How to Read a Pool Motor Label


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This "How To" will provide an explanation of the stats and ratings listed on a pool pump motor label. When attempting to find a replacement pool motor not all of these ratings are necessary but it is good to know, just in case.

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Step by Step


Step 1

The model number is the easiest way to identify your pump motor replacement. Manufacturers like A.O. Smith do not have a set format for their model numbers. This is dependent upon the specific pump the motor is to be matched with. For example, an A.O. Smith motor that is compatible with Pentair brand pumps may have a model number of B853 or BN24, but an A.O. motor meant for a Hayward pump will have a model number of UST1102 or ST1152. On the motor label there may be a second model number listed, this number generally will begin with either a "C48", "C56", "K48" or "K56" followed by four to nine letters and numbers. An example of this style is C48L2N103B1. Not all manufacturers call their model number by that name, Century Electric refer to theirs as a “Part Number” which has its own unique format. A Century part number consists only of digits and is in the form of“x-xxxxxx-xx”. Extract the middle six digits from that part number and enter it into our search engine for an exact result. A motor model number of any of these varieties can be entered into INYO's product search engine and an exact match can be found.

Step 2

Serial Number (SN) - This number can identify where and when your motor was made it cannot help you track down the replacement. At best you can use this number to contact the manufacturer to narrow the search.

Step 3

Horsepower (HP) - This rating on your pump is the same as the horsepower your car because it is the measure of power output for your motor. For a residential pool pump, the range of HP is .5 to 3. The first thought for new pool owners replacing a motor is to think "Bigger is Better", that a more powerful motor leads to a better running or cleaner pool. This is not necessarily the case also you must take into consideration that a new impeller and possibly a new diffuser may need to be bought to accommodate the new motor. The added pressure may also overwhelm the filter system if it cannot handle the extra water surging through which may damage your filter or piping.

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Step 4

Service Factor (SF) - A full explanation of this rating would take pages but the short of it is that if you multiply the Horsepower by the Service Factor the result is the "Total HP" of your motor. SF for pumps broken into two categories, Up Rated and Full Rated. It is easy to determine which of these your pool pump motor falls into, if you label states the SF is 1.27 or below it Up Rated, anything above it is Full Rated.

Step 5

Frame (FR) - The point where the motor and wet end meet to become the pool pump is called the Flange. The end of the motor that connects to this flange can be shaped in several ways and this configuration is rated on the motor label under the category of Frame. The FR of the pump motor is generally one of four configurations (48Y, 56Y, 56J, 56C). The number "48" or "56" denotes diameter of the motor casing. The letter at the end tells you the shape of the connection, "Y" is square, or "C" and "J" that note a circle flange. As with a circle peg into a square hole a Y-frame will not hook into a C or J.

Step 6

Amps - When you take a look at your power bill and want to know why it is so high, look no further than this rating. The amps will be listed according to volts, Volts = 115/230, the amp rating will be listed respectively for example, 16.0/8.0. The lower the amps the bigger the savings. Your pump may have an energy efficient (EE) replacement motor available that can be substituted for a standard type. The EE and standard motors do not differ in their operation or installation but only in the amount of amps drawn, the EE model drawing a quarter to a third less.

Step 7

Revolutions Per Minute (RPM) - An RPM rating of 3450 is universal for residential single-speed pumps if you have a dual-speed this rating will be 3450/1725.

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Step 8

Phase (PH) - Denotes whether the motor operates on single-phase AC current or three phase AC current. Three phase motors are generally used for commercial purposes.

Step 9

Ambient Temperature (AMB) - Displaying the highest environmental temperature tolerance the motor can withstand, this rating is usually listed as 50 Degrees Celsius. Converted to Fahrenheit that comes to about 122 degrees which would not be a concern unless you live in the Sahara.

Step 10

Time - This denotes the time the motor can operate between shutoffs. Pool pump motors are listed as "CONT" for continuous, meaning the motor can run 24/7 without breaks. For normal operation of your pool this round the clock pumping is unnecessary. A six to eight hour run of your pump will keep the water clean and clear, as well as save you on the power bill.

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(1 to 13 of 13)

 Posted: 6/19/2022 

Us motor c55cxklz5010 please help find replacement.

InyoPools Product Specialist  Posted: 6/27/2022 

Please verify that model number because it does not appear valid in our system.

 Posted: 11/29/2021 

Hi- You indicate that the serial number can indicate information regarding when the pool pump was made, but your picture doesn't show this explanation or how the serial number might present this. Can you give more explanation about this?

InyoPools Product Specialist  Posted: 11/30/2021 

This guide shows you how to decipher the pool pump motor serial number code, How to Read a Century Pool Pump Motor Serial Number.

 Posted: 3/4/2020 

I have a customer with a century motor model # k48a89a04 could you help me find the direct replacement?

InyoPools Product Specialist  Posted: 3/9/2020 

Hello, I typed the part number k48a89a04 in our search at the top of the page, it resulted in a match to the Hayward Max-Flo II 1.5 HP 2-Speed Motor - SPX2710Z2M. If you have the Max-Flo II pump, the correct shaft seal needed to complete the installation is the SPX2700SA or the PS-3867

 Posted: 10/31/2018 

I have a 1 HP Hayward Pump for my inground swimming pool, which motor is the proper replacement?

InyoPools Product Specialist  Posted: 10/31/2018 

Hi EQ, Could you let us know the model of your Hayward Pump? Common models are the Hayward Super II, Super Pump and Max Flo. Also if you could supply amps, volts, service factor (SF) and frame of your motor.

 Posted: 10/31/2018 

I have a Hayward Super Pump with the following information on the label Service Factor (SF) 1.1, Volts 115/230, Amps 15.0/7.5, Frame 56J

Anonymous  Posted: 9/9/2019 

I need too know the impeller selection in this pump model c55CXHPG-4179

InyoPools Product Specialist  Posted: 9/12/2019 

Hello - that is a model/part number of a Marathon motor. Those motors can be mounted to dozens of different pup housings, and each of those housings has their own style of impeller. If you want to know the right impeller for your pump, look at the part number of your current impeller or find the model number of the pump housing. The former, being the easiest way to find the correct impeller.

 Posted: 9/12/2015 

Very condensed yet accurate and comprehensive explanation. Thanks!

 Posted: 6/23/2013 

very well presented and useful