Inverters

Then you must not have looked here: http://www.google.com/#sclient=psy&hl=en&q=single+phase+vfd&aq=f&aqi=g4g-o1&aql=&oq=&gs_rfai=&pbx=1&fp=6248f386b3c06fd8

Yes, they are made.

That is not the right way to answer a question, if u don't the answer let others to answer but don't direct the person to a deep sea water.

Did you look at any of the links provided by Tornado? Several of them were direct answers to the OP's question!

Most single phase motors however are Capacitor Start or Split Phase, neither of which can be controlled with inverters without damaging the motors, the inverters or both

Well, i am not controlling , i just feed the motor with the AC supply (it is rated to) via the inverter.what is the problem with that ?

In that case, what would be reason for using an inverter? You wouldn't perchance be trying to build some sort of perpetual motion machine?

I mean to run the motor via inverter in case power fail.

Ah, in that case why not just use a suitably sized UPS? These are available, of the shelf in virtually any output capacity and runtime that you could possibly need.

Excuse my slow understanding, what type of inverter you talking about , according to my poor knowledge i know that inverters are used to invert the DC to AC voltage.

An UPS goes AC→DC→storage battery→DC→AC.

They need power to run, so energy consumption will go up, not down. However, if the power fails, they will keep the load running for as long as the battery lasts.

They do contain inverters, though they are not intended to be used as energy saving devices. To save energy, look elsewhere.

Use a UPS then. But you may need to over size it to be capable of starting the motor. Look at the surge capacity of the UPS, and compare that to the Locked Rotor Current of the 1 phase motor.

Invertek's single phase inverters are what I was referring to above. They can ONLY be used on PSC and Shaded Pole motors.

Moot point though, the OP was not referring to speed control.

Yes, the link confirms suitability.

OP mentions energy saving and I stated speed control would be the obvious way to achieve this if application allows.

GA

I would add: remove the Capacitor that is in series with the 2nd winding and connect an equivalent resistance (1/cω ) with the adequate power dissipation.Connect the inverter 3 phases on L, N and the resistance end. Finally, parameter the drive to give the adequate voltage output maximum as Motor Nominal volt / √3

Do you think this is OK?

Excuse my slow understanding, what type of inverter you talking about , according to my poor knowledge i know that inverters are used to invert the DC to AC voltage.

OK! in different countries because of translation the same thing may be called different. I have meant the frequency converter, drive, inverter, German- Umrichter being the same kind of device.

Thanks, now i understand you mean VFD(Variable Frequency Driver), is that what you mean ?

<...trying to reduce the power consumption on pump motors...>

• Turn them off.
• Check that they are not over-rated for the hydraulic duty, and change the ones that are.
• Put them on time-switches or their electronic equivalent: the Building Management System.
• etc.