Variable Frequency Drive (VFD) for submersible motors

Have anybody tried using VFD for submersible motors? This device looks promising for achieving several things together :

  1. Converting 2 phase voltage to 3 phase voltage
  2. Varying frequency of the motor inputs to achieve different RPM for different load conditions
  3. Slow starting feature (without capacitors) to minimize motor damage due to starting current
  4. Increasing the power factor to save electricity and achieve higher energy efficiency
  5. And many more advantages like not requiring a separate control panel, PF capacitor etc

Wanted to know if anybody have experience in this front. Especially in the face of consistent failure of the 3 phase grid and increased motor failures, I am looking for alternatives.

More informations of VFD can be found here : … er_vfd.htm

I could find couple of Coimbatore based firms providing VFD solutions : … /ac-drives

Every farmer in my area are converting 2 phase to 3 by connecting a condensor. The phase gets shifted by 120 degrees(theoritically).

They do this but they are running at the cost of life of the motor. Because when phase is shifted the voltage is drastically reduced.

The point is not the money, the time for repair in case of frequent failures.

In Tamilnadu(around Coimbatore) few farmers started generating power with solar/wind power hybrid system.
They are planning to generate surplus electricity and the whole village will sell the power to TNEB.

In my opinion alternative or renewable energy is better solution.

Renewable energy should always follow energy conservation and energy efficiency whether that is agricultural pumping or any other application. Once you’re able to reduce demand – in this case through VFD drive or through other methods such as micro irrigation or mulching – you will require a smaller capacity renewable energy generation system thereby saving you a lot of money as such systems tend to be expensive.

Thumb rule is: reduce demand first then go for energy generation.

Solar pumps are long term solutions. In fact the solar pump controllers themselves use a variant of VFD technology to drive the motor…

And it is for the same reason as you mentioned (life of motor), VFD looks promising because the passive converters like capacitors do not do the conversion in a safe manner. Such crude methods results in poor efficiency and damage.

Good to see technical stuff being discussed here. Yes I agree solar is next solution for water pumping needs. Its not long before we run short of coal and water which contributes majority of power generation in India.

As far as the VFD’s are concerned, just the mere presence of VFD’s would not suit everyone requirement. Basically VFD’s output frequency which is motors input will vary depending on the power output from the solar panels. So the pump runs at slower RPM when power across the panels is less and runs at full RPM when power across panels is strong.

We have now started offering pump controllers which have VFD along with MPPT + grid sharing + dryrun protection.Now this tracks the max power available at any given time and runs the pump accordingly. Also, when sharing mode is switched on the defecit power if required is shared with mains.

Contact me if you need more info or interested in our solution.


Saravana Kumar
Greencurrent Solar Energy Systems

It is not advisable and it will lessen the Life of the Motor and Frequent Breakdowns will occur.It  will also put Load on the Transformer and have the Chance of Burning Transformer.It is not authorised by the Department.If they notice thy will file a Criminal Case.Hence don’t go for tht device.

for Vasudha Green Farms,

Hello Mr.Manne,

Technically talking VFD reduces the stress on the motor there by improving the motor’s life. You will agree if you know technical aspects of VFD. Also, please be informed a or any transformer will burn when 1)Voltage across the core is more than rated voltage, 2)Current drawn by the pump is more than rated current and most importantly in case if there is a short-circuit and all this has got nothing to do with VFD.

I have never come across any GO prohibiting use of VFD’s. Kindly do share any specific information you may have. It will be very useful to we members here.

Also, please note that the solar pump converters used in solar water pumping make use of VFD and MNRE has not objected to it in any of its policies as far as my knowledge goes.

Please share your facts.


Saravana Kumar

Hi every one,
As you have mentioned about the VFD and MPPT this system if failure as VFD is not ment for water pumping its used in industrial motors .
There are specialized designed inverters which give sure sinewave 3 phase output required by the pump motor and these inverters are to smart to take maximum out put from tje SPV.
This inverter have power sharning featuer which can share power fromvyour grid too or the opptinal battery bank.
This solar water pump inverter can be intalled with or with out battery bank.any further detail mail to

Hi Rakesh,

Merely stating VFD model solar pumping is a failure does not make any sense to me. I have personally seen cases where VFD are a big hit and the inverter’s a failure.

My views on this;

A)VFD is a proven technology and hence recommended by MNRE as well
B)There are VFD’s available for non-industrial applications, which are specifically used in water pumping application
C)Most of the inverters you talk about are imported, I would appreciate if you can point me a supplier from India manufacturing such inverter @ a competitive pricing
D)I agree that inverter’s give us a option of connecting and sharing grid , but why would anyone having a grid opt for solar?
E)I also agree you can have battery back up, but the cost?
F)Of all the success stories published in virtual and print media, I have rarely come across a story that deals with inverter model pumping, probably you could share some success stories here

Last but not the least;

You can pitch in your products, create a healthy competition, you have all rights as we share a public platform, but getting your facts right is a absolute must

There are members who have posted similar tag topics, when confronted they seem to disappear.

Hope to see your reply soon.


Saravana Kumar
Greencurrent Solar Energy Systems