Century (A.O. Smith) 2.5 HP Up Rate Motor, Square Flange 48Y Frame, Single Speed - Model USQ1252



Part # USQ1252

By Century Motors

  4.67 Average  



Part # USQ1252

Warranty 1 Year

Alternate Part #'s 11804, 13280, 5KCR48UN2496X, A100G5L, A100G5LL, AE100G5LL, B840, B840SE, C1284, K48A03A24, K48N2EC11A1, K48N2P102A2, K48N2P102A3, K48N2P103, K48N2PA102A1, K48N2PA102A3, K48N2PA105, K48N2PA105A2, K48N2PA105C5, SQH25UP1, SQH25UP1E, USQ1252, V13280, AOS-60-5232, AOSUSQ1252

Product Description

Voltage 115/230, 230V = 11.2, Single Speed, Square Flange, RPM = 3450, Threaded Shaft, Frame = 48Y Used on the following models: Sta-Rite Max-E-Glas, Max-E-Glas II, Dura-Glas, Dura-Glas II, Dyna-Glas, Dyna-Max Pentair Whisperflow, Pinnacle and Anthony AR2 Series.

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 USQ1252 Replacement Pool Motor
2.5 HP
3450 RPM
230 V
11.2 amp
Service Factor:
Total HP:
2.5 HP
Stock #:
Overload Protector:
Dimension Letter:
13 - 7/8 in.
Commonly Used On:
Sta-Rite Max-E-Glas, Max-E-Glas II, Dura-Glas, Dura-Glas II, Dyna-Glas, Dyna-Max Pentair Whisperflow, Pinnacle and Anthony AR2 Series.

?     Asked on 5/31/2022by John Lovera

I have a Pentair 25LTHH. Motor # K48N2EC11A1. I need a motor and seal kit. What are the part numbers I need to order?

A  Answered on 5/31/2022 by InyoPools Product Specialist Craig C.

Hello John.  The Century 2.5 HP Square Flange 48Y Up Rate Motor - USQ1252 is the replacement motor for the model K48N2EC11A1.  The Pump Shaft Seal 5/8" PSR-100 is the shaft seal for the Pentair/Berkeley LTHH Series Self Priming Centrifugal Pump.  Attached please find the Pentair/Berkeley LTHH Series  Installation/Operation/Parts Manual for reference.

?     Asked on 5/9/2022by Bill Bsha

I have a sta-rite 2.5hp max-e-pro P6EAA6G-208L. Will this replace my motor????

A  Answered on 5/9/2022 by InyoPools Product Specialist Craig C.

Hello Bill.  The Century 2.5 HP Square Flange 48Y Up Rate Motor - USQ1252 is a compatible motor replacement for the Sta-Rite Pool Pump model P6EAA6G-208L.  The Tune Up Kit Sta-Rite Max-E-Pro (Pre February 2015) - GOKIT79 contains the seals and gaskets necessary to complete the motor change. 

?     Asked on 3/1/2020by Val

re. Century USQ1252 K48N2PA105C5 I am trying to replace the bearings and can't seem to find the correct part numbers. The front bearing is a different size from the rear bearing. Can you help me out with the part numbers? Do you carry them or should I purchase them locally or on line from a bearing supplier. What is the cost? Thanks.

A  Answered on 3/2/2020 by InyoPools Product Specialist Lennox H.

Hi, Val. The USQ1252 motor uses (1) 6204-2RS (Shaft End) and (1) 62032RS (Opposite Shaft End). 

?     Asked on 5/28/2019by Inyo Visitor

what is the seal kit part number for this motor

A  Answered on 5/28/2019 by InyoPools Product Specialist Patrick P.

To determine the proper seal kit we will need to know your pump make and model information, common pump names would be Pentair Whisperflo, Pentair Challenger, Jandy Stealth, etc.. To supply this information click the reply link below, also if you could send a few photos those are always helpful as well. If you send photos then take a close up shot of the motor label as well as a wide shot of the complete pump to include the pipes going in and out of the pump. To supply photos simply click the reply link below and upload your photos. Once we get any of this information we can make the proper recommendation.

?     Asked on 6/3/2017by Mo

What is the part number for the shaft seal for USQ 1252 pool pump. Mine seems to have a larger diameter that fits over a shaft on the the impeller.

A  Answered on 6/3/2017 by InyoPools Product Specialist Patrick P.

Hi Mo, We would need to know the make and model of your pump, could you reply with information or a photo showing a wide shot of your pump including where the plumbing goes in and out. Common pump names that this motor works on are Pentair, Sta-Rite, Jandy, etc..

?     Asked on 5/24/2017by Inyo Visitor

Hello, I have a Pentek AE100GLL motor for my sprinkler pump and I think the ball bearings are stuck. Will this motor be a good replacement for my current.

A  Answered on 5/24/2017 by InyoPools Product Specialist Hector F.

We technically do not provide support regarding sprinkler pumps but this motor does cross reference as the USQ1202.

?     Asked on 3/22/2017by Harry

This looks like the motor I need for my Cal Spa Dyna Max Pump. But the one I need to replace is two Speed. Does it come in two speed also ?

A  Answered on 3/22/2017 by InyoPools Product Specialist Scott W.

The 2 speed equivalent to the USQ1252 is part number B984 and the shaft seal to complete your motor install is part number 5057-07.

?     Asked on 1/3/2017by Steve

I Have a Starite Max E Pro P6E6G-208L. Motor Model number K48N2PA105 2.0 SF 1.3. I think the USQ1202 dimensions will work better( so it doesn't change installed hight to pump housing) but that motor may be slightly under powered at 2.0 SF 1.1 Are both of these Energy efficient rated?

A  Answered on 1/4/2017 by InyoPools Product Specialist Adam Y.

Good morning Steve, You need a A.O. Smith 2 H.P Square Flange Full Rate Motor - SQ1202 It is not EE but at 230v it is only running 11amps. The only EE that will work is a 56Y frame which means the motor will be thicker. But it's running 10.2 -11amps so there is not much of a difference energy wise. that would be a 2 HP Motor EE - Full Rate (B843, B2843)

?     Asked on 10/6/2016by Takopoke

I need a new motor for a 5 year old Hayward Tristar SP3220X25 2-1/2hp pump. Would this pump fit and is there a salt water tune up kit for it also. TY

A  Answered on 10/11/2016 by InyoPools Product Specialist Lennox H.

Hi, Takopoke. Yes, this motor (USQ1252) will fit the Hayward TriStar SP3220X25 pump. There is not a tune up kit for this pump, the seals will have to be purchased separately. You can locate all the parts on the Hayward TriStar Pump Parts page.

?     Asked on 3/7/2016by Robert

Thanks for the quick response about which motor is appropriate for the Jandy FHPM2.5. You mentioned that either the 56Y or 48Y will work, with the difference being the barrel motor size being 1" different. Is there any benefit of one over the other? Also, which Shaft Seal or Tune-Up kit would be used for either (or both) of the motors (USQ1252 and B840)? Thanks again.

A  Answered on 3/9/2016 by InyoPools Product Specialist Lennox H.

Hi Robert, There is not benefit of one over the other, their is not a tune up kit available for this pump. You can find the replacement shaft seal and o-rings needed for your pump via the Jandy Flo Pro Pump FHPM Parts.

?     Asked on 3/7/2016by Robert

I've got a Jandy Flopro 2.5 HP pump which is about 5 years old. The motor was replaced about 2 years ago with a USQ1252, which is a 48Y Frame Square Flange model. Now the motor has gone bad again. When I looked at the user's manual, however, it says that an appropriate replacement motor is a B840 56Y model. Now I'm really confused - do I need a USQ1252 or a B840? Thanks for your advice!

A  Answered on 3/7/2016 by InyoPools Product Specialist Andy O.

Hello Robert, You can use either motor. The USQ1252 A.O. Smith 2 1/2 H.P Square Flange Up Rate Motor (USQ1252, C1284, B884) and the B840 A.O. Smith 2.5 HP, 56Y Frame, Up-Rate Motor (B840, B2840) will both fit. The only difference is the USQ1252 is a 48y and the barrel of the motor is 1" in diameter smaller than the 56y. But both will bolt up the same and work the same.

?     Asked on 6/17/2015by Adrian V

Hi I'm trying to repair a USQ1252 motor, the problem is that the capacitor has gone bad but I can't identify the range of microfarads of the capacitor, can someone tell me what capacity should the capacitor be for this motor????

A  Answered on 6/18/2015 by InyoPools Product Specialist Robert M.

Hello Adrian - The run capacitor is 370v and 30 MFD. The start capacitor is 250v and 36-43 MFD.

?     Asked on 1/19/2012by 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 1/12/2012by 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 1/12/2012by 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 1/11/2012by 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.


Est. Repair Time

1 to 2 hrs

Tools Needed

Screwdriver, Pliers, Socket Set, Wrench Set

My pool pump was making loud sounds and eventually it seized up.

Written on 4/21/2022 by Guest

Disconnected power at the breaker.
Removed the power from pump and disconnected the pump from the housing. I noticed that the impeller was broken. Wasn’t obvious to me at first, but I quickly reorder a new impeller. I will say YouTube is your friend. Numerous videos helped me get it installed.

With a little patience, I had it back together in less than 2hrs.

Were these instructions helpful? 


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