to many rpms ?????

[whitetail farms]

I have limited my vacuum troubles down to the motor im running a 3 horse with 1750 rpm witch is what the pump calls for but the motor bogs down under load so what would happen if I put a 3hp motor with 3450 rpm on a sihi pump?

Thanks for your help nick

[mellondome]

You would be better served with a bigger motor. 3hp is still 3hp even if it is trying to turn faster.

[madmapler]

I remember a while back you were trying to find a model# on that pump. Did you ever find it? My 3 hp. 2 stage is a 3450 rpm. I know yours is a single stage. I guess if you are sure its 1750 then it does'nt really matter. Is it connected with a coupler or pulleys?

[whitetail farms]

its a sihi single stage 3404,the motor surges and doesn't run consistently when its hooked to the releaser but when its un hooked it run fine if you dead head it the motor dies right down after a little bit

[bees1st]

what kind of motor is it ? Is it a capacitor start ? Just because it's 3 hp doesn't mean it suited for the job .

[whitetail farms]

and I used a love joy coupler to connect the pump and motor.

[500592]

Have you tried adjusting the cooling water with it hooked up maybe that could be your issue.

[madmapler]

I just read a chart that said the coolant should be about 3 gpm. It sounds as though the motor is not enough but according to the specs you're right on. Is the motor new? Maybe its defective.The other thing I was thinking is perhaps the bearings on the pump are going. I hope I dont have this much trouble with my pumps. I'll be setting up 2 of them for the first time this year.

[BreezyHill]

the motor surging like that is often a spent motor. if it gets up to speed on capacitor start the caps are fine. 3450 on a 1745 will either not get up to speed or it will over heat as there will not be enough hp to maintain the speed,

this is all provided that you are running a 240 motor on 240...240 on 120 will do similar. if there is a burned out section it is just like running a 240 on 120. if a rodent chewed the wore and you are not getting connection the same issue occurs.

I would use a multimeter to check voltage at the motor connections...being carful not to short any leads and so see that you have proper voltage on L1 & L2.

If L1 to grd or L2 to ground is low you have your answer. if they are all good then the motor is likely scrap. Replace with what the manufacturer calls for. Many hours go into engineering motor sizes for applications.

[whitetail farms]

PROBLEM SOLVED!!!! I brought the motor back to the shop that wired the plug into it and they tested said it wasn't getting enough volts, found out the guy wired it wrong he fixed free of charge and now the pump is working good even when I dead head it,now hopefully I don't have any troubles with the releaser. thanks for all your help though guys