reason two speed motors exist.
Making sure it fits
Motors are matched to the wet end by frame. Read the nameplate on the motor that is coming off and check the frame, the horsepower, the service factor, the speed count and the voltage against this one. Note that the data on this motor appears both as 230V and as 240V, which is the same nominal service, but a 115V pump is a different motor entirely.
Installation
A two speed motor needs to be wired for two speeds, which means the timer or controller has to be able to switch it. If your existing setup only ever ran a single speed motor, plan the control side along with the motor.
| Brand | Century |
|---|---|
| Manufacturer part number | BN51 |
| UPC | 786674014443 |
| Type | Replacement pool pump motor |
| Horsepower | 2 HP |
| Speeds | 2 speed |
| Voltage | 230V |
| Voltage stated in the motor data | 240V |
| Amps | 10.5/2.6 |
| RPM | 1750/3450 |
| Service factor | 1.0 |
| Frame | 48Y |
| Construction | Thru bolt |
| Shipping weight | 28.9 lb |
| Ships | Parcel |
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Questions and answers
What people ask about this product, answered by our pool techs.
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