Low Suction Problems

[leezer99]

Just put a new motor on my pump and the suction is very low. Went from a .75 HP motor to 1 HP motor. Pump is a RS750CA.

1) 16,000 gallons
2) DE Filter
3) In Ground
4) Vinyl painted plaster
5) Hayward RS750CA with a new 1 HP Motor

 

[duraleigh]

Welcome to the forum.

Need more information.

Is the flow into the pool low? What is the psi on the gauge? Is their air in the pump strainer basket?

 

[leezer99]

Flow into the pump is low and not filling the basket area of the pump. PSI on the canister is 0. Yes, air in the pump strainer basket. Tried to prime it by dumping a bucket of water in when I started it up but didn't pull it down like it used to.

 

[duraleigh]

Yeah, You have a suction side air leak. Somewhere between the pump and the skimmer(s), air is being sucked into the system. Find that leak and your issues will be solved.

 

[leezer99]

Could it be that I put a 1 HP motor on a pump that says .75 HP / 1.32 SF / .99 THP on it without changing the impeller?

 

[duraleigh]

Yeah, that seems logical to me. The bigger pump will "pull" harder making the suction side more susceptible to air leaks.

 

[Bama Rambler]

As long as the motor sfhp is equal to or greater than the current sfhp (. 99) then it will be fine. The impeller is what regulates the dynamic of the pump so changing the motor doesn't really change anything as long as the speed matches.