Waterfall motor replacement

[gbrenham]

I currently have a Hayward Super II Pump (I think - label long gone) being pushed by a A.O. Smith Century Centurion motor (Model: B128, Type: CX, FR: U56J, HP: 1.0, HZ:60 ,RPM: 3450 , Volts: 230/115, Amps: 6.0/12.0). I haven't run the waterfall in probably 3 years and the motor on the pump needs replacing. Saw the one below and want your opinions. We were thinking the old 1 HP was pushing too much water through the waterfall anyway and one reason I was looking at the 3/4 HP.

Bluffton B1321 0.75 HP Up Rated Single Speed Threaded Replacement Pool Motor

If this isn't a viable alternative, is there a cheap motor you suggest that would fit?

 

[ajw22]

@JamesW thoughts?

 

[kadavis]

If you go with a smaller motor you will need to also change impeller

 

[anotherpyr]

The SF on the existing motor appears to be 1.4 (from google) which would actually make it a 1.4 hp up rated or 1 hp full rated motor. I didn’t see the SF on the blufton but I suspect it’s only 1 making it an up rated .75 at that, so you’d see a big difference. The other issue is motor diameter. The blufton appears smaller and would require a mounting bracket adapter to support the weight of the motor otherwise it can pinch the housing gasket causing the pump to leak.

Also the blufton motor description states for above ground pools and the super pump II was an in ground pool pump I thought.

As mentioned you’d need to replace the impeller too as the smaller motor would struggle trying to turn it at speed.

 

[gbrenham]

Noted on the impeller. Yes, this is an in-ground pool. Guess I missed the Bluffton as an above ground motor, but it's just a motor - other than the impeller, who cares?

I guess the bracket and such is one reason most say stick with the same model.

Just trying to be frugal (cheap!), as I see used motors on Letgo and other marketplaces and wonder if they would fit. Would a Pentair work on a Hayward Super II Pump?

 

[gbrenham]

Think I might be getting this whole horsepower vs. service factor vs. total horsepower.

According to the recommendations, I don't really want to replace the diffuser and impeller, so I should stick with the same (i.e. equal) motor. To find an equal motor, I have to use the equation HPxSF to get to THP and then match THP on various motors (plus flange type and frame size)

Current:
A.O. Smith
HP=1
SF=1.4
THP=1.4

Pentair (See post above)
HP=.75
SF=.94
THP=.705

So this motor would NOT work. Correct?

Am I on the right track?

 

[anotherpyr]

The description for the blufton I found had the above ground statement in it. Not sure what would be different about the motor.

The flange has to match in order to bolt on. From the parts diagram Hayward | Super II Full Rated Pump | Replacement Parts Diagram the impeller would change from the 1hp to a 1/2 hp impeller. Both use the same diffuser and impeller ring if yours has that.

A simple way to know if a used pump motor would work is to look up replacement motors for the pump it came off of and see if they are also listed as replacements for the super pump 2 you have. If you can find the adapter shown in the parts diagram then that would allow you go with one of the smaller diameter motors sold for a super pump 2. When I went looking for one for my pump (not a super pump 2) I found that they stopped making the adapter and just made two different brackets now.

So to answer your question, no. You’d want to replace the impeller with the 1/2 hp one for the motor you were looking at. And yes THP is what’s important. The original would be a 1hp full rated, and the .75 would a up rated or max rated motor.

 

[mguzzy]

....
Just trying to be frugal (cheap!), as I see used motors on Letgo and other marketplaces and wonder if they would fit. Would a Pentair work on a Hayward Super II Pump?

I hear ya Bro! I needed to put a new pump on my waterfall. I read and read and read about the hydraulics of waterfalls and flow rates and pumps and WHAT THE HECK! I figure I'm not trying to run my SWG on it, not trying to maintain high flow for the spa jets, not try to keep the right pressure for the filer.. I just what to move water. So, I bought an old used PowerFlowLX (pump and motor) for 50 Bux from my neighbor down the street, cause he retired is above ground pool... it pushes water is all I care. If it blows up I'll find another 50 buk special on Craigslist.