Hello I m trying to help farmers in our village whose motors are burnt with low voltage . Basically they have submersible.motors to pump water and the government is giving very less voltage either there are too many motor connections or too less voltage coming in from the power station it self. My question is can we build any circuit that would not start the motor if the voltage is less than 230 volts ac and if the voltages comes higher than 440 V AC. Please let me know how I can achieve this and save money for poor farmers who are wasting money on burnt motors. Thank you in advance.

 

Hello I m trying to help farmers in our village whose motors are burnt with low voltage . Basically they have submersible.motors to pump water and the government is giving very less voltage either there are too many motor connections or too less voltage coming in from the power station it self. My question is can we build any circuit that would not start the motor if the voltage is less than 230 volts ac and if the voltages comes higher than 440 V AC. Please let me know how I can achieve this and save money for poor farmers who are wasting money on burnt motors. Thank you in advance.

I cannot think of anything that would be remotely useful or minimally affordable for dealing with those power levels.
If there will NEVER be a solution to government provided electricity distribution, then the alternative is to develop local electrical service via some combination of solar, batteries and generators.
For example, if the government provided electricity is capable of charging batteries, then running the pumps from charge batteries would be both reliable and predictable.
I think the solution to your problems need to cover a wider range of solutions. I don't foresee a single solution and I don't see any easy fixes.
Maybe somebody smarter than me has an idea(s) that could help.

 

Thank you so much for your prompt reply. I did not know this was so complex I do like the idea of using batteries and that's how we do in our data center use series of batteries and have our servers powered on even in a disaster. I really wished the companies that make motors with stand high/low voltage so that poor farmers don't have to go through this. Please let me know if you come across anything related to this.

 

Thank you so much for your prompt reply. I did not know this was so complex I do like the idea of using batteries and that's how we do in our data center use series of batteries and have our servers powered on even in a disaster. I really wished the companies that make motors with stand high/low voltage so that poor farmers don't have to go through this. Please let me know if you come across anything related to this.

In the early days of electrification in the United States there was a battle between Edison and Westinghouse over the use of DC versus AC. Ultimately AC became the prevailing method of power distribution in the United States and subsequently the rest of the world. One other legacy was that many building operators installed elevators that utilized DC electric motors. The elevators and their motors remained in service for over a century. Con Edison, the power company for New York City, was REQUIRED to provide DC electric power well into the 21st century. If there were pumps that ran on DC power that could provide a beneficial alternative.

https://www.trainorders.com/discussion/read.php?11,1541316
https://cityroom.blogs.nytimes.com/2007/11/14/off-goes-the-power-current-started-by-thomas-edison/

Since you are associated with a data center, I'm going to guess that you know something about inverters. These are devices that use a battery to generate an AC output. the problem is that finding one to generate the power required by a pump might be a challenge. It is also possible to have a gasoline powered generator produce an AC output. I think the cost of gasoline in non-OPEC member states would pose a severe problem for the farmers. To say nothing of the contributions to pollution and global warming. I really have very little clue about things that will and won't work for you and them, so don't draw any conclusions about what I am proposing, except that I am trying to help.

You mention having motors withstanding a low voltage condition. If you could detect that the motor had stalled and shut off the current it might prevent the damage. In the case where the shutoff is activated you don't want to allow the motor to be turned on again if the voltage is just going to immediately collapse. Maybe there is a set of conditions that would trigger a shutoff, but require some period of normal power levels before turning back on again. I can think of complicated ways to do it, but not too many simple ones come to mind. The PLC (Programmable Logic Controller) is an expensive piece of equipment that might be used in a factory to do the function you describe. If you can do it with a PLC, there might be a way to mimic just that function by a cheaper method.

 

You could perhaps use a circuit like this to control a solid-state relay or contactor to the pump motor.
The circuit may need some added hysteresis so the motor doesn't turn back on for the small rise in line voltage that can occur when the motor load is removed for a low voltage.

 

Just add one more somewhat similar circuit to keep the power off when the voltage is too high and you're done (except for the testing and revisions).

 

Just add one more somewhat similar circuit to keep the power off when the voltage is too high

The circuit reference I posted shuts off for both low and high voltages.

 

You could perhaps use a circuit like this to control a solid-state relay or contactor to the pump motor.
The circuit may need some added hysteresis so the motor doesn't turn back on for the small rise in line voltage that can occur when the motor load is removed for a low voltage.

Is there anything the 555 can't do? Awesome circuit find!

 

The work-around would be batteries, a wide-input-range battery charger, and then an inverter to power the motors. The big barriers are the cost and reduced efficiency.
A more reasonable scheme will be a tap-changing system to adjust the voltage out to the required voltage as the input voltage varies.
Tap changing is a mature technology used by many utilities and it works very well. Unfortunately I am not experienced in the best ways to make it work, perhaps there is an expert who can provide more detailed comments.
Even there, a large problem is that power out can never exceed power in, and the low voltage is probably due to low power, and that is beyond your control.

 

Guys, as this thread is nearly 3 years old I hope the OP has found a solution by now.

 

Guys, as this thread is nearly 3 years old I hope the OP has found a solution by now.

I also hope so, BUT given the reputation of some government organizations, I would not want to wager that the problem is solved, or even addressed adequately.

 

I have 2 other possible hacks that may be of some use .........

1) Put a Valve on the Pump-Outlet that significantly reduces the Volume of Water being pumped,
this will substantially reduce the Load on the Pump-Motors,
allowing them to run at much lower Current,
thus reducing Heat generation during low-Voltage events.

2) When a Motor burns-up,
replace it with a Motor that has around a ~50% higher Horsepower rating than the original Motor.
( this is while retaining the smaller Pump-Head )
or,
a smaller Pump-Head could be installed on an already existing good Motor.

In any case,
if the actual Electrical-Power being delivered to the Pumps can not be adequately regulated,
then the amount of Water being moved from point-A to point-B,
must be reduced when the Voltage drops more than around ~10%.

3 Other thoughts ...........
The Voltage-Drops being experienced could be aggravated by
the extremely long runs of Wire being used to get to where the Pump is located.
Buck-Boost-Transformers could be employed to overcome some, or all, of this Voltage-Drop.
They're expensive, but cheaper than a new-Pump-Motor,
and cheaper than heavier-Gauge-Wire-Runs to the Pump(s).
Too-High of a Supply-Voltage is usually "better tolerated" than a Supply-Voltage that is too-Low.

When replacing a Motor, or replacing an entire Pump/Motor-Package,
specify a Motor with a 1.50, or even a 1.75, "Service-Factor" rating. ( 1.XX-SF)
These Motors can withstand far more abuse than the
usual standard 1.00-Service-Factor-rated-Motors that are normally supplied with most Pumps.
Call several Pump-Manufacturers and talk to them,
and reference the ideas in this Thread,
and then go with what they recommend.
You may get "blown-off" by some Motor/Pump-manufactures, and threatened with "no-warranties",
but some of them will be very helpful and accommodating to your situation.

Shield the Pumps from the direct-Sunlight, using anything available.
Provide good Air-Flow around the Motor.
.
.
.

 

I have 2 other possible hacks that may be of some use .........

1) Put a Valve on the Pump-Outlet that significantly reduces the Volume of Water being pumped,
this will substantially reduce the Load on the Pump-Motors,
allowing them to run at much lower Current,
thus reducing Heat generation during low-Voltage events.

2) When a Motor burns-up,
replace it with a Motor that has around a ~50% higher Horsepower rating than the original Motor.
( this is while retaining the smaller Pump-Head )
or,
a smaller Pump-Head could be installed on an already existing good Motor.

In any case,
if the actual Electrical-Power being delivered to the Pumps can not be adequately regulated,
then the amount of Water being moved from point-A to point-B,
must be reduced when the Voltage drops more than around ~10%.

3 Other thoughts ...........
The Voltage-Drops being experienced could be aggravated by
the extremely long runs of Wire being used to get to where the Pump is located.
Buck-Boost-Transformers could be employed to overcome some, or all, of this Voltage-Drop.
They're expensive, but cheaper than a new-Pump-Motor,
and cheaper than heavier-Gauge-Wire-Runs to the Pump(s).
Too-High of a Supply-Voltage is usually "better tolerated" than a Supply-Voltage that is too-Low.

When replacing a Motor, or replacing an entire Pump/Motor-Package,
specify a Motor with a 1.50, or even a 1.75, "Service-Factor" rating. ( 1.XX-SF)
These Motors can withstand far more abuse than the
usual standard 1.00-Service-Factor-rated-Motors that are normally supplied with most Pumps.
Call several Pump-Manufacturers and talk to them,
and reference the ideas in this Thread,
and then go with what they recommend.
You may get "blown-off" by some Motor/Pump-manufactures, and threatened with "no-warranties",
but some of them will be very helpful and accommodating to your situation.

Shield the Pumps from the direct-Sunlight, using anything available.
Provide good Air-Flow around the Motor.
.
.
.

CAUTION!!!! Putting a restriction on the pump discharge flow will only work for some types of pumps. For some other types the motor current increases as the delivery pressure increases. And as for motor changes, probably not possible because the pump/motor is all one assembly: " Basically they have submersible.motors to pump water " is from post #1. Submersibles are seldom able to be altered very much.
Certainly assuring that the voltage drop in supply wires is not the problem is vital, but that does not seem to be the main problem. The installations do not seem to be here in the USA, where we mostly have quite stable electrical power.
Second quote from post #1: " and the government is giving very less voltage either there are too many motor connections or too less voltage coming in from the power station it self." So the TS does have a problem and it is not like some utility is available or even willing to help.
The fact is that we have it good, here in the USA. Elsewhere things may be different.