Study of water pumping system and Effect of Poor Quality Voltage on Motors

TDSL Project

By

Suneet Sawant – 12D070019

Himanshu Yadav-10D110054

Lalith Kishore A K -11D170029

Pratik Rao -RIT, Sangli

Guide: Prof. Priyadarshini Jadhav

Centre for Technology Alternatives for Rural Areas (CTARA)

Indian Institute of Technology, Bombay

Summer 2013-14

Introduction:

Background of the project:

Mr. Gahane (Junior Engineer, Water Supply Department, Shahpur, Dist: Thane) reported

various problems for the water pumping scheme in the following regions of Shahpur district.

1. Kothare-Jalkewadi (voltage fluctuation issue)

2. Ranvihir (motor winding issue)

3. Sakarli-Bandhanpada (voltage fluctuation issue)

4. Sakarli -Sawarpada (voltage fluctuation issue)

5. Tembhurli (voltage fluctuation issue)

6. Kambe (transformer capacity issue)

After talking to the concerned persons of the following villages we got to know that the issues

of Sakarli-Bandhanpada, Sakarli -Sawarpada, Tembhurli has been resolved by some

modifications. Kambe does not have a working water pumping scheme in existence yet. So the

main concentration is to study the problems reported by the “Ranvihir” water pumping scheme.

Ranvihir had reported repeated motor winding burnout issues. Ranvihir. Ranvihir and

Dolkhamb pump houses are close to each other. We have a remote monitoring device installed

in Dolkhamb.

Goals:

1. To study and understand the current drinking water pumping scheme in Ranvihir village

located in Shahapur taluka of Thane district.

2. To check the reasons for problems mentioned above (i.e) motor burnout issue.

3. To check the precautionary steps being taken and suggest more.

4. To study the efficiency of the pumping scheme installed in Ranvihir.

5. To analyze the data of Dolkhamb. Similar issues were observed in dolkhamb so we

needed to draw some parallels between the two cases.

Work plan:

1) Get the related documents about the design and cost estimation of the Ranvihir Water

Pumping scheme from Water Supply department of Shahapur Panchayat Samiti.

2) Install our Power Analyzer and get the data of the voltages and currents for a week.

3) To get the data and analyze it for voltage fluctuations.

4) To measure the flow rate and the head of the pump consequently finding the output

power.

EQUIPMENTS USED

Power analyzers

The Power Analyzer device monitors a wide range of parameters such as Voltage, Current,

Harmonics, Frequency, Power Factor, Real Power, Reactive Power, Total Power, etc.

Figure 1 power analyzer

The Data logger

This device logs the required voltage current and power data in its internal memory when the

aforementioned Power analyzer is interfaced with it. It requires a 24V DC supply. For this

purpose we bought a DC adapter.

Figure 2 Schneider Data logger (EGX 300)

Split core current transformer (current ratio 100/5)A

A current transformer (CT) is used for measurement of alternating electric currents.

Figure 3 Split core current transformer

Note: All the devices are owned by the CTARA.

The major problems that were reported

1) Voltage Fluctuation: Burns Stator Windings

2) Single phasing: Puts excess load on 3 phase motors causing stator burnout

3) Power Shedding: Irregular power shedding causes load on heavy motors. It causes

sudden surges in motor current resulting in burn out

FIELD VISIT

Ranvihir Pumping Scheme (design)

(From the documents obtained from Mr. Gahane (JE)–water dept. Shahpur)

Village RANVIHIR is situated in Taluka Shahapur of Thane District.It is at a distance of

23 kilometer from Shahpur.Village is situated interior to Nashik road.

Ranvihir water supply scheme is designed with a 3 phase 25 Hp submersible pump to

run 8 hours a day to fill a tank of 90 cubic mt. to serve a population of 1833 as per 2007.

Production well details:

The Ground Level is 100mts, Local Sea Level is at 99.5 mts and the bottom of the well is at

87.5 mts.

Reservoir tank details:

It is located at a Ground Level of 236 mts, Container Bottom at 235 mts and Water is being

pumped into the reservoir at 238 mts.

Total head= 150.5 mts.

The Electricity meter got burnt out two months before our visit.

Motor winding got burnt out twice in last year.

We installed the data logger to observe the readings for period of two weeks.

Equipment seen in the pump house:

Fuse: To limit the current drawn from supply to a certain value. Fuse capacity is 200A, 415V

Capacitor bank:

It protects the motor from sudden voltage changes, reduces harmonics, also supplies

reactive power and helps in maintaining the power factor. The capacitor bank, although is

not connected/not in use.

Switch changer:

It allows switching between the two motors, a Standby equipment. We can run either motor 1 or

motor 2 but not both at the same time. But the connections are not made for that.Right now to

switch to the standby motor the person in-charge must manually change connections at the

motor, in the well.

Star-Delta starter:

This is a starting method that reduces the starting current and starting torque. Star delta starter

design normally consists of three contactors, an overload relay and a timer for setting the time

in the star-position

Figure 4 control panel of pumping system

Figure 5 inside of panel

Figure 6 main switch

Figure 7 burnt meter

Figure 8 CT connections

VISIT SUMMARY

Place: RANVIHIR Pump House

Situated off-roads, a 45 minute hike from Ranvihir. Or a half hour hike from dolkhamb.

Contact: Ghorpade (8806838001)

Motor details:

3-phase motors, there are two motors of 15HP and 10HP according to Mr. Gahane (10

Hp pump not in use)

How many hours do the motor run a day:

3 hour per day mostly during morning according to Ghorpade (pump operator)

Is there any safety circuitry:

Has fuses. Rating 200A, 415V and 63A, 415V.

There is no OCB installed.

Single phase detector is not installed.

Is capacitor bank installed:

No the capacitor bank is not installed.

What are the general problems you get:

Load shedding: from 12:00 to 3:00pm and 6:00pm to 8:00pm according to Gram

Sevak, Ranvihir.

We made three visits and we did not have any power during the first two visits

Availability of water: the houses get the water in the tap for about one hour according

to the villagers.

Apart from Ranvihir scheme we also analyzed data from the Dolkhamb pump house which had

remote logging power analyser.

As the Dolkhamb pump house is situated close to Ranvihir pump house, analysis of the voltage

data may help us understand the voltage quality in these areas.

Voltage analysis for the Data of Ranvihir

The plot of the voltage over a period of about 2 hours is shown below

As per IS 325 and IS 12615

The permissible voltage range is 415± 10% (line vtg)(obtained from Kirloskar’s website)

Figure 9 Analysis of Ranvihir Data

From the above analysis the voltage was in the range of 192V to 225V for about 80 to 85

minutes in every phase, i.e the voltage was beyond the permissible voltage limit for more than

50% of the time. Hence we observe a poor voltage quality in Ranvihir. (Find the attachment of

spread sheet ”analysis of ranvihir data”)

Observations from Voltage analysis for the Data of Dolkhamb:

We analysed the data of Dolkhamb for over a period of 20 days.

We observed a wide range of voltage fluctuation.

There was single phasing for about 20 hours for the data of 20 days.

Figure 10 analysis of Dolkhamb data

We have grouped the available data from 10th feb to 28th feb and grouped it in to the ranges as

shown in the above figure.

We observe a wide range of voltage fluctuation over the period. We observe for a considerable

time the voltage goes below 140V, i.e there is low voltage problems and cases of phase

dropping.

Causes of motor winding burn outs

Eighty percent (80%) of motor electrical failures are a result of stator winding burnout.

Most winding failures occur due to primary or secondary single-phasing, extreme high or low

voltage, phase unbalance on three-phase motors, high voltage surges, or direct strikes of

lightning.

Effect of Single Phasing

The following are the effects of single phasing:

1) Due to single phasing the current in the remaining two phase increases and it is

approximately 2.4 times the normal current value.

2) Single Phasing reduces the speed of the motor.

3) The motor becomes noisy and starts vibrating due to uneven torque produced in the motor.

4) The windings will melt due to overheating and can give a fatal shock to the personnel.

5) It may cause overloading of the generator.

We can use single phase detectors to prevent loss due to single phasing.

Problems faced in Ranvihir while collecting the data.

We had installed the monitoring device, after a week when we went to collect the data we

found that the dc adapter that was supped to power the data logger was not working. Hence we

could not log the data. We collected the data for voltages in our last visit for about two hours

(3:00 to 5:00pm) with an interval of 5 minutes.

We also took the ultrasonic meter to measure the flow rate with a hope to make some

efficiency calculations, but the flow meter did not work.

CONTACTS:

Mr. Gahane (J.E. Water dept. Shahpur): 9403599975

Ghorpade (pump house operator, Ranvihir): 9209470286

Gram sevak (Ranvihir): 9209583282

REFERENCES:

Documents of the Ranvihir Water Pumping Scheme obtained from the water dept., Shahpur

Panchayat Samithi.