Submersible motor burning often

All,

Our submersible motor is burning often. The technicians there say it is because of low voltage, voltage fluctuation and also the fact that we use condensers to convert 2 phase to 3 phase. We have to depend on two phase since we get 3 phase power only for 5 to 6 hours in a day in Karnataka and that too in two splits. Typically we get 2 phase power from 10 PM to 6 AM and we have no choice but to use. The voltage is sometimes as low as 180V and of course it keeps fluctuating. Does anyone know solution for it? Things like voltage stabilizer etc.

I can be reached on my cell 09742201385 or email narasv@yahoo.com

Hi,

What make of the pump you are using ? I am told the standard ones like Texmo, CG etc have this problem. But the local ones from Coimbatore survives this ! I am not sure how !!

Also running motor on 2 phase for long also puts strain and that may be the reason.

Its not 2 phase power, its single phase or 3 phase what you get in karnataka. You make 2 phase out of this single phase, by using condensers. The controller does this for you.

Low voltage is due to TC getting over loaded with many IP connections, much beyond the capacity.

Regards

Murali

Hi Murali,

Thanks for your mail. No, there are just two motors on a separate transformer of 25Kv. I think it is because of voltage fluctuation - may be it is just me thinking. I would like to discuss more. Can I have your cell number?

Regards,
Siddramesh Nara

The three phase motors are designed to run with three phase supply only. Using condesers / controllers to use just two phases of power line to run a three phase motor often results in overheating of the motor and results in coil burning. This is because the controller is not of a pucca design but rather crude one. Better use a couple of single phase motors . The recent Texmo single phase motor of 2 HP capacity can irrigate fields up to 1.5 acres. You can use this to irrigate your fields alternatively.

Are there some voltage stabilizers or something that can be used? Any other alternative?

Siddramesh Nara
09742201385

YES.
In Bangalore.

Can you please send me the details and contact numbers if possible?

To my knowledge NO !
And one more caution : It is illegal to run a three phase motor with condenser booster to run on just two phase supply and you may be fined by the power board authorities .

Hi,

Have been reading about alternate option for submersible.  You may want to check out sugunapumps.com/borewell.html .
Not suitable if you are using the pump to irrigate using sprinkler or drip directly.

regards,
gg

This compressor motors are suitable for low yielding bore wells. In Chennai normally they are used where the bore well yield becomes low due to non recharging of underground water. Theses pumps don’t give continuous water supply but kinda “spits” . i.e. water is discharged in bits / pulses along with air. Air is compressed through a half an inch pipe into the bore well and at the bottom this half an inch pipe is joined with a bigger one inch pipe. The compressed air pushes out water through the one inch pipe .

I don’t think this will be useful for agricultural purposes .

KPTCL employee himself provided on my request to me along with their advise. It may be off the record, but with affection on the basis of we having good terms with him.

Better get help from the professional to purchase them and avoid cheating by the sellers. Product from MEECO from Bangalore is the best. In addition to this if you go ahead as per your regular electrician who take care of bore well electrical activities, than it is just and proper for surety.

Farmers use a capacitor bank (100mfd/100V-4 numbers) to induce the non available third phase line voltage. This is done by removing the fuse (related 3rd phase line), connect the second phase line to one end of the capacitor bank and the other end to the load line (in the 3rd fuse carriage). This contact shall be made for a few seconds and parallelly you have to switch on the motor starter. Then you have to remove the contact. Now the third phase has been established. One has to ensure that the contact to be removed, otherwise it damages the motor. this is my experience.

Dear Vasu,

Thanks for the info. Can I have your contact number as I want to discuss a little bit more on this? You can mail me at narasv@yahoo.com

Siddramesh Nara

Submersible motors are designed to cool in water when it start running.
Non availability of sufficient water while it is started also leads to burn the motors.

Hi Vasudevan,

Not its not the farmers, its the engineers who have come out with this solution. Well a 3 phase motor works like this. The coil will have this 3 phase, ie 3 rotating field are induced , The rotor which is magnetised tries to catch up with this rotating field thus, we get rotary motion.

Due to load and other factors, the power companies, will remove the other 2 phases and  supply only one phase. Coz they think all the house hold eqpts run on only one phase, where as all industrial and agricultural IP pumps need 3 phase.

Now comes the capacitor banks, when this is connected to the second line, we have 2 phases, one from the pole, another created by this capacitor, (90 Dec out of phase), So with this 2 phases we still have a rotating field in the coil, and the rotor tries to catch with this. But in this situation, there will be load on the motor as for doing the same job, instead of 3 phases, only two are being used. That much more current will be drawn, there by reducing the voltage. This is a cumulative process and finally the coil burns down. Now automatic starters do this job, both in manual or auto mode.

Regards

Murali

It is a common problem. Here are few suggestions based on my own experience of running motor on 2-phase with capacitors for more than a decade.

  1. Avoid using capacitors for submersible motor, if water table isn’t too low (beyond 60 ft). Taking out submersible motor every-time is a big hassle.

  2. Main problem is transformers…if multiple people are using capacitors to run their motors in 2-phase electricity supply on same transformer, there is higher risk of burning motors. Keep bugging the electricity board to change your transformer/increase the capacity, keep them complaining about low voltage and frequent motor burn. I know they don’t care…

  3. Motors more than 5 HP, never worked well for me with capacitors.

Govt supplies 24 hours uninterpreted electricity to industries by hook or crook, but grumble of shortage of electricity when it comes to supplying to farmers…more or less situation is same in every state

Thanks Murali, Vasu and Kisaan for your suggestions.

  1. Not running motors on capacitors is not a option as we get 3 phase power only for 6 hours max, that too in two splits in different shifts every week. If it is given in one stretch, it will be more useful as again the land will be dry and it takes water and time to become wet. Since the water requirement is high, we have to use capacitors.

  2. Yeah, I am sure everyone will be doing this.

  3. Any reason why you say that?

What other options do we have folks?

Siddramesh Nara - 09742201385

Hi Siddaramesh,

The technical reason is that the TC is for some rated power in 3 phase. Say it can support 100 HP in 3 phase. If three phases are not available and if every one uses the single phase with capacitors, the TC will get overloaded. Now only one phase of the TC is working in overload mode.

Now you have the problem, More load, the voltage comes down. lower the voltage means more current your pump draws, more current in your pumps coil, more it gets heated, more it gets heated and beyond a limit, it burns.  :astonished:

The problem will be worse if you are in the last leg of the TC line. Now you see why the bulbs in villages all glow like zero watt ?? The largest consumption of electronic chokes for tube light is from rural sector. This is the reason. Low voltage. That is the reason now KPTCL is coming out with separate 3 phase lines for IP sets. But it will be no longer free.  ;D

Best way is, if you can afford, go for a 10kVA genset 3 phase. cost 60 to 70k, runs on diesel, but consumes 100 Rs per hour. So for 10hrs / day, running cost is 30K per month  :astonished:  :astonished:

Regards

Murali

Better to use a high voltage Stabilizers which can be found here. at moglix. and use Automatic Motor Starters.

These two will solve your problem and help to prevent to burn your Submersible motor, as the light fluctuation will not affect your Submersible motor.
I was had the same situation, but in my case the power comes only 10PM to 5AM, so it was difficult to manage it, but my technician implemented these 2 and everything is smooth now.