INSTALLATION AND MAINTENANCE OF ELECTRICAL EQUIPMENT

LEARNING OUTCOMES

After undergoing the subject, students will be able to:

In his career as a supervisor, an electrical engineering technician will be called upon to inspect,test and modify the work done by skilled workers or artisans working under him. Many a times it willbecome necessary for him to demonstrate the correct method and procedure of doing certainoperations. Normally manufacturers of heavy electrical equipment provide service manuals,instructions for installation, maintenance and fault location. Indian Electricity Rules and IndianStandard Specifications also provide enough guidelines.This syllabus has been designed to provide certain guidelines and broad principles regarding theabove activities. Appropriate field trips will reinforce the learning.

CHAPTER- 1

Tools and Accessories Tools, accessories and instruments required for installation, maintenance and repair workKnowledge of Indian Electricity rules, safety codes, causes and prevention of accidents,artificial respiration of an electrocuted person, workmen's safety devices Tools, accessories and instruments required for installation

Tape Measure.

Multimeter.

Wire Stripper.

Fish tape.

Non-contact Voltage Detector.

Plier.

Level.

Flashlight.

1. Tape Measure

A must-have for beginners and pro electricians alike, a tape measure is essential for measuring

heights for switch and outlet placement, centering lighting fixtures and so much more. For under

$15 we recommend Lufkin self-centering tape, clear-coated blade protection for more durable

markings and designed to fit comfortably in hand.

2. Multimeter

Checking voltages and current is critical to any electrical job. A multimeter is an important

all-in-one tester used to measure voltages, current and resistance in an electrical circuit and can

help you locate power fluctuation causes like shoddy wiring. Klein Tools offers some budget and

pro multimeters to suit your needs. For serious electricians we recommend the Klein Tools

MM5000 Electrician’s TRMS Multimeter.

3. Wire Stripper

A handy tool to strip or cut off the insulation on wires. A good quality wire stripper will do a clean

job every time and is designed with a cutoff portion and various sized cutting teeth for different

sized wires or cable. Top models include ergonomically designed handles requiring less hand

force and curved cutting blades to ensure cleaner, precise cuts. We offer many quality wire

stripper options you can choose from starting as low as $10.

4. Fish tape

Also known as draw wire/tape, fish tapeis used by electricians to route new wiring through walls,

metal, electrical and PVC conduit. We recommend Wide Steel Fish Tape by Klein Tools–

available in different lengths along with Klein cable lube to assist in guiding the tape through

narrow spaces.

5. Non-contact Voltage Detector

There’ll be many times you’ll need to do a quick safety check to see if there is a current present or

a circuit is indeed live. A voltage detector is either automatic or has an on/off switch. Pick the one

that suits your budget and needs. We recommend the Klein voltage tester; a durable tester that will

provide accurate test readings and a long service life on the job-site, in the shop and at home. At

under $20 we recommend the Klein Tools NCVT-2 Dual Range Non-Contact Voltage Tester

.

6. Plier

Pliers come in many types depending on what needs to done. For example, side-cutting or

diagonal pliers are specially designed for wire cutting. Their cutting edge goes to the tip of the

pliers and comes in handy to trim wires in tight spaces. You’ll also need a quality set of do-it-all

pliers. These can cut wire, twist wires together using their squared off tip and grip and pull wire.

We carry a wide range of pliers for any job at hand.

7. Level

A great installation starts with getting the basics right. A level is used to make sure all your work is

level including straight outlet covers, wall plates and switches. For just over $5 the hands-free

magnetic Torpedo level is a steal. Lightweight and compact, it provides accurate readings,

including horizontal, vertical and at 45-degree angles.

8. Flashlight

Any pro electrician will tell you that proper lighting is key to any electrical job, and that you

should never try and reach into a panel without proper lighting. When lighting conditions on the

job site are not the best, a good flashlight or work light can save the day. We offer over 50 types of

flashlights to fulfill any lighting need in any space.

Maintenance and repair workKnowledge of Indian Electricity rules

Indian Electricity Rules, 2005 defines the basic fundamentals of Electricity Safety, and when

followed in totality there cannot be any incidence of electrocution or electric fire.

General Safety requirements are given in Chapter IV under rules 29 to 46 which covers

installation, protection, operation, maintenance cut-out, identification of earth, earthed terminal,

danger notice etc.

General Rule 29 covers installation shall be constructed, installed, protected, worked and

maintained in accordance with BIS. It further stipulates that the material and equipment used shall

conform to the relevant specifications of the BIS.

The National Electrical Code issued by BIS states in Clause 3.1.3.6 that the current rating of a

fuse shall not exceed the current rating of the smallest cable in the circuit protected by the fuse.

Workmen's safety devices

Depending on the job task to be performed, PPE for the electric power industry generally includes

safety glasses, face shields, hard hats, safety shoes, insulating (rubber) gloves with leather

protectors, insulating sleeves, and flame-resistant (FR) clothing.

Safety codes

In the field of electrical engineering, engineers and other professionals get exposed to electricity

indirectly during generation, transportation, installation and usage. Such conditions might cause

hazards if accurate safety measures are not taken.

To promote the safety and the right usage of equipment, there are certain rules and regulations

formulated by the Bureau of Indian Standards (BIS). BIS follows the following five principles −

Safety

Ease of use and adaptability

Simple technology

Value for money products

Energy efficiency and environment

BIS has published the following code of practice for public safety standards in order to promote

the right to information, transparency and accountability in a proper manner to the public.

CHAPTER-2

Installation

2.1 Domestic Installation 2.1.1 Introduction 2.2.2 Testing of electrical installation of a building a) Testing of insulation resistance to earth b) Testing of insulation and resistance between conductors

c) Continuity or open circuit test

Domestic Installation

Homes typically have several kinds of home wiring, including Electrical wiring for lighting and

power distribution, permanently installed and portable appliances, telephone, heating or

ventilation system control, and increasingly for home theatre and computer networks. [1]

Safety regulations for wiring installation vary widely around the world, with national, regional,

and municipal rules sometimes in effect. Some places allow the homeowner to install some or all

of the wiring in a home; other jurisdictions require electrical wiring to be installed by licensed

electricians only.

2.1.1 Introduction Industrial electrical systems require proper installation, operation and maintenance of equipment for a facility to operate safely and efficiently. Of the many types of electrical installations, those in hazardous areas are likely the most difficult to deal with. Misunderstanding or misinterpretations can easily lead to unsafe conditions that put personnel and facilities at risk. This presentation discusses the critical elements for maintaining various types of hazardous location equipment. Class I, Divisions 1 & 2 and Class I, Zones 0, 1, & 2 concepts will be discussed. Class II and Class III hazardous locations are not addressed in this paper.

2.2.2 Testing of electrical installation of a building

Kinds of Electrical Installation Testing

1. Electrical Wiring Continuity Testing. ...

2. Electrical Insulation Resistance Testing. ...

3. Electrical Earth Continuity Path Testing. ...

4. Electrical Testing of Non-linked Single Pole Switches. ...

5. Electrical Earth Resistivity Testing. ...

6. Electrical Performance Testing.

1. Electrical Wiring Continuity Testing

All wiring system shall be tested for continuity of circuits, short circuits and earthing after wiring

is completed and before energizing.

2. Electrical Insulation Resistance Testing

The insulation resistance shall be measured across earth and the whole system of conductors, or

any section thereof, with all fuses in place and all switches closed and except in concentric wiring

all lamps in position of both poles of the installation otherwise electrically connected together.

A direct current pressure of not less than twice the working pressure provided that it does not

exceed 660 V for medium voltage circuits. Where the supply is divided from AC three phase

system, the neutral pole of which is connected to earth, either direct or through added resistance,

pressure shall be deemed to be that which is maintained between the phase conductor and the

neutral.

3. Electrical Earth Continuity Path Testing

The earth continuity conductor metallic envelops of cables, shall be tested for electric continuity

and the electrical resistance of the same along with the earthing lead but excluding any added

resistance or earth leakage circuit breaker measured from the connection with the earth electrode

to any point in the earth continuity conductor in the completed installation shall not exceed one

ohm.

4. Electrical Testing of Non-linked Single Pole Switches

In a two wire installation a test shall be made to verify that all non linked single pole switches have

been fitted in the same conductor throughout, and such conductor shall be labeled or marked for

connection, throughout, and such conductor shall be labeled or marked for connection to an outer

or phase conductor or non earthed conductor a test shall be made three or four wire installation a

test shall be made to verify that every non linked single pole switch is fitted in a conductor to one

of the outer or phase conductor of the supply. The entire electrical installation shall be subject to

the final acceptance of the Supervising engineer as well as the local authorities.

5. Electrical Earth Resistivity Testing

Earth resistivity test shall be carried out in accordance with British Standard Code of Practice of

Earthing. All tests shall be carried out in the presence of the Supervising Engineer.

6. Electrical Performance Testing

The complete electrical installation and equipment shall be subject to the final performance test as

intended for each and every equipment shall be tested as per the manufacturers instructions.

2.2 Installation of transmission and Distribution Lines

Transmission

To move our electricity from power generating facilities to local areas, ENMAX Power

Corporation relies on a system of high-voltage power lines across Alberta, including our own 299

km network within the city. These transmission lines enter a substation where a transformer

reduces voltage to a level that can be safely delivered to customers.

Distribution

In Calgary, once the electricity is delivered to one of our 40 substations, low voltage power lines

transport electricity over short distances to distribute the power to local homes and businesses. To

accomplish this, ENMAX Power Corporation uses 8,301 km of distribution lines in Calgary and

surrounding area.

Although it is not a regulatory requirement, ENMAX Power makes every effort to notify residents

of distribution projects that may impact their communities.

2.3 Installation of Underground Cables:

Direct laying of underground cables

1. A trench of about 1.5 meters deep and 45 cm wide is dug.

2. Then the trench is covered with a 10 cm thick layer of fine sand.

3. The cable is laid over the sand bed. ...

4. Then the laid cable is again covered with a layer of sand of about 10 cm thick.

2.4 Installation of Transformers

Provide proper clearance for cable and avoid installing them near blades or coils. Follow

minimum wire bending space clearances at terminals for conductors per NEC. If required, follow

NEMA standards for transformer sound control depending upon the kVA rating of a unit.

2.5 Installation of Substations

1. Establish the work zone.

2. Prepare the substation site.

3. Excavate and lay the foundations.

4. Install the grounding grid.

5. Build the command building.

6. Backfill the foundations and substation yard.

7. Assemble the steel structures.

8. Install the electrical equipment.

2.6 Installation of Motors and Generators

Electrical motors and generators are machines which either convert electrical energy inputs into

forces or applied kinetic energy inputs into electrical energy. In principle, any electrical generator

can also be operated as a motor and vice-versa. In practice they will often be optimized for one

application or the other.

All electrical machines operate due the same principles derived from the study of

electro-magnetics. Therefore, it is appropriate to first discuss these underlying electromagnetic

concepts as this is crucial for understanding their operation. However, before discussing these

concepts it will also be useful to revise the concepts of vector algebra and vector calculus which

are used extensively in this subject.

CHAPTER-3

Maintenance

3.1 Definition and types of maintenance, maintenance schedules, procedures

Traditionally, 5 types of maintenance have been distinguished, which are differentiated by the

nature of the tasks that they include:

Corrective maintenance: The set of tasks is destined to correct the defects to be found in the

different equipment and that are communicated to the maintenance department by users of

the same equipment.

Preventive Maintenance: Its mission is to maintain a level of certain service on equipment,

programming the interventions of their vulnerabilities in the most opportune time. It is

used to be a systematic character, that is, the equipment is inspected even if it has not given

any symptoms of having a problem.

Predictive Maintenance: It pursues constantly know and report the status and operational

capacity of the installations by knowing the values of certain variables, which represent

such state and operational ability. To apply this maintenance, it is necessary to identify

physical variables (temperature, vibration, power consumption, etc.). Which variation is

indicative of problems that may be appearing on the equipment. This maintenance it is the

most technical, since it requires advanced technical resources, and at times of strong

mathematical, physical and / or technical knowledge.

Zero Hours Maintenance (Overhaul): The set of tasks whose goal is to review the

equipment at scheduled intervals before appearing any failure, either when the reliability of

the equipment has decreased considerably so it is risky to make forecasts of production

capacity . This review is based on leaving the equipment to zero hours of operation, that is,

as if the equipment were new. These reviews will replace or repair all items subject to

wear. The aim is to ensure, with high probability, a good working time fixed in advance.

Periodic maintenance (Time Based Maintenance TBM): the basic maintenance of

equipment made by the users of it. It consists of a series of elementary tasks (data

collections, visual inspections, cleaning, lubrication, retightening screws,…) for which no

extensive training is necessary, but perhaps only a brief training. This type of maintenance

is the based on TPM (Total Productive Maintenance).

3.2 Maintenance of Transmission and Distribution System

T&D System Overview

Explain how power grids help ensure a continuous flow of power to customers.

State the purpose of a T&D system.

Describe the major components of a T&D system.

Power Plants

State the function of a power plant.

Describe the general characteristics of atypical power plant.

Switchyards

State the general function of switchyard.

Describe the major components of a typical switchyard.

Describe how the electrical flow path through a switchyard can be altered to isolate certain

equipment.

Transmission Lines

Explain the function of transmission lines in a typical T&D system.

Describe the major components of transmission lines.

Substations

Explain the function of a substation.

Describe the components of a typical substation.

Describe how the electrical flow path through a substation can be altered to isolate certain

equipment.

Distribution

Explain the function of a distribution system.

Describe the major components of a typical distribution system.

Explain how electricity travels through a typical distribution system to reach customers.

3.3 Maintenance of Distribution Transformers

Distribution transformers are normally considered to be those transformers which provide the

transformation from 11 kV and lower voltages down to the level of the final distribution network.

In the UK this was, until January 1995, 415 V three-phase and 240 V phase to neutral.

Now it is nominally 400 V three-phase and 230 V between phase and neutral. Of course, these

are nominal voltages to be applied at consumers’ terminals and there are tolerances to take account

of light loading conditions and regulation at times of peak load.

Prior to January 1995, most distribution transformers were designed for a secondary open-circuit

voltage on principal tapping of 433 V and it remains to be seen whether this situation will change

in the long term.

At the present time, however, transformer voltage ratios have not changed, although it is possible

that some adjustment of transformer off-circuit tappings might have been made at some points of

the distribution network.

3.4 Maintenance of Grid Substations

Substation maintenance is a process of periodic, planned inspection of and, if necessary, repair, and replacement of all switchgear, buildings, and ancillary equipment in substation installations. ... Substations are the most critical part of any electrical supply grid.

3.5 Maintenance of Motors

A well-planned electric motor preventive maintenance programme is the key to dependable,

long-life operation of electric motors.

Almost all electrical equipment requires planned inspection and maintenance being carrying out.

This ensures electrical equipment is kept in good working condition at all times. This is critical for

electric motors. Routine motor inspections should be carried out at scheduled times throughout the

motor’s life. Periodic inspections prevent serious damage to machinery by locating potential

problems.

Electric motor maintenance programmes aim to prevent critical breakdowns rather than repairing

them. In plant operations, unscheduled stoppage of production or long repair shutdowns are

intolerable. The resultant downtime eats deeply into production times. Periodic inspections of

motors are necessary to ensure best operating results.

Preventative maintenance programmes require detailed checks, and all motors onsite should be

given an ID number and have a record log. The motor records should identify the motor, brand,

inspection dates and descriptions of repairs. By keeping records, the cause of any breakdowns can

determine the fault and reduce on-going problems.

All maintenance programmes should refer to the manufacturer’s techincal documentation prior to

performing checks.

There are simple routine and maintenance checks for three phase motors which can aid in and

ensure a long life to a motor. Simple checks would be reviewing the service history, noise and

vibration inspections. This would also include visual inspections, windings tests, brush and

commutator maintenance and bearings and lubrication.

Inspection and servicing should be systematic. The frequency of inspections and the degree of

thoroughness may vary depending on such factors as the importance of the motor, it’s usage and

the motor’s environment. An inspection schedule, therefore, must be flexible and adapted to the

.needs of each plant.

Frequent checks

1. Clean motor of any dust or oil.

2. Check oil rings turn with shaft.

3. Check oil level in bearings.

4. Visually check for oil and grease from bearings.

5. Technician to examine the starter switch, fuses and tighten loose connections.

Every 6 months

1. Clean motor, blowing out dirt from windings, and wipe commutator and brushes.

2. Visually inspect commutator clamping ring.

3. Check and replace brushes that are more than half worn.

4. Examine brush holders, and clean them if dirty.

5. Check brush pressure and position.

6. Remove, clean out, and replace oil in sleeve bearings.

7. Check grease in ball or roller bearings.

8. Check operating speed or speeds.

9. Technician to examine and tighten loose connections.

10. Test current input and compare it with normal.

11. Visually check drive, for smooth running, absence of vibration.

12. Check motor foot bolts.

Annually

1. Remove and renew grease in ball or roller bearing.

2. Test insulation.

3. Clean out magnetic dirt that may be attached to poles.

4. Check clearance between shaft and journal boxes of sleeve bearing motors.

5. Check the commutator for smoothness and slot damage.

6. Examine connections of commutator and armature coils.

7. Inspect armature bands.