Slowing a Capacitor-Start pump motor

[nooboo]

I bet someone here knows how to do this:

Picture a water transfer pump, a Tsurumi LB480, submersible, 2/3hp, 230v, 1ph, 60 hz, capcitor-start...I want to slow the GPM it delivers and I am thinking that slowing the frequency will slow the motor and slow the GPM flow rate.

I have checked around with my friend Google, but after writing the manufacturer reps, I am told they don't have a device. I asked at Davis for AC Drive / Frequency Inverter, 200-240 VAC single or three phase input with 3 phase output, 2.4 max. ; not suitable, 3 ph out..

Well, I do agree that slowing down the frequency of the power will slow down the pump. I know that can be a problem when running 60hz equipment (like fans) internationally because they often only have 50Hz. But I don't have the right equipment to offer to do that with the pump you have

Tsurumi says it is possible and OK to use a VFD on the pump, just not above 60hz. The VFD's I reviewed are not suitable for the capacitor-start.

The motor has blk, wht, green wires, to be used in the US, 110/220/1ph,60hz.

b

[hj]

Install a valve on the DISCHARGE pipe from the pump and you can throttle it to any GPM you want. It would not work on the inlet to a pump, even if there were a way to do it.

[ActionDave]

It would need to be a permanent,split, capacitor motor to be slowed down. Cap start and other single phase motors need to reach full speed quite soon or the starting winding will fail.

Hj has a good idea. An added benefit of clamping down on the water is the extra back pressure will be easier on the motor.

[LLigetfa]

Install a valve on the DISCHARGE pipe...

+1
A dole valve is a common and acceptable way to reduce the GPM output. Did you want to reduce the GPM or vary the GPM and why?

[BobL43]

Install a valve on the DISCHARGE pipe from the pump and you can throttle it to any GPM you want. It would not work on the inlet to a pump, even if there were a way to do it.

As long as it is a centrifugal pump, that would be fine. That could even reduce the current the motor will draw; less GPM transferred means more water just spiining around inside the pump body, using less work to get stationary water in motion.

[hj]

As long as there is some flow. Completely stopping the flow would cause the water to heat up and turn to steam, then cavitation would damage the impellers.

[ActionDave]

As long as there is some flow. Completely stopping the flow would cause the water to heat up and turn to steam, then cavitation would damage the impellers.

That makes for a really bad day.