Pump/Impeller Matching

[srsn1p3r]

Hello, Everyone

I would love to get some feedback on a motor swap I am being asked by a customer to complete. They had purchased a 1hp motor and are wanting me to install it on an impeller that is rated for 1.5, my understanding is that this would cause the motor to burn up. Are there any downsized aside from efficiency to oversizing it? Should I just match it exactly.

Thanks!

 

[ajw22]

Welcome to TFP.

What model pump, impeller p/n, and model motor are we discussing?

@JamesW

 

[JamesW]

They had purchased a 1hp motor and are wanting me to install it on an impeller that is rated for 1.5, my understanding is that this would cause the motor to burn up.

The total hp of the impeller needs to be the same as or lower than the motor.

 

[JamesW]

Note that the Impeller "Rating" does not correspond to the total HP required, so you really need to know the Total HP of the Pump and then match the motor.

For example, a "1 HP" impeller might take 1.65 hp.

Getting rid of "Service Factor" for motors.

Does service factor have any value? In my opinion, it has no value. In fact, I think that it only causes problems and confusion. The only number that really matters is the Total HP of the motor. Motor makers make two identical motors and label one as 1 hp with a 1.65 service factor and the...

www.troublefreepool.com

 

[JamesW]

This chart shows you what impeller each pump model number takes.

For example, the Impeller with a part number of 073128 is listed as a 1 hp impeller, but it really takes a total hp of 1.65, which is confusing.

The "1.5 hp" actually takes 2.2 total hp.

If you put a 1 hp motor on a 2.2 hp impeller, the motor will quickly burn up.

The below chart shows the total hp that each impeller takes.

Impeller......Total HP.

073126.........0.95
073127.........1.25
073128.........1.65
073129.........2.20
073130.........2.60
073131.........3.45

The total hp is the rated hp x the service factor.

A 1.0 hp motor with a service factor of 1.65 is the same as a 1.5 hp motor with a service factor of 1.1.

A 1.0 hp motor with a service factor of 1.65 is called a "full rated" motor.

A 1.5 hp motor with a service factor of 1.1 is called an "up-rated" motor.

They are both the exact same motor. They both have a total of 1.65 hp.

So, it's confusing to see one listed as 1 hp and the other listed as 1.5 hp.

The key is the total hp, which is what really matters.

The WF-26 model WhisperFlo takes a 073128 impeller, which requires 1.65 total hp.

Impeller...........Total HP required.
SPX2600C............0.60
SPX2605C............0.75
SPX2607C............1.10
SPX2610C............1.50
SPX2615C............2.00

 

[JamesW]

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