1. ELECTRICAL WIRING WIRING BASICS Written by Bobby Joslin
GA Ag Ed Curriculum Office
To accompany the Georgia Agriculture Curriculum Lesson
July 2002

2. STANDARDS FOR SAFETY National Electrical Code Local Electrical Code
Power Company Requirements
Underwriters Laboratory (UL)

3. NATIONAL ELECTRICAL CODE
History of the National Electrical Code
Purpose of the NEC
How Often the NEC is updated
Scope of the NEC
Enforcement of the NEC
Using the NEC

4. LOCAL ELECTRICAL CODES
Local authorities may adopt NEC
May adopt NEC with modifications
Local wiring permits and inspections

5. POWER COMPANY REQUIREMENTS

6. UNDERWRITERS LABORATORY
UL Listed assures product meets minimum safety standards
UL Listed does not mean that product is safe for all installations
UL Listed is not an indication of quality

7. BRANCH CIRCUITS
Definition of circuit
Definition of branch circuit

8. BRANCH CIRCUITS IN A RESIDENCE
Individual Circuit
Small Appliance Circuit
Laundry Circuit
Bathroom Circuit
General Purpose Circuit

9. INDIVIDUAL CIRCUIT Supplies only one outlet or piece of equipment
Motors 1/2 horsepower or larger
All 240 volt equipment
Other equipment such as furnace fan, freezer, television, computer

10. SMALL APPLIANCE CIRCUIT
Serves receptacles for small appliance loads
At least two required by NEC
Must be 20 ampere circuits
No lighting outlets
Cannot serve any other room in house

11. LAUNDRY CIRCUIT Serves only receptacles in laundry room
At least one required by NEC
Must be 20 ampere circuit
May not have lighting outlets
May not serve outlets in any other room of house

12. BATHROOM CIRCUIT Circuit to serve receptacles in bathroom
At least one required by NEC
Must be 20 ampere circuit
May not serve lighting outlets
May not serve any other room in house

13. GENERAL PURPOSE CIRCUITS
Serve all lighting outlets in home
Serve all receptacles not on one of the other types of circuits
May be 15 or 20 ampere (20 ampere preferred)
Allow at least one general purpose circuit for every 500 square feet of floor space in house

14. Determining the Kind, Number and Location of Outlets and Switches in a Wiring System

15. Lighting Outlet Requirements
At least one wall switch controlled outlet in every habitable room in house
Stairways consisting of 6 or more steps must have lighting outlet that is wall switch controlled at both floor levels
Attics, underfloor space, utility room and basement requirements

16. RECEPTACLE OUTLET REQUIREMENTS
No point along the floor line in any wall space may be more than 6 feet from a receptacle in kitchen, family room, dining room, living room, den, sun room, bedroom, recreation room, or similar room
(Receptacles must be no farther than _____ feet apart.)

17. RECEPTACLE REQUIREMENTS
A receptacle must be installed at each kitchen and dining area counter space if the space is wider than 12 inches
No point along the wall line of a kitchen counter may be more than 24 inches from a receptacle
(Receptacles must be no farther than _____ inches apart)

18. RECEPTACLE REQUIREMENTS
At least one receptacle is required within 36 inches of the outside edge of each basin in bathrooms.
All receptacles in bathrooms must have ground fault circuit interrupter protection

19. RECEPTACLE REQUIREMENTS
At least one outdoor receptacle is required
All outdoor receptacles must have GFCI protection
Outdoor receptacles must be installed in waterproof boxes

20. RECEPTACLE REQUIREMENTS
At least one receptacle is required in the laundry area
At least one receptacle is required in a basement. All general use receptacles in an unfinished basement must have GFCI protection

21. RECEPTACLE REQUIREMENTS
At least one receptacle is required in hallways 10 feet or more in length
Effective January 1, 2002, all receptacles in a bedroom must have arc-fault circuit interrupter protection

22. RECOMMENDATIONS FOR OUTLETS AND SWITCHES
Receptacles should generally be located approximately above floor line
Receptacles preferably should be located near the ends of wall space
Lighting outlets in closets should be wall switch controlled
Pull chain lighting outlets should be minimized, if used at all

23. RECOMMENDATIONS FOR OUTLETS AND SWITCHES
Wall switches should be generally be located approximately 48 inches above the floor line and on the latch side of doors
Three and four way switches should be used to control lights in locations such as rooms having more than one entrance, stairways, halls, basement, covered walkways between the house and garage, etc.

24. Determining the Number of Outlets On a General Purpose Circuit
For calculation purposes, estimate a load of at least 1.5 amps per outlet on the circuit
To determine the maximum number of outlets on a 20 amp general purpose circuit: 20 amps (circuit rating)  1.5 amps = outlets (maximum) on the circuit
Maximum number of outlets on a 15 amp general purpose circuit = ________?

25. SELECTING SERVICE ENTRANCE EQUIPMENT
Service conductors
Service mast
Entrance head or weather head
Meter base
Service entrance cable

26. Service Entrance Panel
Purpose
Factors to consider when selecting the service entrance panel
Type of panel
Size or ampere rating
Circuit capacity or number of spaces for connecting circuits

27. PROVIDING OVERCURRENT PROTECTION
Providing a means to interrupt an electrical circuit when the amperage in the circuit becomes excessive
Reasons for providing overcurrent protection

28. SIZE OF OVERCURRENT PROTECTION DEVICE TO USE

29. PLANNING ELECTRICAL CIRCUITS
Wiring symbols

30. CLASSIFICATION OF CONDUCTORS
Grounded conductor
Ungrounded conductor
Equipment grounding conductor
Grounding electrode conductor

31. Grounded Conductor
A current carrying conductor that is connected to the earth
Often called the neutral wire
Color must be white or natural gray
Known as identified conductor
Identity must be maintained throughout a circuit and the electrical system

32. Grounded Conductor
NEVER connected to a fuse, circuit breaker, or a switch
One grounded conductor must be connected to all 120 volt outlets or equipment

33. UNGROUNDED CONDUCTOR
A current carrying conductor that is not connected to the earth
Often called the “hot” wire
Color should not be white, gray, or green. Color may be black, red, blue, etc.
Circuit breakers (or fuses) and switches are placed on the ungrounded conductor

34. UNGROUNDED CONDUCTOR
One ungrounded conductor must be connected to all 120 volt outlets or equipment.
Two ungrounded conductors must be connected to all 240 volt outlets or equipment.

35. EQUIPMENT GROUNDING CONDUCTOR
Under normal conditions, the equipment grounding conductor is never a current carrying conductor. It serves as a path to ground if a fault occurs in electrical equipment or the electrical system
May be a bare wire or may have green or green with yellow stripe insulation

36. EQUIPMENT GROUNDING CONDUCTOR
Always connected to the grounding terminal of devices (receptacles, switches, etc.)
Always connected to non-current carrying metal parts of equipment and circuits (including all metal boxes)

37. GROUNDING ELECTRODE CONDUCTOR
The large bare copper wire that connects the electrical system to the grounding electrode
Size is determined by the size of service entrance cable being used

38. COLOR CODING OF ELECTRICAL CONNECTIONS
Silver or white colored terminal - attach the grounded conductor
Copper or brass colored terminal -attach the ungrounded conductor
Green colored terminal - attach the equipment grounding conductor