ELECTRICAL WIRING UNIT LATIHAN DAN PENDIDIKAN LANJUTAN POLITEKNIK SULTAN ABDUL HALIM MU’ADZAM SHAH Prepared by: FAIRUZ ABADI BIN KHALID Pegawai Latihan dan Pendidikan Lanjutan POLITEKNIK SULTAN ABDUL HALIM MU’ADZAM SHAH Kursus Terlanggan (PSH)
DISCLAIMER Publisher: POLITEKNIK SULTAN ABDUL HALIM MU'ADZAM SHAH UNIT LATIHAN DAN PENDIDIKAN LANJUTAN All rights reserved: POLITEKNIK SULTAN ABDUL HALIM MU'ADZAM SHAH UNIT LATIHAN DAN PENDIDIKAN LANJUTAN All rights reserved. No part of this publication may be produced, stored, transmitted in any form or by any electronic, mechanical, photocopying, recording, or otherwise without prior permission of author/s or publisher. The authors also do not guarantee that the content is suitable for the reader, but all the content is through the author’s own experience and expertise. ELECTRICAL WIRING FAIRUZ ABADI BIN KHALID Publisher: POLITEKNIK SULTAN ABDUL HALIM MU'ADZAM SHAH UNIT LATIHAN DAN PENDIDIKAN LANJUTAN BANDAR DARULAMAN 06000 JITRA KEDAH TEL: 049146100 FAX: 049174232 Cataloguing-in-Publication Data Perpustakaan Negara Malaysia A catalogue record for this book is available from the National Library of Malaysia eISBN 978-967-0055-51-0
Subscription Course Handbook (Electrical Wiring) This book is published as a guide and reference for basic wiring course participants under Lifelong Learning Training (PSH), This book also contains explanation notes along with examples of real diagrams from aspects of safety, equipment, wiring methods, protection and testing. ULPL POLIMAS SUBSCRIBE COURSE NOTES ELECTRICAL WIRING LIFELONG LEARNING PROGRAM (PSH) ACKNOWLEDGEMENTS
TABLE OF CONTENTS NO TITLE PAGES 1 TOPIC 1 – ELECTRICAL SAFETY 1 2 TOPIC 2 – ACCESSORIES AND TOOLS IN ELECTRICAL INSTALLATION 35 3 TOPIC 3 – WIRING SYSTEM 67 4 TOPIC 4 – WIRING PROTECTION 86 5 TOPIC 5 – INSPECTION AND TESTING 100
ELECTRICAL WIRING TOPIC 1 – ELECTRICAL SAFETY COURSE LEARNING OUTCOME Upon completion of this course, participants should be able to: 1.Apply the concept and principle of electrical safety and regulation in performing electrical wiring according to NIOSH and MS IEC 60364 standard. 6
1.0 ELECTRICAL SAFETY Hazards in wiring installation a) Old wiring. b) Wire gage insufficient for loads c) Non-grounded or improperly polarized plugs and outlets d) Fuse or circuit-breaker misuse e) Not enough branch circuits and outlets f) No AFCI’s in critical areas g) No GFCI in bathrooms or kitchens, outdoors, or near swimming pools h) Failing aluminum wiring connections i) Excessive attic temperatures j) Overloaded or damaged extension cords 7
Hazard in faulty electrical parts Electrical accidents are caused by a combination of three factors: – Unsafe equipment and/or installation, – Workplaces made unsafe by the environment, and – Unsafe work practices. 8
EXPOSED ELECTRICAL PARTS Cover removed from wiring or breaker box 9
Hazard of overhead power lines • Usually not insulated • Examples of equipment that can contact power lines: – Crane – Ladder – Scaffold – Backhoe – Scissors lift – Raised dump truck bed – Aluminum paint roller 10
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Improper Grounding Hazards • Tools plugged into improperly grounded circuits may become energized • Broken wire or plug on extension cord • Some of the most frequently violated OSHA standards 12
Overload Hazard Overloads in an electrical system are hazardous because they can produce heat or arcing. Wires and other components in an electrical system or circuit have a maximum amount of current they can carry safely. If too many devices are plugged into a circuit, the electrical current will heat the wires to a very high temperature. If any one tool uses too much current, the wires will heat up Overloads are a major cause of fires. Damaged equipment can overheat and cause a fire 13
Wet condition hazard • If you touch a live wire or other electrical component while standing in even a small puddle of water you’ll get a shock. • Damaged insulation, equipment, or tools can expose you to live electrical parts. • Improperly grounded metal switch plates & ceiling lights are especially hazardous in wet conditions. • Wet clothing, high humidity, and perspiration increase your chances of being electrocuted. 14
Additional Hazards In addition to electrical hazards, other types of hazards are present at job sites. Remember that all of these hazards can be controlled. • There may be chemical hazards. Solvents and other substances may be poisonous or cause disease. • Frequent overhead work can cause tendinitis (inflammation) in your shoulders. • Intensive use of hand tools that involve force or twisting can cause tendinitis of the hands, wrists, or elbows. Use of hand tools can also cause carpal tunnel syndrome, which results when nerves in the wrist are damaged by swelling tendons Overhead work can cause long-term shoulder pain. Frequent use of some hand tools can cause wrist problems such as carpal tunnel syndrome. 15
Lock Out and Tag Out circuits and equipment • Apply locks to power source after de-energizing • Tag deactivated controls • Tag de-energized equipment and circuits at all points where they can be energized • Tags must identify equipment or circuits being worked on 16
Overload wiring by using the right size and types of wire • Wire used depends on operation, building materials, electrical load, and environmental factors • Use fixed cords rather than flexible cords • Use the correct extension cord 17
Control • Insulate live wires • Check before use • Use only cords that are 3-wire type • Use only cords marked for hard or extra-hard usage • Use only cords, connection devices, and fittings equipped with strain relief • Remove cords by pulling on the plugs, not the cords • Cords not marked for hard or extra-hard use, or which have been modified, must be taken out of service immediately 18
Live electrical parts by isolation Electrical hazards exist when wires or other electrical parts are exposed. These hazards need to be controlled to create a safe work environment. Isolation of energized electrical parts makes them inaccessible unless tools and special effort are used. Isolation can be accomplished by placing the energized parts at least 8 feet high and out of reach, or by guarding. Guarding is a type of isolation that uses various structures—like cabinets, boxes, screens, barriers, covers, and partitions—to close-off live electrical parts Guarding : a covering or barrier that separates you from live electrical parts 19
Control – Isolate Electrical Parts - Cabinets, Boxes & Fittings Conductors going into them must be protected, and unused openings must be closed 20
Wires and Parts using Insulation • Insulation covers wires and prevents conductors from coming in contact with each other or any other conductor. • If conductors are allowed to make contact, a short circuit is created. • Insulation keeps wires and other conductors from touching, which prevents electrical short circuits. • Insulation prevents live wires from touching people and animals, thus protecting them from electrical shock. 21
Current Shock from electrical systems by Grounding them Grounding creates a path for currents produced by unintended voltages on exposed parts. These currents follow the grounding path, rather than passing through the body of someone who touches the energized equipment 22
Shock Current by Using Ground Fault Circuits • When an electrical system is not grounded properly, a hazard exists. This is because the parts of an electrical wiring system that a person normally touches may be energized, or live, relative to ground. Parts like switch plates, wiring boxes, conduit, cabinets, and lights need to be at 0 volts relative to ground 23
Using Over current Protection devices. When a current exceeds the current rating of equipment or wiring, a hazard exists. The wiring in the circuit, equipment, or tool cannot handle the current without heating up or even melting. Not only will the wiring or tool be damaged, but the high temperature of the conductor can also cause a fire. To prevent this from happening, an overcurrent protection device (circuit breaker or fuse) is used in a circuit. These devices open a circuit automatically if they detect current in excess of the current rating of equipment or wiring. This excess current can be caused by an overload, short circuit, or high-level ground fault. 24
Use overcurrent protection devices (circuit breakers or fuses) in circuits. 25
Apply Working Practices Safety Ladder safety facts sheet. To prevent injury when climbing, follow these procedures: 1. Position the ladder at a safe angle to prevent slipping. The horizontal distance from the base of the ladder to the structure should be one-quarter the length of the ladder. If you don’t have a way to make this measurement, follow the steps below to determine if the ladder is positioned at a safe angle. • Put your feet at the base of the ladder and extend your arms straight out. • If you can touch the closest part of the ladder without bending your arms, the ladder is probably at the correct angle 26
• If you have to bend your arms to touch the closest part of the ladder or if you can’t reach the ladder at all, the ladder is not positioned at a safe angle 2. Make sure the base of the ladder has firm support and the ground or floor is level. Be very careful when placing a ladder on wet, icy, or otherwise slippery surfaces. Special blocking may be needed to prevent slipping in these cases. 3. Follow the manufacturer’s recommendations for proper use. 4. Check the condition of the ladder before using it. Joints must be tight to prevent wobbling or leaning. 27
5. When using a stepladder, make sure it is level and fully open. Always lock the hinges. Do not stand on or above the top step. 28
Avoid Wet Conditions • If you touch a live wire or other electrical component while standing in even a small puddle of water you’ll get a shock. • Damaged insulation, equipment, or tools can expose you to live electrical parts. • Improperly grounded metal switch plates & ceiling lights are especially hazardous in wet conditions. • Wet clothing, high humidity, and perspiration increase your chances of being electrocuted. 29
Safety Procedures to Avoid Overhead Power Lines. • Stay at least 10 feet away • Post warning signs • Assume that lines are energized • Use wood or fiberglass ladders, not metal • Power line workers need special training & PPE 30
Choose Proper Wiring Connector • Use and test GFCI’s • Check switches and insulation • Use three prong plugs • Use extension cords only when necessary & assure in proper condition and right type for job • Use correct connectors 31
Use and Maintain Tools Properly Maintain tools and equipment. Inspect your equipment before use it. • Inspect tools before using them—Check for cracked casings, dents, missing or broken parts, and contamination (oil, moisture, dirt, corrosion). Damaged tools must be removed from service and properly tagged. These tools should not be used until they are repaired and tested. • Use the right tool correctly—Use tools correctly and for their intended purposes. Follow the safety instructions and operating procedures recommended by the manufacturer. When working on a circuit, use approved tools with insulated handles. However, DO NOT USE THESE TOOLS TO WORK ON ENERGIZED CIRCUITS. ALWAYS SHUT OFF AND DE-ENERGIZE CIRCUITS BEFORE BEGINNING WORK ON THEM 32
• Protect your tools—Keep tools and cords away from heat, oil, and sharp objects. These hazards can damage insulation. If a tool or cord heats up, stop using it! Report the condition to a supervisor or instructor immediately. If equipment has been repaired, make sure that it has been tested and certified as safe before using it. Never carry a tool by the cord. Disconnect cords by pulling the plug—not the cord! • Use double-insulated tools—Portable electrical tools are classified by the number of insulation barriers between the electricalconductors in the tool and the worker. The NEC permits the use of portable tools only if they have been approved by Underwriter’s Laboratories (UL Listed). Equipment that has two insulation barriers and no exposed metal parts is called doubleinsulated. When used properly, double-insulated tools provide reliable shock protection without the need for a third ground wire. Power tools with metal housings or only one layer of effective insulation must have a third ground wire and three-prong plug. 33
Use multiple safe practices—Remember: A circuit may not be wired correctly. Wires may contact other “hot” circuits. Someone else may do something to place you in danger. Take all possible precautions. Don’t work on energized circuits like this one! Always follow correct lock-out/tag-out procedures. Use the right tools and equipment. Do not work on energized circuits. 34
TOPIC 2 – ACCESSORIES AND TOOLS IN ELECTRICAL INSTALLATION COURSE LEARNING OUTCOME Upon completion of this course, participants should be able to: 1.Apply the concept and principle of electrical safety and regulation in performing electrical wiring according to NIOSH and MS IEC 60364 standard. 35
2.1 ACCESSORIES AND TOOLS IN ELECTRICAL INSTALLATION Function and installation methods of electrical installation accessories: • Switches • Lamp holders • Outlet sockets • Circuit breakers • Fuses • kWh meters • Distribution boards • Distribution fuse boxes 36
Switch Switch Light (5A) 2 Way Switch (1 pole 2 way) 1 Way Switch (1 pole 1 way) Intermediate Switch(2 pole 2 way) 37
Switch C 1W/L1 (COMMON) (1 WAY/LOAD 1) 1 Way Switch 1 pole 1 way 38
Switch C 2W/L2 (COMMON) (2 WAY/LOAD 2) 1W/L1 (1 WAY/LOAD 1) 2 Way Switch 1 pole 2 way 39
Switch Input from 2 way switch Output from 2 way switch 1W/L1 1W/L1 2W/L2 2W/L2 Intermediate Switch 2 pole 2 way 40
Lamp Holder Pendent Lamp Holder Batten Lamp Holder Ceiling Roses 41
Outlet Sockets Molded box Outlet Sockets 15A Outlet Sockets 13A 42
Outlet Sockets L E N (LIVE) (EARTH) (NEUTRAL) Outlet Socket 13A 43
Earth Leakage Circuit Breaker (ELCB) & Main Switch Main Switch Earth Leakage Circuit Breaker (ELCB) 44
Main Switch Input from meter KWh ELCB output L N L N 45
Earth Leakage Circuit Breaker (ELCB) Input from main switch Output to ELCB L N L N Output to neutral PFA 46
Fuses Metal Ends Glass or ceramic Thin Fuses Wire tube 47
kWh 48
MCB (MCB) 49
MCB Output from switch (common), socket (L) ect From Output ELCB L L 50