2. Chapter 30 Electrical Wiring

3. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Define basic electrical terms. Explain what is included in an electrical wiring system. List the tools, devices, and materials required to do electrical wiring in a residential building. Demonstrate the proper use of tools and handling of materials. Objectives

4. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Demonstrate an understanding of basic circuit theory. Use approved methods for simple wiring installation tasks. Perform simple electrical troubleshooting. Describe the components of a home security alarm system. Objectives (Cont.)

5. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Building is constructed and closed in Then mechanical systems are installed –Electrical wiring –Plumbing –Heating/ventilating/air conditioning (HVAC) Electricity can be extremely dangerous Qualified electrician must install electrical wiring according to national and local codes Mechanical Systems

6. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Tools and Equipment Proper tools, equipment, and materials are essential when installing electrical wiring –Hammers –Saws and wood chisels –Pliers –Tape measures –Circuit testers

7. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Electrical System Components Circuit is path through which current flows Conductors are wires that carry current Boxes and box covers enclose devices that control electric current Circuit breakers and fuses protect conductors from overload

8. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Ground-Fault Circuit Interrupter Safety device installed as protection against electrical shock May be built into circuit breakers or receptacles Required by electrical code for some areas of home

9. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Arc-Fault Circuit Interrupter Electrical safety device helps prevent houses from catching fire Monitors circuit and detects erratic forms of current Detects arcing and stops all current before fire is started

10. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Switches and Receptacles Various types are used in residential and light commercial applications Switches control current to lights and appliances Receptacles (outlets) allow connection of appliances and lights to circuits

11. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Conduits Pipes or enclosed channels through which conductors are run Made of steel or PVC rigid tubing Lengths can be cut and bent to fit space Wire nuts form sound connection between conductors

12. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Electricity is generated when metal conductor is passed through magnetic field Alternating current (ac) is form of electric current found in homes Direct current (dc) is another form used for other purposes Basic Electrical Wiring Theory

13. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Electric Power Stations Alternating current is generated at electric power stations It travels through transmission lines Transformers are used to increase or decrease voltage

14. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Kinds of Transformers Substations serve whole areas, such as towns Distribution transformers serve one residence or group Small transformers are used within houses to reduce current Service brings electricity to residence Dauphin Island

15. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Electrical current can be extremely dangerous –Make certain circuit is off before working on it –Use only tools with insulated handles –Remove all jewelry and other metal objects –Keep work areas dry and clean –Wear rubber boots or rubber-soled shoes –Use only wood or fiberglass ladders –Wear safety glasses when using striking tools Safety Note

16. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Installing Service Electrical service consists of conductors that bring power from transformer to building Entrance panel houses main breaker and circuit breaker or fuse for each of home’s circuits

17. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Three-Wire Service to Building

18. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. When current-carrying conductor contacts path to ground, ground fault occurs Person coming in contact with unintended current path may get dangerous shock Proper grounding will minimize possibility of short circuit causing shock In properly grounded circuit, every device is connected to ground Ground Faults

19. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Grounding Conductors or ground wire provide path for current to neutral bar in service panel Neutral bus bar is connected to grounding bus bar in service panel Grounding completed by connecting grounding bus bar to grounding electrode

20. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Reading Prints Symbols on electrical prints show conductors and devices to install at each location Electrical print symbols are standardized Electrician may draw wiring layout for each room

21. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Circuit is path from source of power, through energy- using devices, back to power source Circuit Path

22. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Running Branch Circuits Branch circuits include all loads on one run of conductors Conductors are run to each box and securely connected Electrical cables must be securely fastened to framing members

23. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Device Wiring To connect wires to one another –Strip several inches of jacket away –Strip insulation from about 5/8″ of conductors –Twist bare wires together –Install wire nut around twisted wires

24. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Connecting Switches Terminal connections are usually screws Screws are tightened to grip conductors Single pole switch is simple to wire Three-way and four-way switches can be more complicated

25. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Connecting Receptacles Receptacles allow transfer of electrical energy from circuit conductors to devices Hot wire is attached to copper-colored terminal Neutral (white) wire is attached to lighter, silver- colored terminal

26. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Electrical Troubleshooting Problems often involve –Receptacles, switches –Lighting fixtures –Circuit breakers, fuses Complex problems –Open circuits –Broken conductors –Voltage fluctuation –Ground faults

27. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Testing Receptacles Insert leads of circuit tester into receptacle If tester does not light, check line conductors Check for voltage at terminals of receptacle Test for open neutral Check other receptacles on circuit

28. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Testing Fixtures Check to see that switch is on Place probes of circuit tester onto supply conductors If tester lights, voltage is present Repair or replace fixture

29. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Installing wiring is most efficient when walls are still open Most installations are done in new homes or as part of major remodeling projects Building “smart houses” with advanced communication and automation features is growing trend Home Security and Automation Wiring

30. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Installation of home security system wiring is relatively simple System typically includes phone connection to monitoring agency or police and fire stations Home Security Installation

31. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. More complex than home security installation Wiring distribution panels and runs of multiple cables are used Several types of wiring are used –Twisted-pair cables –Shielded coaxial cable –Fiber optic cables Specialized subcontractors usually install security system wiring and structured wiring Home Automation Wiring

32. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Install structured wiring after electrical and plumbing work are done Set up all wiring as home runs Place distribution panel in accessible location Use two or more distribution panels in larger homes Carefully label every cable in panel General Considerations

33. Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Careers Electricians Install electrical systems in new or existing structures Work in construction or maintenance roles Learn by completing apprenticeship and on-job training Lisa F. Young/Shutterstock