Time to change the motor...

Jump to latest Follow Reply
S

Sminor

0
Jul 4, 2011
137
Perrysburg, OH
So finally got the pool opened after diy liner install and found my pump (which was loud last year) is now very loud! Last weekend I spent a few hours determined to rebuild it. I failed! I got it apart but broke three long bolts that hold the motor case together - they were very rusty. The back bearing wasn't bad at all. I couldn't access the front bearing as the two little bolts that hold it behind the faceplate would not budge! They are also very rusty and now stripped - of course! I gave up and put it back together. It still runs but it's really loud!

Therefore, I'm looking into new motors. I inherited all this stuff about 5 years when I got the house and it appears everything is original since install in 1999. I have a hayward max-flow pump. Wet end looks pretty good - installed new seal when I had it apart this weekend. The motor is magnatek 1 hp with a SF of 1.0, 3450 rpm, threaded shaft, yada yada, all pretty standard... Surprisingly the best deals I see for motors are on Amazon. The one I'm looking at matches everything but says it has a SF of 1.1. Does this matter? I've read up a bit on here and it sounds like SF doesn't really matter and has more to do with marketing...

Any advice would be appreciated before I get this motor ordered.

Thanks!
 
I would like to go 2 speed but not in the budget this year after new liner. Also looks like I may need a new cartridge filter as well - it's developing hairline cracks in the housing and currently has some major leakage. I'm thinking cheap new motor this year (prices I see are between $150-200) and upgrade next year. Unless a 2 speed isn't much more expensive... I haven't looked into pricing them much just assumed they were much more $. Would I need to change anything else if I go 2-speed? Different Impeller?
 
That would work, although you have a smaller impeller so should be able to get a 1HP 2 speed for cheaper.

You can use the larger motor on your impeller no problem. You will just need to add a switch to select speeds, a household 3 way light switch works well. And a shaft seal which I think you already got.
 
No, because the low speed is designed to work like that.
Putting a larger impeller on a smaller motor would put too much resistance on the motor and make it overheat. Electric motors run at a set RPM, so the motor will run at that speed regardless of the resistance which is why they burn up.

A smaller impeller on a larger motor will still run at the same speed, but with less resistance so lower here and power usage would be needed.

A 1HP impeller on a 1.5HP motor will use a very similar amount of power to that of a 1HP motor on the same impeller.
I just though you might be able to get a 1HP motor for less than the 1.5HP motor ... if not, the 1.5 will work fine.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Here's the bicycle analogy....

Imagine you're riding your 10 speed and you have to maintain 75 rpm. Set the gears to the lowest (easiest gear) and pump away at 75 rpm. Perceived effort is pretty low. Easy even. Now crank it up to the highest gear and hold 75 rpm. Much much harder. In this case, you (the pedaler) are the motor, and changing to the higher gear is equivalent to putting on a bigger impeller. With the same size motor but a bigger impeller (same size legs but "harder" gear ratio), you're gonna get burned up pretty quick.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply