Century BN51 2 HP two speed 230V 48Y frame thru bolt pool pump motorCentury 2 HP 2 Speed 230V 48 Frame Pool Pump Motor, BN51 In stock$43299
Century BN51 2 HP two speed 230V 48Y frame thru bolt pool pump motor
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Century 2 HP 2 Speed 230V 48 Frame Pool Pump Motor, BN51

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$43299
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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.
Full description and specifications ↓

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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.

From Pool School

Replace the Pool Pump Motor or the Whole Pump?The manufacturers' tests first, what each repair replaces, and the federal motor rule. Read How to Prime a Pool PumpFrom the breaker to a full pot, each manufacturer's time limit, and what to check when it won't catch prime. Read
Specifications
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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Customer reviews

Questions and answers

What people ask about this product, answered by our pool techs.

Is this motor 230V or 240V?
The listing calls it 230V and the motor data reads 240V. Both describe the same nominal residential service, so it goes on a 230/240V circuit. If your supply is 115V, this is not the motor.
What do the two speeds do for me?
Low speed at 1750 RPM turns the water over quietly and at a fraction of the power draw, which is where a pool should spend most of its filtering hours. High speed at 3450 RPM is there for vacuuming, backwashing and running a cleaner.
Will it fit my pump?
It is a 48Y frame thru bolt motor. Check the frame, horsepower, service factor and voltage on the nameplate of the motor you are replacing, because the wet end is built around a specific frame and the shaft has to match.
What does thru bolt mean?
It describes how the motor is assembled and mounted, with bolts running through the motor body. It is one of the standard 48 frame constructions, and it is worth confirming your existing motor is the same before ordering.
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