Century 2.5 HP Up Rated NorthStar Replacement Motor - USN1252



Part # USN1252

By Century Motors

  4.8 Average  



Part # USN1252

Warranty 1 Year

Alternate Part #'s 187939, 193223, 193689, 7-193689-03, SP1620Z1MNS, SP1620Z1MNSC, SPX1620Z1MNS, USN1252, 35-150-3290, AOS-60-6005, AOSUSN1252

Product Description

Uprated 2.5 HP motor; 3450 rpm, 208-230; 13.0 - 11.8 full load amps; 1.10 service factor; 56J frame

Note: NOT California Title 20 Compliant. 

California Title 20 Compliant Options:

Motor Dimensions Motor Dimensions
Motor Image Motor Image

Product Specifications

Motor Name:
2.5 HP USN1252 & SP1620Z1MNSC Replacement Pool Motor
2.5 HP
3450 RPM
208 - 230 V
13.0 - 11.8 amp
Service Factor:
Total HP:
2.75 HP
Stock #:
USN1252 or SP1620Z1MNSC
Dimension Letter:
14.60 in.
Commonly Used On:
Hayward Northstar Pump

?     Asked on 11/13/2020 by Leslie Hughes

Is SPX3215Z1MR an equivalent replacement for USN1252? If not can you help me understand any disadvantages please? Thanks!!

A  Answered on 11/13/2020 by InyoPools Product Specialist Hector F.

Hi Leslie, the correct replacement motor for the motor model SPX3215Z1MR is actually the 5112-257. The USN1252 is a round flange so would not bolt up to your pump. You will also need a Hayward Tristar seal kit when you replace your motor if you indeed have this pump model as the SPX3215Z1MR is typically used on the Hayward Tristar. We put together this Video on How to Replace a Pool Pump Motor which you may find helpful when you tackle this project.

  • Commented on 11/13/2020 by Product Owner

    I previously had the USN1252 and they exchanged it for the SPX3215Z1MR already. They did change the portion with the skimmer & basket and the motor, but it is all together much smaller than what i originally had. My insurance is paying to "put me whole" so I am wondering if i need them to redo this with the right model or if this is a reasonable/acceptable replacement. I really appreciate your input.

    • Commented on 2/18/2021 by InyoPools Product Specialist Hector F.

      Hi Leslie, essentially the SPX3215Z1MR motor is not as strong as the USN1252 however it may be that the licensed contractor that changed your pump out has calculated if you can go down in HP. There are a number of variables to consider when sizing a pool pump. Here is a guide that we put together called "How to Size a Pool Pump for Your In-Ground Pool" that may assist if you would like to go over your installer's calculations. 

?     Asked on 6/26/2017 by

How can I tell what hp pump this is if I can't read the label. Is the length different on the different hp?

A  Answered on 6/26/2017 by InyoPools Product Specialist Alex V.

Hello, Can you please provide the model number on the pump housing and/or a picture of the motor label? 

?     Asked on 1/19/2012 by Guest

I'm trying to replace the motor on my pool pump but all these numbers and abbreviations on the motor label are really confusing me. What do they mean?

A  Answered on 1/19/2012 by InyoPools Product Specialist Patrick P.

Replacing a pool pump motor is not as difficult as it seems. You can try looking here. If you need help figuring out what the information on your label means. If you are still having difficulty figuring it out you can call us at our toll free number or you can send us a photo of your motor label here.

?     Asked on 1/18/2012 by Guest

I'm trying to find a replacement motor for my pool pump but my model number doesn't match what you have listed as the model number. My model number begins with a C48 and yours begins with an SP. Please help.

A  Answered on 1/18/2012 by InyoPools Product Specialist Patrick P.

What we have listed on our chart pages is the pump model number. The model number you have will just identify the motor. If you look on the plastic housing on the pump there should be a sticker which will have the pump model number. You can usually find this by the discharge port on the pump. Once you locate it you can choose the correct replacement motor. Be certain to change the shaft seal and gaskets as needed. You can use our >How to guide if you need help. 

?     Asked on 1/12/2012 by Guest

Why should I purchase a Tune Up Kit?

A  Answered on 1/12/2012 by InyoPools Product Specialist Patrick P.

A Tune Up Kit includes all of the essential replacement seals and gaskets for the pump. The seals and gaskets should be replaced when installing a new motor on your pump. New seals will prevent the pump from leaking water or losing the prime. A Tune Up Kit will protect your motor and ensure that the pump is working efficiently.

?     Asked on 1/12/2012 by Guest

Why do I need to purchase a new shaft seal?

A  Answered on 1/12/2012 by InyoPools Product Specialist Patrick P.

We strongly recommend replacing the shaft seal. The purpose of a shaft seal is to prevent water from running down the shaft of the motor and into the motor housing. Water will damage the bearings and cause the motor to fail. A new shaft seal should be installed whenever a motor is replaced. The motor manufacturer can deny the warranty if the motor fails to due to water damage from a faulty shaft seal. To find your shaft seal you will need to visit our Pool Pump Parts Page or the Spa Pump Parts Page and select your make and model.

?     Asked on 1/11/2012 by Guest

What is Service Factor?

A  Answered on 1/11/2012 by InyoPools Product Specialist Patrick P.

Service Factor(SF) is a multiplier that when multiplied by the horsepower of the motor indicates the total permissible horsepower loading that may be carried when the motor is operating at rated voltage and frequency. The most important thing to remember when replacing a motor is that the replacement motor's horsepower times its service factor must be equal to or greater than the original motor's horsepower times its service factor. The Service Factor rating can be found on the motor label. See Step 4 of our How to Read a Pool Motor Label guide.


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