LABORATORY MODULES ELECTRICAL MEASUREMENT · Power in electrical engineering, is defined as the amount of electrical energy that is transferred in an electrical circuit in a time

2020

High Voltage and Electrical

Measurement Laboratory

Universitas Indonesia

LABORATORY MODULES

ELECTRICAL MEASUREMENT

High Voltage and Electrical Measurement Laboratory

Department of Electrical Engineering UI

ELECTRICAL MEASUREMENT LABORATORY MODULE 2020 2

Contents Module 1 Laboratory Briefing & Pre-Test .......................................................................................... 4

Module 2 Impedance Measurement ...................................................................................................... 5

I. Objective .................................................................................................................................... 5

II. Basic Theory .............................................................................................................................. 5

III. Experiment Equipment ............................................................................................................ 12

IV. Experiment Procedure.............................................................................................................. 12

Module 3 Single Phase Power Measurement ..................................................................................... 14

I. Objective .................................................................................................................................. 14

II. Basic Theory ............................................................................................................................ 14


IV. Experiment Circuitt.................................................................................................................. 21

V. Experiment Procedure .............................................................................................................. 21

Module 4 Power Quality and Three Phase Power Measurement .................................................... 23

I. Objective .................................................................................................................................. 23

II. Basic Theory............................................................................................................................. 23


IV. Experiment Circuit ................................................................................................................... 26


Module 5 Lighting Measurement ........................................................................................................ 29

I. Objective .................................................................................................................................. 29

II. Basic Theory............................................................................................................................. 29


IV. Experiment Procedure.............................................................................................................. 33

Module 6 Grounding Resistance Measurement ................................................................................. 35

I. Objective .................................................................................................................................. 35

II. Basic Theory ............................................................................................................................ 35







Module 7 Energy Consumption Measurement .................................................................................. 42

I. Objective .................................................................................................................................. 42

II. Basic Theory ............................................................................................................................ 42



Module 8 Post Test ................................................................................................................................ 46




MODULE 1

LABORATORY BRIEFING AND PRE-TEST

Laboratory Briefing is held on February 19, 2020 at 18.30 PM located at MRPQ Auditorium

Lv. 4. Attendance to briefing and pre-test is mandatory and will be included in the scoring system.




MODULE 2

IMPEDANCE MEASUREMENT

I. OBJECTIVE

1. To know LCR Meter and its function 2. To know the construction of LCR Meter and how LCR Meter works

II. BASIC THEORY

LCR meter is an electronic electrical measurement to measure resistance, inductance

and capacitance value. The utilization is relatively easy since today, a digital LCR meter is

already in the market, and it makes the user easier to use it. Here is a brief explanation about

resistor, inductor and capacitor

Resistor is an electronic component that has the function to control and limit electricity.

It is also used to limit the amount of current flowing in a circuit. According to its name, resistor

is resistive and mostly is made from carbon. The unit of resistance is Ohm and symbolized by

omega. Type of resistors mostly has the shape of tube with two copper legs. There are colored

circles in the body to make the user know about the resistance without measuring it using

measurement device. (example: ohm meter)

Figure 1. Resistors types




Inductor is symbolized by L. Usually in a form of coil, but sometimes has other forms

too. Inductor or coil is one of passive components that is made up by coils and usually save

up energy in form of magnetic field. The unit for inductance is called Henry (H=Henry, mH

= millihenry, etc). An inductor is called as ideal if it has inductance, but has no resistance or

capacitance and does not waste much energy.

Figure 2. Inductors Types

Capacitor is an electronic component that can store electric charge in a certain time. The

definition of capacitor is electronic component that save electrical current charge in electric

field until a certain time by collecting internal inequity from electric current charge. Capacitor

was invented by Michael Faraday (1791-1867). The unit of capacitance is Farad (F). One farad

is equal to 9×1011 cm2.

Figure 3. Capacitors Types

LCR Meter is a part of electronic measurement device to measure inductance (L),

capacitance (C) and resistance (R) in component. In the simpler form of this device, the real




value of these units is not measured; so that impedance will be measured internally and

converted to be shown to capacitance that match or inductance value. The reading will be

accurate if capacitor and inductor of device tested do not have impedance significant resistive

component.

The basic resistor measurement principle with LCR-740 is WHEATSTONE bridge.

Wheatstone bridge is an electrical circuit consisting of two parallel circuit branches connected

with the galvanometer with the aim to measure an unknown electrical load. Wheatstone bridge

has four resistance arms, a source and a detector, usually in the form of galvanometer.

Wheatstone bridge can be used to determine the unknown resistance value, for example (see

figure 4), suppose R4, we determine the value of the resistor until current through the

galvanometer indicates the value of zero. Wheatstone bridge is said to be in equilibrium if the

voltage delta in galvanometer is zero volt, in this case there is no current flowing through

galvanometer. At Figure 4, I of Wheatstone bridge will happen if voltage at C to A is equal to

voltage from D to A, or if voltage from C to B is equal to D to B. In this case:

Figure 4. Wheatstone bridge




If galvanometer shows zero, hence:

By substituting equation (1-1),(1-2) and (1-3), we have:

If I2 from equation (1-1) is inserted, we got:

Equation 1-4 is a form of Wheatstone bridge equality. If three of the resistances are known

and one of resistance is unknown, for example R3= Rx, hence:




Principally, alternating current bridge is used to measure unknown inductance by comparing

it with standard known inductor. Figure 5 describes inductance comparator bridge; R1 and R2

are the comparator, and the standard arm is LS in series with RS, whereas LS is high quality

inductor and RS is variable resistance. Lx is unknown inductance and Rx is the resistance.

Figure 5 Inductance Comparator Bridge

If the arm of the bridge is stated in complex form, therefore:

In equality:




Two complex numbers are the same, if its real and imaginary are the same. By equating real

part of equation (1-5), hence:

For the imaginary,

Principle that is used for capacitance measurement is Capacitance Comparator Bridge,

which is similar to Inductance Comparator Bridge. Figure 6 describes capacitance comparator

bridge. R1 and R2 as comparator arms, and the standard arm is Cs (high quality capacitor)

which is series with Rs (variable resistance). Cx is capacitance whose value is unknown, and

Rx is capacitor leaking resistance.

Figure 6. Capacitance Comparator Bridge.

If the arms of inductance comparator bridge are stated in complex form, therefore:




In equilibrium, hence:

The same with inductance comparator bridge, two complex number is the same if its real

and imaginary are the same. By equating the real part of above’s equation, we have:

Hence the imaginary is:

Equilibrium is obtained by controlling the value of variable load, and variation of load

R2 and R1 to obtain minimum current flow in the galvanometer. After that the current that

flows through Galvanometer is reduced by varying variable load Rs and keeping R2 and R4

constant. And then keep load Rs constant and change load R2 and R4, repeat the process above

until the bridge is in equilibrium. After reaching equilibrium, capacitance can be obtained from

the equation above.

If the bridge circuit is not in equilibrium, then the current that flows to the galvanometer

causes a deviation of the galvanometer needle. The magnitude of the deviation is a function of

the galvanometer’s sensitivity. Hence, the sensitivity is calculated as current per unit(ampere).




The galvanometer needle deviation can be expressed linearly or the angle per unit. The

sensitivity S can be stated as

Thus the total deviation D is :

D = 𝑆 × 𝐼

The thevenin theorem is regularly used to find the current value that flows in the

Galvanometer hence the following equation is obtained :

III. EXPERIMENT EQUIPMENT

1. LCR Meter 2. Variable Resistor 3. Variable Inductor 4. Variable Capacitor

IV. EXPERIMENT PROCEDURE

1. Prepare all the equipment that will be utilized.

2. Prepare the components that will be measured.

3. Count manually the value of the components.

4. Then measure the components using RLC Meter.

5. Note the result of measurement.

6. Count total impedance of each load.

7. Find the power factor value from load impedance that is measured on LCR Meter and

power factor of load impedance that is stated on the load variable.




8. Compare power factor value of load that is measured by LCR Meter and load that is

stated on the load variable.




MODULE 3

SINGLE PHASE POWER MEASUREMENT

I. OBJECTIVE

1. To know and understand the characteristic of power and power factor measurement on

alternating current circuit with different type of loads.

2. To know the working principle of single phase wattmeter, cos phi meter, amperemeter and

voltmeter.

3. To understand the variation of power type in alternating current system circuitry.

4. To know the usage of power of light bulb, and compare it with the value of power in its

packaging box.

II. BASIC THEORY

Power in electrical engineering, is defined as the amount of electrical energy that is

transferred in an electrical circuit in a time unit (energy per time). Different with direct current

direct current circuit, in alternating current circuit, there are 3 kinds of power; True Power,

Reactive Power and Apparent Power. The three has tight relation to one another and it is

represented by a triangle, and called as power triangle.

Figure 1. Power Triangle




The difference between these kinds of power in alternating current circuit is caused by the

characteristics of impedance inductive and capacitive component. In alternating current circuit,

inductive and capacitive component has a certain impedance value due to frequency. These

inductive and capacitive components create lagging and leading of current with respect to

voltage, which will affect the multiplication between voltage and current, and as a result, there

are three kinds of power in AC circuitry.

The shape of power triangle is determined by the type of loads in the circuit; whether it

is resistive, inductive, capacitive or combined. The resultant of these loads is called by

impedance, and impedance has the combined characteristics based on which components

composing it. The characteristic of load means the type of power that is absorbed, and the

leading or lagging of the current with respect to voltage. The usage of inductive /capacitive load

will affect the current position with respect to the voltage, which usually the difference is

symbolized by phi, and the amount of cos phi is called as power factor. Power factor is the ratio

between active power and apparent power.

Hence, considering the angle shifting between current and voltage, power can be stated

as S = V x I*= P + Jq With: S → in Volt-Ampere, apparent power

P → in Watt, active power

Q → in VAR, reactive power

V → in Volt, voltage

I* → in Ampere, current

Notice in I, there is a star symbol (*). This symbol states that the value of current utilized

is conjugated mathematically. This equation also states that angle that is formed by voltage and

current is the subtraction between angle that is formed by voltage and angle that is formed by

current. Here is the illustration:




Figure 2. Relationship between voltage and current angles.

With : α=θ1–θ2 S = V x I* = V⦟ θ1 x I ⦟- θ2 S =V x I ⦟θ1 – θ2

In this experiment, analog measurement device will be utilized to measure current,

voltage, power and power factor. Analog measurement device mainly has similarities in having

firm and rotating coil that has been calibrated so the movement of its hand matches with the

amount that being read. There are some construction types of analog measurement device, for

example:

a. Moving Coil Type

How moving coil works is that it used 2 permanent magnets that will induct coil that

has current and connected with the hand of the measurement device. The bigger the

induction, the coil will rotate until the hand hits the damper. Moving Coil utilizes Lorentz

Force principle.

Figure 3. Moving Coil Construction




b. Moving Iron Type

It uses two soft steels; one is mounted in the coil and the other is connected to the hand of

the measurement device. When current flows to the coil, electromagnetic field will happen

and those two steels will have permanent field. • Attraction type: pair of steels will have different poles when facing one another.

• Repulsion type : pair of steels will have the same poles when facing one another. Figure 4. Repulsion type Figure 5. Attraction type

c. Electrodynamic type

How it works is almost the same as moving coil, but the permanent magnet in moving coil,

here is replaced by a coil that has current flowing through it.

Scale

Pointer

Movable

Coil

i2

Fixed Coil

Figure 6. Electrodynamic type construction




d. Induction Type

If inducting coil has current flowing through it, an alternating magnetic field will

happen. This magnetic field will create rotating current in the metal disk, and the current

will generate magnetic field too hence interaction with magnetic field from inducting coil

creates rotating force in metal disk.

Figure 7. Induction type construction

e. Electrostatic Type

There are two plates, both in half circle shape, that is set to be next to each other, but

one of them is not moving. These two plate is connected to an axis. The plate that can move

has a hand to show the measurement result. These two plate will have current flowing

through it and create electrostatic field that works based on coulomb law. The moving plate

will move due to the two force on the two plates that have different potential.

Figure 8. Electrostatic Type construction




f. Thermocouple Type

Two conductors that differs will be united in one end and separated in the other end.

The united end will convert heat energy that is received and will be flown to the other end. Due

to the different of conductor type, there is a potential different in the tip of the conductor.

Usually this type is combined with moving coil type by replacing its source from heat energy.

Figure 9. Thermocouple type construction

This is the measuring process by analog measurement device Figure 10. Measuring process by analog measurement device

Meanwhile for digital measurement device, it is divided into 2 categories:

a. Digital Readout Instrument.

Digital readout instrument is basically an analog device, where the

measurement process still uses analog circuit, but the reading of the measurement

is done digitally, like this:

Figure 11. Measurement process by digital readout instrument




b. Digital Instrument

This instrument fully uses ADC and microprocessor in data sampling

until the reading process of the measurement.

Figure 12. The measurement process of digital instrument


1. AC Amperemeter

2. AC Voltmeter

3. Single phase Wattmeter

4. Cos phi meter

5. Resistive load

6. Inductive load

7. Capacitive load

8. Light bulb

9. Fluorescent lamp

10. Cables




IV. EXPERIMENT CIRCUITT

Figure 13. The experiment circuit

*for wattmeter and cosphimeter wiring can be seen underneath the instrument itself.

V. EXPERIMENT PROCEDURE

A. Measuring power and power factor from different types of loads

1. Setting the experiment circuit as written in figure 13 2. Setting up the wattmeter and cos phi meter based on the guideline in the

instrument. 3. Setting up the load combinations 4. Turning on the source 5. Measuring and reading the measurement of voltmeter, amperemeter, cos phi

meter, and wattmeter 6. Repeating steps 3 to 6 with different types of loads.

B. Measuring power of light bulb and fluorescent lamp

1. Setting the experiment circuit as written in figure 13

2. Setting up the wattmeter and cos phi meter based on the guideline in the instrument.

3. Replacing the load by light bulb

4. Turning on the source

5. Measuring and reading the measurement of voltmeter, amperemeter, cos phi meter,

and wattmeter




6. Comparing the result with the power that is stated in the lamp’s packaging box.

7. Repeating steps 3 to 6 with fluorescent lamp.




MODULE 4

POWER QUALITY AND THREE PHASE POWER MEASUREMENT

I. OBJECTIVE

1. Understanding the definition of power quality 2. Understanding types of disturbance in power quality 3. Understanding the three phase power measurement using 1 three phases wattmeter and 2

single phase wattmeter. 4. Understanding the power factor measurement of RLC load of three phase circuit. 5. Understanding how wattmeter works.

II. BASIC THEORY

Power quality is a condition between electricity source and the supplied electrical

appliances. The power quality describes how good or bad the quality of electricity due to some

disturbances that may happen in electricity system.

Usually what are talked about in power quality is the disturbances that happen.

Generally, the quality of power has three important parameters, which is voltage, current and

frequency. Every deviation from voltage, current and frequency from its normal condition that

can make the quality of power delivered and system performance worse, and it could create

failure of system or the wrong electrical load operation from consumer side. Here are the problems of power quality: a) Voltage Drop, voltage that disspates due to impedance of the circuit

b) Transient, a phenomenon that involves variable change (voltage, current, etc) that occurs

during transition period from steady state to another state, transient is divided into : • Impulse transient : transient that only has one direction of polarity

• Oscillatory transient : transient that has two directions of polarity




b) Gejala Perubahan Tegangan Durasi Pendek (Short-Duration Variation) Short Duration

Variations is a voltage value changing phenomenon in short priod of time which is less

than a minute

Based on the duration of the incident, SDV consist of 3 types, which are : • Instantaneous : Voltage change occurs for 0.5 until 30 cycles • Momentary : Voltage change occurs for 30 cycles until 3 seconds • Temporary : Voltage change occurs for 3 seconds until 1 minute

Based on the voltage change value, SDV consist of 3 types, which are

• Interruption : reduction of voltage or electrical current until it is below 0.1 pu for a

period of time not exceeding 1 minute

• Sag : reduction of voltage or electrical current 0.1-0.9 pu in a period of 0.5 cycles - 1

minute

• Swell : increase of voltage or electrical current on 1.1-1.8 pu in 0.5 -1 minute

c) Long Duration variations is voltage changing phenomenon, in a long time period which

exceed 1 minute, it is divided into 3 types which are sustained interruption, undervoltages,

and overvoltages.

d) Voltage unbalance, a pehomenon where there is a voltage value difference in a three

phase system and also its phase angle

e) Wave distortion, for example is Harmonics which is a deviation phenomenon of a

wave (voltage and current) from its ideal form which is a sinusoidal wave.

f) Flicker : voltage variation caused by fast and continuous load change.

g) Frequency deviation, types : a. Frequency variation

b. Radio Frequency Interference : disturbance caused by electromagnetic induction from

an external source

c. EMF




The measurement of three phase power measurement use couple of methods: 1. Measurement using 1 three phase wattmeter (poly phase)

2. Measurement using 2 single phase wattmeter (single phase)

3. Measurement using 3 voltmeters and 3 amperemeters

4. Measurement using 3 single phase wattmeter (single phase)

5. Measurement using 3 V-A meter.

In this experiment, methods being used are 2 single phase wattmeters and 1 three phase

wattmeters. There are three construction types of wattmeter:

• Electrodynamic Type • Induction Type • Thermocouple Type

One of the most common AC wattmeters is electrodynamometer type wattmeter.

Figure 1. Electrodynamometer single phase wattmeter diagram.





1. 1 polyphase wattmeter 2. 2 single phase wattmeters 3. Cos phi meter 4. Resistive load 5. Inductive load 6. Capasitive load 7. Cables

IV. EXPERIMENT CIRCUIT

Here is the circuit of wattmeter installation in three phase circuit: a) Using 1 poly phase wattmeter.

Figure 2. Circuit of 1 polyphase wattmeter




b) Using 2 single-phase wattmeter

Figure 3. Circuit of 2 single phase wattmeters.


A. Power measurement with 1 poly phase wattmeter.

1. Setting up experiment with Z1 using resistive load, Z2 using inductive load, Z3 using

capacitive load, using wye or delta configuration of three phase load.

2. Connecting first probe to R phase and connecting output from probe which are P1 and

A1 to first load using three phase circuit.

3. Connecting P2 to S phase, and the second load that is not connected to first load.

4. Connecting T phase to second probe, then connecting the output of this probe which

are P3 and A2 to third load that is not connected to second load.

5. Connecting first probe to cos phi meter ke R phase, then connecting output from probe

P1 and A1 to first load in three phase circuit.

6. Connecting P2 to cos phi meter and S phase to the second load that is not connected

to first load.




7. Connecting T phase to P3 and third load to three phase circuit that is not

connected to second load. 8. Checking if cable connection installed properly and load had been switched on

before circuit is on. 9. After being turned on, observe and note the value that is read by two wattmeters and

cosphi meter.

B. Power measurement using 2 Single Phase Wattmeter.

1. Construct the circuit with Z1 as resistive load, Z2 as inductive load, and Z3 as

capacitive load, and create wye or delta configuration on three phase loads.

2. Connecting phase source R to the first single phase wattmeter, and from wattmeter

connect it to Z1 load of three phase load configuration.

3. Connecting phase source S directly to Z2 load of three phase load configuration.

4. Connecting phase source T to second single phase wattmeter, and from wattmeter

connects to cos phi meter. Then, connect Z3 load to three phase load.

5. Checking if cable has installed properly and load had been switched on before the

circuit is on.

6. After being turned on, observe and note the value on wattmeters and also cos phi

meter




MODULE 5

LIGHTING MEASUREMENT

I. OBJECTIVE

1. Understanding lighting concept 2. Understanding units in lighting measurement 3. Understanding lighting measurement device 4. Knowing application and usage of lighting measurement.

II. BASIC THEORY

Light is an electromagnetic radiation that can be caught by eyes and has wavelength from

0.4 x 10-4 -~ 0.75 x 10-4 cm. Light also can be defined as the amount of lighting on a working

plane that is needed to do activity effectively. Based on the sources, lighting is divided into 2

kinds : a. Natural lighting Natural lighting is lighting that is based on sun rays. b. Artificial lighting Artificial lighting is lighting that is based on any other sources, except sun rays.

Beside its source, a lighting system can be divided into 3 kinds, based on the distribution : a) Distributed lighting system

In this system, light illumination is spread evenly with the same strong light intensity

on the entire horizontal surface in the room. b) Localized lighting system

In this system, light is provided to provide highly selective illumination in a relatively

wide place or field. Usually installed with common lighting, where localized lighting is

used as lighting for work and distributed lighting is used as basic lighting.




c. Directed lighting system

In this system, light is concentrated from a particular direction to the work plane within

the space/limited area or directed to specific object such as painting.

One of the most common artificial lighting sources that utilized by human is lamp. Lamps

can be categorized into several types, according to the method that is used to emit light. These

lamps also has differences in shapes, power consumption, and also the heat/brightness. : a. Light Bulb

Light in light bulb is resulted from tungsten made-filament that shines due to heat. Only

8-10% of the energy is converted to light; the rest is converted to heat form. Halogen lamp is

included to this group.

Basically, filament in light bulb is a resistor. If an electrical current goes through it, the

filament turns extremely hot, and its temperature will be approximately 2800 K until 3700 K in

its peak. This causes the light color from light bulb is in yellow reddish. In that extremely high

temperature, filament will produce light in a visible wavelength.

b. Fluorescent lamp

The light in this lamp comes from phosphoric powder which covers the inner part of

lamp’s tube. The powder determines the color of the light produced. More than 25% of energy

consumed by this lamp is converted into light.

When a 220 volt of AC voltage is connected to one set of fluorescent lamp, the voltage

of the tip of starter is enough to cause neon gas in starter tube to be ionized and it will cause the

starter from normally open to closed, hence the neon gas inside will be deionized. In this closed

starter condition, a current will flow to heat filament of fluorescent lamp tube and the gas inside

the tube will be ionized. Once the neon gas in the starter tube is cooled enough, the bimetal in

starter tube will be opened again so the ballast will produce a high voltage spike and causes

electron jump from the two electrodes and shines the fluorescent layer on the lamp’s tube.

c. HID (High Intensity Discharge) lamp

The light in this lamp is caused by electrical prod using metal vapor. Mercury lamps and metal

halide lamps are some examples of HID lamp.




d. LED (Light-Emmiting Diode) lamp

This lamp is composed by a set of LED to emit light. The LED light will appear without

heating of the components. LED needs DC source to energize it with low voltages. Due to that

reason, a step down transformer circuit is also equipped to decrease source’s voltage that goes in

to the circuit.

In lighting measurement, some specific terms are used, for example:

a. Light intensity

It is the strength of light from a light source. The amount is measured in candela (cd) unit.

b. Lumen

Lumen (SI unit, symbolized by lm) is a unit for light flux that is emitted in a solid angle unit

by a source with light intensity of 1 candela. One lumen is equal to the amount of light

uniformly emitted of 1 candela in 1 steradian solid angle. It is written 1 lm= 1 cd sr.

c. Illumination

Illumination or lighting intensity is the amount of light exposing a surface. Illumination has

unit of footcandles (fc) or in lux form; 1 lux= 1 lumen /m2

a. Steradian

Steradian is a unit of space angle for a ball area in radius distance

Figure 1. Relationship of steradian, ball area, and radius distance.




Here is the conversion of units above:

From To With data Equation

Candela (Iv) Lumen (Φv) angle α Φv=2πIv (1−cosα2)

Lumen (Φv) Candela (Iv) angle α Iv=Φv2π (1−cos½α)

Lumen (Φv) Lux (Ev) Area A (m2) Ev=ΦvA

Lux (Ev) Lumen (Φv) Area A (m2) Φv=Ev⋅A

Candela (Iv) Lux (Ev) Measurement distance D (m)

Ev=IvD2

Lux (Ev) Candela (Iv) Measurement distance D (m)

Iv=Ev⋅D2

Measurement tool utilized is luxmeter. Luxmeter has lux unit, which is defined as a metric

unit of light on a surface. Luxmeter has light intensity range from 1 to 100,000 lux. Luxmeter is

constructed by three main components; case, LED and photodiode. The working principle of

luxmeter is to convert light energy to electrical current and it will be shown on LED screen.

Illumination measurement basically is a measurement that uses the approach of point source.

Illumination measurement is done in a dark place where there is no reflected light received by the

luxmeter sensor. There are three illumination measurements:

1. General measurement

It is a measurement that is done in one whole room. This measurement is done by dividing

the room into several measurement points with the same distance from one point to another.

2. Local measurement

It is done on a specific object. The object will be divided into several measurement points.

3. Reflectant measurement

It is a measurement of reflectant by doing twice of measurement. First measurement is to

measure lighting intensity on the surface by putting photo cell facing the light source. The second

measurement is by turning over the photocell facing the surface, and pulling photo cell until the

number on display shows highest number. The amount of reflectant is formulated here:

Reflectant= (Measurement 2/ Measurement 1) x 100%




Lumen measurement is important to save energy in lighting. The application of lumen

measurement can be utilized on these fields:

o Lighting level measurement on buildings

o Luminaire light intensity distribution measurement

o In videography, photography and architecture.


1. Luxmeter LX-1108 2. 1 Light bulb 3. 4 Fluorescent Lamp 4. 1 LED Lamp 5. AC Power Supply

IV. EXPERIMENT PROCEDURE

A. Voltage variation general measurement

1. Install the lamp in fitting in the middle of the room 2. Turn on the power supply 3. Adjust the power supply in the voltage that desired 4. Make sure the light in the room only comes from that source only. 5. Adjust the luxmeter position under the light with distance 1 meter above the floor. 6. Make sure the light that is caught by luxmeter sensor is not interfered by shadow.

7. Turn on the luxmeter, open the sensor cover, and note the value on the luxmeter. 8. Repeat steps 3,4,5,6,7 with different voltage variations.

B. Lamp brand variation general measurement.

1. Install the lamp in the fitting in the middle of the room. 2. Turn on power supply and adjust power supply at 220 V 3. Make sure the light in the room only come from the lamp. 4. The measurement will take place at 12 points that have been decided.




5. Adjust the position of luxmeter at the first point with 1 meter distance above

ground. 6. Make sure the light that caught by luxmeter sensor is not covered by shadow 7. Turn on the luxmeter, open the sensor cover and note the value on the luxmeter. 8. Repeat steps 5,6, and 7 until the 12th point. 9. Repeat steps 1-8 to each different lamp brands.

C. General measurement of lamp type variation

1. Install the lamp in the fitting in the middle of the room.

2. Turn on power supply and adjust power supply at 220 V

3. Make sure the light in the room only come from the lamp.

4. The measurement will take place at 12 points that have been decided.

5. Adjust the position of luxmeter at the first point with 1 meter distance above ground.

6. Make sure the light that caught by luxmeter sensor is not covered by shadow

7. Turn on the luxmeter, open the sensor cover and note the value on the luxmeter.

8. Repeat steps 5,6, and 7 until the 12th point.

9. Repeat steps 1-8 to each different lamp type




MODULE 6

GROUNDING RESISTANCE MEASUREMENT

I. OBJECTIVE

1. Knowing the amount of grounding resistance of a place.

2. Knowing and understanding the function and usage of grounding resistance measurement

and its application daily.

3. Knowing the earth ground tester working principle

II. BASIC THEORY

Grounding resistance is a resistance of a grounding system that aims to divert lightning

current to the ground so there will be no loss happened due to grounding current. The aim of

grounding: a. Safety and security

b. The tunnel for leakage current

c. Protection of device.

In an electrical installation, there are four parts that need to be grounded, they are: a. Every installation part that is made from conductor (metal) and can be easily touched by

human. This is necessary so that the potential of those metals will always be the same

with ground potential, where human stands, so it is not going to be dangerous for human

to touch it.

b. The lower part of lightning arrester.

This is necessary so lighting arrester can function well, which is to divert the electricity

from lightning to the ground directly.




c. The lightning rod on the upper part of transmission line.

This rod acts as lightning arrester. Since it is located along the transmission line, all of the

legs of transmission poles has to be grounded so the lightning can be diverted to the ground

via the poles’ legs.

d. Neutral point of transformer or generator.

This relates with the protection necessity.

Lightning happens due to potential difference between cloud and earth or between cloud and

another cloud. If the potential difference between cloud and ground is huge, there will be an

electron disposal from cloud to ground or vice versa, to reach equilibrium. The mechanism of

lightning is started by downward leader. This movement will reach the ground, so the negative

charge brought by downward leader will increase positive charge induction on ground surface.

Then the positive charge in a huge amount will move upward by upward leader, responding

downward leader movement, and a contact from the two happens, as a lightning.

Grounding system is related to lightning protection. Lightnng protection is dvided into: a. Internal protection system

Its objective is to protect objects from indirect lightning flash which is magnetic

field induction. Here are the types of internal protection system: 1. Bonding 2. Surge Protection Devices 3. Shielding 4. Safe Distance

b. External protection system

External protection system is used to protect object from direct lightning flash. The types are:




A. Dissipation Array System (DAS)

Dissipation Array System enables lightning flash not to happen in a location.

Point discharge that has sharp point is placed in several places of buildings’ roof, to

move electric charge of that object to air. The charge released by point discharge will

decrease the potential difference between ground and cloud, and reducing the cloud’s

ability to release charge to earth.

B. Charge Transfer System (CTS)

Charge Transfer System is the most common external lightning protection. In

this system, lightning will strike but the position of the strike had been predicted, so it

will not strike the other parts. The methods of CTS are: 1. Franklin Rod 2. Faraday Cage 3. Radioactive (Early Streamer Emission Air Terminal)

In grounding system, several important parts are: a. Air terminal b. Down conductor c. Grounding electrodes d. The soil

The wellness of grounding system is determined

by the amount of grounding resistance, where the

value will influence the grounding resistance.

The standard for good grounding is not more than

5 Ohm.

Factors that influenced grounding resistance value: a. Soil condition b. Humidity

Figure 1. Grounding System




c. Type of soil d. The depth of electrode e. Type of grounding electrode f. Area of down conductor g. Temperature

h. Air terminal type

To reduce the grounding resistance value: a. Paralelling grounding electrodes b. Changing the grounding electrode type c. Creating pool to make the soil humid d. Adding salt to the ground e. Increasing the depth of grounding electrodes

There are two methods to measure grounding resistance of a location

a Four electrode method

The grounding resistance measurement with this method need these equipments:

1. 4 steel rod

2. 1 Amperemeter

3. 1 AC power supply voltmeter

Configuration:

4 steel rod (C1, P1,P2,C2) are mounted to the ground on the same line with

distance to one another of a meter. Between P1 and P2, voltmeter is placed and between

C1 and C2, amperemeter and 110 AC/220 VAC power supply are connected, like below:




Figure 2. Four points method

Measurement method:

Connecting power supply, measuring how many amperes of current flowing

between C1 and C2, say I Ampere. Then measuring how many potential difference between

P1 and P2, say V (volt). Insert all of them in: Rho = 2 π a R where π = 3,14 a = distance between steel rod R=V/I

b. Three-point method

Three point method is the other method to measure grounding resistance. Let’s

say there are 3 grounding rods; rod 1 is the one which want to be measured, and the rest

are the helpers for the measurement. The configuration is below:

Figure 3. Three point method

Earth Ground Tester is a device to measure resistance value of a grounding.





1. Earth Tester Metroohm 2. Connecting cables 3. Grounding nails 4. Hammer

Figure 4. Earth Tester Figure 5. Ports of Earth Tester


Figure 6. Experiment circuit





1. Preparing all the equipment needed 2. Clipping 2 connecting cables to down conductor 3. Placing the end of the two cables to Earth Tester at port C1 and P1 4. Mounting the nails to the ground with the straight line of distance of 5 or 10 meter (first

experiment uses 5m, second uses 10m) from down conductor, about ¾ of nails height deep.

5. Clipping the connector cable to the nails and putting the end of the cable to P1 at earth

tester.

6. Mounting the grounding nail to the ground with 5 meter distance from P1 nail (has to be

on a straight line), ¾ of the nails deep. 7. Clipping the connector cable to the grounding nails and putting the end of the cable to C1

earth tester. 8. Make sure the cables are properly connected. 9. Turning on the earth tester, put the range of earth tester at 20 ohm. 10. Press test button, and note the value shown on earth tester as the grounding

resistance of that area.




MODULE 7

ENERGY CONSUMPTION MEASUREMENT

I. OBJECTIVE

1. Understanding how kWh meter works. 2. Knowing the difference of analog kWh meter and digital kWh meter. 3. Knowing the advantages and drawbacks of each type of kWh meter.

II. BASIC THEORY

Energy is the amount of power consumed in a certain time. kWh meter is the tool used

to measure the power consumption on a consumer. kWh meter is basically divided as analog

type and digital type:

On analog kWh meter:

Figure 1. Analog kWh meter structure

On this analog kWh meter, basically there are 4 parts; driving system, moving system,

braking system and registering system.




a. Driving System

This part is consisted of 2 electromagnets called as shunt magnet and series magnet.

The voltage coil that is connected with supply is put in the center of shunt magnet. The

current coil is in series with load. The coil will carry load’s current and producing

proportional flux with load’s current.

b. Moving System

The moving system in analog kWh meter consists of aluminum plate that is

perpendicular with the rotating axis. The shaft of this plate is connected with the hand in

the front part of kWh meter to show the information of energy consumption. The aluminum

plate is driven by torque coming from magnetic field that is inducted from eddy current in

aluminum plate.

c. Braking System

The braking system in analog kWh meter is controlled by a permanent magnet that

is located across the driving system’s magnet. This permanent magnet will create magnetic

field that opposes the direction of magnetic field that drives aluminum plate and as a result,

braking torque happens.

d. Registering System

The registering system consist of a gear that directly interact with aluminum plate

and hand on kWh meter to show the number, hence the amount of plate rotation will be

read.

In digital kWh meter, the working principle uses microprocessor to get the value of energy

consumption. In this type, the measurement is more accurate. But this kWh meter has more complex

component such as IC, display, voltage sensors, etc. The components of digital kWh meter is:

1. Board / IC

2. Display

3. Voltage and current sensor

4. Voltage and current transformer




5. Port I / O

Here is the flowchart of process in digital kWh meter:

Figure 2. The flowchart of process in digital kWh meter


1. Analog KWh meter 2. Cables 3. Digital wattmeter 4. Lamp Fitting 5. 10 100 W lamps


Figure 3. Experiment Circuit





1. Setting up the circuit as had been shown on the module.

2. Noting the initial value of kWh meter

3. Activating AC source

4. Waiting for 1 hour

5. Noting the result of kWh meter’s measurement

6. Comparing data from kWh meter, length of experiment, load power and the reading of

wattmeter.




MODULE 8

POST TEST

Post test is a final test on all the materials during the Electrical Measurement laboratory activity.

All students taking this course must take the post test and it will be included in the final scoring. The

time and the place of post test will be informed later on.

Documents

LABORATORY MODULES ELECTRICAL MEASUREMENT · Power in electrical engineering, is defined as the amount of electrical energy that is transferred in an electrical circuit in a time