- Jul 8, 2011
- 41
Did you find a pump curve for this motor used with a pump? Is there a way to find out if it came as original equipment on anything? I'd like to see a curve for it.
Hayward Super Pump Head Curve
- Thread starter DaveAZ
- Start date
- May 3, 2007
- 16,834
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Re: Century B973 as new motor for hayward superpump?
The head curve of a wet end does not change with a change in motor. The only thing that is important when changing a motor is that it has a THP that is greater than or equal to the old motor THP and of course it is the correct frame.
The head curve of a wet end does not change with a change in motor. The only thing that is important when changing a motor is that it has a THP that is greater than or equal to the old motor THP and of course it is the correct frame.
- Jul 8, 2011
- 41
Re: Century B973 as new motor for hayward superpump?
So when a pump model shows four different curves, the difference in the curve is caused by the impeller difference, not the different motors used?
mas985 said:
So when a pump model shows four different curves, the difference in the curve is caused by the impeller difference, not the different motors used?
That is mostly true. As long as the motor is at least as large as the impeller was designed to work with, the head curve will be determined by the impeller. If the motor is too small there will be problems and the curve won't really match. If the motor is too large the extra motor size is essentially ignored and the head curve follows the impeller.
- May 3, 2007
- 16,834
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Head curves are primarily determined by the operational RPM, impeller, diffuser and volute. If a pump motor is properly loaded or even slightly underloaded it will run at 3450 RPM on high speed and 1725 RPM on low speed. If the motor is overload (i.e. motor too small), slip can increase and thus RPM decrease which in turn can change the head curve.
The wet end and motor are actually two separate machines which are connected by the motor shaft. The loading on the motor is determined by the wet end load and the wet end load is dependent on the speed of the impeller. So the motor is sized to the wet end load and if you have the same wet end, then when replacing the motor you want to make sure the new motor is rated to at least the same THP as the old motor. That way you are guarenteed the new motor will not be overloaded. It is ok to underload a motor but a motor cannot be overloaded without serious consequences.
The wet end and motor are actually two separate machines which are connected by the motor shaft. The loading on the motor is determined by the wet end load and the wet end load is dependent on the speed of the impeller. So the motor is sized to the wet end load and if you have the same wet end, then when replacing the motor you want to make sure the new motor is rated to at least the same THP as the old motor. That way you are guarenteed the new motor will not be overloaded. It is ok to underload a motor but a motor cannot be overloaded without serious consequences.
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