Is pool pump motor with SF lower than original ok to be replced?

Hello lynlynch:

I'm going to defer this comment to you as I have very little experience with swimming pool pump motors. Truthfully I don't know that I have ever run into a motor with a service factor of 1.6.

However it has been my experience that when I run into a motor with unusual specifications that it generally is an OEM listing a motor that they know nobody else makes, and of course it's a premium price.

Of course frame sizes and shaft sizes must be considered, but in the past I generally upsize the motor to a larger standard industrial motor. With a service factor of 1.2 or so. In this case if it is available with the correct frame size and connections, I would probably use a 1 1/2 horsepower motor.

Of course sometimes this is not possible due to unusual shaft sizes etc., but the cost savings can be quite significant , some of these unique OEM motors costs three or four times the price of an standard industrial motor.

PS: it's pretty easy to order a large number of units with a custom tag on it and triple the price, course I think it's unethical, but it's not unusual.

Lynch and others ---- Let me give you more info Im an older person that has a home owners insurance policy on my pool pump and the insurance company sent out 2 separate non electrical people that want to put a generic energy efficient motor to replace the energy efficient motor which is part of the pump. The manufacturer Pentair Pool Supplies, and the company that makes the motors for Pentair Pool Pumps state that you just can't replace a lesser Output Motor (per formula listed above in original message) or you will damage the impellar of the pump and the pump will not be as efficient etc. What I would like you to see is serial # below QC1102 and this would actually be the replacement motor for my pump. Based on the new part Pentair recommends (see below) and see the uprate HP and uprate SF etc. and knowing I don't care about price I just want the pump to be just like it was when I first got it, then would a generic made motor 1HP with a SF 1.4 be exactly the same as compared to exactly following the manufacture recommendation of 1HP with a 1.65SF or maybe they don't make the 1HP and 1.65SF and Pentair is saying its ok to use the 1.5Hp with the 1.1SF which as a totally unknowledgeable brain for electronics (me) it sounds like you are saying that this 1.5HP with the 1.1SF is a match. So in summary if I do understand then the generic 1HP 1.4SF is NOT appropriate. Am I sort of understanding you? Please understand I'm a teacher/physician/reseacher and as with all people we really ask for nothing more than to at least be given our options, and hopefully all the options are spelled out for us, and then hopefully we can make a choice which we hope is the absolute best choice based on many factors. In other words I want what is recommened in this case by manufacture and by rules (i.e. per above OUTPUT statement in original message). My problem is uneducated pool people are stating don't worry the HP1/SF1.4 is fine and I feel it isn't but I need in lay persons terms to be able to explain why the generic HP1/SF1.4 motor will not be proper as a replacement for my pump. Will the GPM(gallons per minute) be the same, will the efficiency be the same and yes the HP1/SF1.4 is also a energy efficient motor but at $88.oo(HP1/SF1.4) vs. approximately $250.00(HP1/SF1.65) there must be a difference and of course insurance companies want to save money. So I'm very sorry to bother you again but I would love to have you help me here. Thanks alot!!!!!

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Lynlynch Your answer makes sense but when your talking about a pool pump you can't just change the flow which is why the service factor I beleive is important in this case because stuff gets caught around the impeller or in the leef basket and the motor has to try to increase to a maximum level and if this need draws more amps then you can't and shouldn't be required to change the flow when they make a motor that with an increased SF will be sufficient. Please see the comment above from another responder and Id like to know your answer.

I do agree with Lynlynch I work for Facilities of a City and you will be quite safe with a lowerr Service Factor, some of my pools have a SF of 1.15 up to and including 1.50 and nothing higher. The pools and hot tubs range from 30 to 100 man hot tubs to Olympic Size Swimming pools. They also range in voltage from 110 to 230 single phase to 575 (600) 3 phase. These motors have been working 24/7 for years, but every 3 years for our maintence prevention we ohm, meger and change bearings on the motors.

SF (Service Factor)

A measure of the reserve margin built into the a motor.

Motors rated over 1.0 SF

Have more than normal margin.

and are used where unusual conditions such as

occasional high or low voltage

Momentary overloads etc

are likely to occur

as quoted from Grainger book

What is the info on the name plate on the existing motor

do you have it