1. Lesson Identifying Electrical Tools and Equipment

2. Interest Approach What are each of the following items and how are they used?

3. Pictures by Allen Ritter

4. Student Learning Objectives zIdentify and explain the use of service-entrance equipment and conduit. zDescribe advantages and disadvantages of circuit breakers and fuses. zIdentify and explain the use of outlet and device boxes.

5. Student Learning Objectives zIdentify and explain the use of lampholders, switches, and controls. zIdentify and explain the use of receptacles, wall plates, and box covers.

6. Student Learning Objectives zIdentify and explain the use of miscellaneous equipment. zIdentify and explain the use of various electrical tools.

7. Terms z240-volt receptacles zBlank covers zBox hangers zCable connectors zCable ripper zCombination switch and receptacle zConnectors zCouplings zDuplex receptacles zEntrance cap or heads zEntrance elbow zExtension rings zFish tape and reel

8. Terms zFlexible metallic conduit zFlexible nonmetallic liquid tight tubing zFlush-mounted device boxes zFour-way switches (DPDT) zFused-receptacle zGround rods and clamps zGrounding screws, clips, and pigtails zHumidistats zKeyless lampholders zKnockout seals zLineman’s pliers

9. Terms zLong-nose pliers zMetallic octagon boxes zMetallic square boxes zMulti-purpose tool zNonmetallic boxes zPull-chain lampholders zRigid metallic conduit zRigid nonmetallic conduit zScrewdrivers zService entrance panel (SEP) zSingle-pole switches (SPST) zSolderless connectors zSplit-bolt connectors zStraps or staples

10. Terms zSurface-mounted device boxes (handy boxes) zTest light zThermostats zThinwall conduit (EMT) zThree-way switches (SPDT) zWall plates

11. Objective 1: How are service-entrance equipment and conduit identified and what are their uses?

12. Service Entrance Eqt. zService-entrance equipment is used in servicing electrical work in homes or buildings through the circuit breaker box or fuse box.

13. Conduit zConduit is used primarily in commercial agricultural buildings as well as in regular commercial or public buildings as opposed to typical agricultural buildings or homes.

14. Conduit zGenerally, conduit is used when protection from mechanical damage is important.

15. Entrance caps or heads zUsed to protect the exposed end of the conduit or entrance cable that brings the electrical service into the building or home.

16. Entrance caps or heads zIts primary purpose is to keep water from entering the conduit or cable sheath and short circuiting the wires. zThey are found in three common types including:

17. Flange-type Pictures by Allen Ritter

18. Conduit Type Pictures by Allen Ritter

19. Service Cable type Pictures by Allen Ritter

20. Entrance Elbow zUsed where conduit or cable enters a building. It has a removable cover to aid in installing the wires. Pictures by Allen Ritter

21. Service Entrance Panel (SEP) zUsed to control all electricity in the building. zIt should be located in a dry location and on an interior wall to avoid temperature extremes that would encourage condensation and corrosion.

22. Service Entrance Panel (SEP) zAn SEP may be either a fuse-type or circuit-breaker type. zIn either case, there will be a main fuse or main breaker to disconnect power to all circuits.

23. Service Entrance Panel (SEP) zThe SEP will also contain individual fuses or breakers for each branch circuit in the building.

24. Fuses zFuses can be found in a cartridge type or plug type.

25. Types of Fuses 1. standard plug fuse which has an internal fusible link 2. time-delay fuse which is designed to stand a temporary overload that may exist if an electric motor is starting 3. nontamperable fuse which has a different size base which requires a special adapter that is screwed into the standard fuse socket

26. Circuit Breakers zCircuit breakers operate on the principle that some metals expand more than others when heated equally. zThe breaker has two contacts that are held together by a bimetal latch.

27. Circuit Breakers zIf current flow through the breaker is greater than its rating, the bimetal strip heats and bends causing the contact points to open. zWhen the breaker has cooled sufficiently, the breaker may be reset by moving the toggle to the “off” position and then again to “on.”

28. Rigid metallic conduit zResembles galvanized water pipe, except that it is softer and easier to bend. zIt is available in the same trade sizes as water pipe from ½ inch up. z It is fastened to boxes by means of locknuts and bushings.

29. Rigid metallic conduit Pictures by Allen Ritter

30. Rigid nonmetallic conduit zSimilar to metallic except that it is made of plastic. zSpecial plastic fittings are often cemented together.

31. Thinwall conduit zSometimes referred to as EMT zIs not threaded but is coupled together with special pressure-type fittings. Pictures by Allen Ritter

32. Thinwall conduit zCouplings are used to join two pieces of thinwall conduit zConnectors are used to join the conduit to boxes.

33. Thinwall conduit zThinwall conduit is available in the same inside diameters as rigid conduit except that it is not generally made larger than 2-inch.

34. Thinwall conduit zThinwall conduit is often preferred in indoor applications while rigid conduit may be preferred in outdoor applications

35. Flexible nonmetallic liquid tight tubing zmay replace EMT in many agricultural applications. zConcentric corrugations are used to give high strength and flexibility. zIt is particularly useful in damp locations where metallic conduit would corrode

36. Flexible metallic conduit zis often used to protect conductors leading to motors where vibration prevents the use of EMT or rigid conduit.

37. Objective 2 What are the advantages of using circuit breakers and fuses?

38. Advantages of breakers / fuses zCircuit breakers and fuses offer over-current protection to individual branch circuits in agricultural buildings or homes. zEach device has several advantages or disadvantages depending on their use or application.

39. Fuses vs. Breakers zThere are no moving parts in fuses. zFuses are faster. yThe time required to open a fused circuit when a short circuit occurs is usually less than for any other protective device.

40. Fuses vs Breakers zFuses are more reliable. zA given cross section of metal will always melt at a given temperature where a circuit breaker may not trip due to corrosion or sticking.

41. Fuses vs Breakers zFuses are not affected by age or use, while circuit breakers may weaken and trip when they should not. zFuses are not affected by lack of maintenance. yCircuit breakers should be tripped periodically to keep them moving freely.

42. Fuses vs Breakers zFuses are economical because the initial cost of the equipment is less. zCircuit breakers may have a higher initial cost, but there is no cost involved in resetting the breakers as there is in replacing fuses.

43. Fuses vs Breakers zWhen a fuse blows, one may be tempted to replace it with a larger amperage fuse which would not be as safe as a circuit breaker in this case.

44. Fuses vs Breakers zCircuit breakers are more convenient to switch off when necessary and easier to switch back on after an interruption.

45. Objective 3 How do you identify outlet and device boxes and how are they used?

46. Outlet and Device boxes zOutlet and device boxes are generally used at every receptacle, switch, light, or junction point where wires are attached or spliced.

47. Outlet and Device boxes zOutlet boxes are usually octagonal or square. zDevice boxes may be flush mounted or surface mounted.

48. Nonmetallic boxes zUsed in damp or dusty agricultural buildings for all receptacles, switches, or junction boxes. zGasketed covers are necessary on nonmetallic electrical boxes to seal out dust, moisture, and corrosive gases.

49. Metallic octagon boxes zare usually made of galvanized steel and are normally 4 inches in diameter and 1 ½ inches deep, although other sizes are available. zThey are available with cable clamps, or with knockouts that may be removed for attaching cable or conduit connectors.

50. Metallic square boxes zare generally 4 inches across and 1 ½ inches deep. zThey are often used in place of octagon boxes when more wires are needed than would be permitted in an octagon box. zThey are available with or without cable clamps.

51. Extension rings zare available for both octagon and square boxes. zExtension rings provide additional room when more wires are needed than are permitted in a single box.

52. Flush-mounted device boxes zUsed in the home or in any finished building where you wish to conceal the wiring in the walls. zMost common are the beveled corner device boxes with clamps for nonmetallic cable, and the square corner boxes with or without cable clamps.

53. Flush-mounted device boxes zThe sides are removable so that two or more boxes can be “ganged” together to provide for a series of switches or receptacles at one location.

54. Surface-mounted device boxes or handy boxes zMade for fastening to an exposed surface. zThey have rounded corners and are generally not equipped with cable clamps. zThey may be used for conduit or cable wiring.

55. Objective 4 How do you identify lampholders, switches, and controls and how are they used?

56. Lampholders zLampholders are used as a light fixture in many agricultural applications. zThey are wired the same as most different kinds of lights that are used in homes.

57. Keyless lampholders zare controlled by a separate switch or switches in the line.  Common porcelain lampholders are made to fit on 4-inch octagon boxes. Pictures by Allen Ritter

58. zSwitches are used to turn the lights off and on. zThe type of switch used will depend on how many switches will control the same light(s). Pictures by Allen Ritter

59. Pull-chain lampholders zHave a built-in switch which is turned off and on at the lampholder with a string or chain.

60. Single-pole switches (SPST) zare used to break the connection in a single hot wire. zThey have only two terminal screws and are used to control lights or receptacles from one location. zThey also have the words “on” and “off” on the toggle.

61. Three-way switches (SPDT) zare used in pairs to control lights or receptacles from two different locations. zThey have three terminal screws. Pictures by Allen Ritter

62. Three-way switches (SPDT) zThey have no words written on the toggle as they may be on or off in the up or down position depending on the position of the other switch.

63. Four-way switches (DPDT) zare used in conjunction with a pair of three-way switches. zThey are useful when you want to control lights or receptacles from three or more different locations.

64. Four-way switches (DPDT) zFour-way switches have four terminal screws on them and like the three-way switch, do not have on or off written on the toggle.

65. Thermostats zare controls used to control heating and cooling systems.

66. Humidistats zare used to control humidity levels.

67. Objective 5 How do you identify receptacles, wall plates, and box covers and how are they used?

68. Receptacles zReceptacles are used to access electricity by any device that has a plug-in and cord on it. zThey come in many different types. zWall plates and box covers are used to enclose the fronts of receptacles, switches, or boxes.

69. Duplex receptacles zare double plug-in outlets, which may be installed in a variety of different types of boxes. zEach duplex receptacle has two pair of terminal screws. Pictures by Allen Ritter

70. Duplex receptacles zMost receptacles have a “pry out” connection on the “hot” side which can be removed in case you wish to control each individual receptacle separately.

71. Duplex receptacles zGrounding-type receptacles have a green-colored terminal for attaching grounding wires. zThey also have the additional third slot for three-pronged plugs.

72. 240-volt receptacles zare installed for appliances requiring 240 volts. zDifferent slot arrangements are used depending on the amperage rating of each.

73. Combination switch and receptacle zIs used when you have a convenience outlet in the same device box with a switch.

74. Combination switch and receptacle zThey may be connected so that the outlet is always “hot” and the switch controls one or more lights in the room or building. zThey may also be connected so that the switch controls the outlet.

75. Fused-receptacle zA offers protection to the appliance plugged into it. zThe appliance is protected by a fuse contained in the receptacle. Pictures by Allen Ritter

76. Wall plates zare used to cover switches, duplex receptacles, and any combination of switches and receptacles that may single or ganged together in groups. zThey are available in plastic, metal, glass and other materials.

77. Blank covers zare used on octagon, square, or handy boxes that are simply junction points. zIn other words, they are used when there is just wire and no device is mounted in a box.

78. Objective 6 How do you identify miscellaneous equipment and how is it used?

79. Miscellaneous Equipment zIn order to complete a wiring project, many other types of miscellaneous equipment are necessary.

80. Cable connectors zare used to fasten cables to boxes that do not have built-in cable clamps. zThey are connected by inserting them into a knockout opening and secured with a nut. Pictures by Allen Ritter

81. Split-bolt connectors zare often used when splicing larger size conductors such as outdoor wires to entrance wires.

82. Solderless connectors zSometimes called “wire nuts”, are used to splice smaller conductors such as those in typical wiring applications. zMost have an insulated cover, which twists onto a spliced wire. Pictures by Allen Ritter

83. Solderless connectors zIt holds the splice in place as well as insulating the splice. zDifferent sizes are available depending on the size of conductor and number of conductors being used.

84. Straps or staples zare used to fasten conduit and cable to the surfaces over which they run.

85. Box hangers zare useful in mounting outlet boxes, particularly in new work.

86. Knockout seals zare available to close unused openings where knockouts have been removed. zThey are used to keep mice, dirt, and trash away from the wires inside the box.

87. Grounding screws, clips, and pigtails zare used to connect grounding conductors to boxes.

88. Ground rods and clamps zare important in agricultural wiring. zGround rods are made of copper or copper covered steel and are driven deep into the ground to provide for grounding. zGround clamps are used to attach a ground wire to the ground rod

89. Objective 7 How do you identify various electrical tools and how are they used?

90. A variety of tools are necessary to satisfactorily complete a wiring job.

91. Test light zis used to trace circuits, test fuses and lines.

92. Multi-purpose tool zUsed for cutting wire, stripping conductors, and attaching terminals to conductors.

93. Lineman’s pliers zUsed for cutting wires and gripping locknuts. Pictures by Allen Ritter

94. Cable ripper zUsed for stripping insulation back off of cable

95. Fish tape and reel zUsed to fish wire through walls or conduit.

96. Long-nose pliers zMay be used to cut wire as well as put loops on the ends of conductors so they can be attached to terminals.

97. Screwdrivers zare used to tighten screws and locknuts on cable connectors.

98. Review z Identify and explain the use of service-entrance equipment and conduit. zDescribe advantages and disadvantages of circuit breakers and fuses. zIdentify and explain the use of outlet and device boxes.

99. Review zIdentify and explain the use of lampholders, switches, and controls. zIdentify and explain the use of receptacles, wall plates, and box covers.

100. Review zIdentify and explain the use of miscellaneous equipment. zIdentify and explain the use of various electrical tools.