Welcome : Welcome Lesson 107
Toolbox Talk : Toolbox Talk HORSEPLAY IS NO JOKE
It seemed like a sure way to get some laughs. Some of the guys greased the rungs of Bill's ladder while he was up there with a can of paint. But the punch line wasn't very funny. Bill decided to press criminal charges and is preparing a civil suit to cover the cost of his broken ankle and lost work time. Some old friendships came to an end that day.
Was this just a case of a practical joke gone wrong? Or was it more proof that practical jokes in the work place are always wrong? Chances are that in Bill's case, one person suggested the joke, and the others went along with it against their better judgment, maybe because no one wanted to make waves. There is someone at every job site with a warped sense of humor who is always thinking up ways to get a laugh at another worker's expense. But deep down inside most of us feel uneasy around this sort of person. We never know where this loose cannon is going to strike next. The best thing you can do for yourself and others is to listen to your inner voice. Let the jokester know in no uncertain terms that you're not going along with the joke. You'd be surprised at how many other people are thinking the same thing but don't have the courage to say it.
Toolbox Talk : Toolbox Talk Let's talk about some of the results of horseplay gone wrong. While some people can laugh it off when they are the butt of a joke, others may be humiliated or embarrassed. Such jokes may result in anger, hurt feelings, distrust between workers, and even a desire for revenge. When practical jokes are common at a work site, it's hard to pay attention to your job, because you're always on the lookout for the next joke. Horseplay is a safety hazard that can quickly get out of hand and lead to injury or death. If you get hurt as a result of horseplay, don't expect to be covered by workers' compensation, it's not a job related injury .If someone else gets hurt as a result of your horseplay or joke, you may be liable for damages. You will definitely be at risk of losing your job.
It's up to all of us to keep horseplay from getting out of hand. It's a matter of not going along with it. You don't have to confront a practical jokester in front of everybody. Take the person aside and talk confidentially. Point out that such acts as tripping, throwing tools, rearranging or hiding equipment, playing games with compressed air, can cause serious injury to your buddies. Horseplay is not only dangerous it's unfair and stupid.
Did I say that humor on the job is wrong? No way. Being able to laugh is what gets most of us through a day's work. Be as funny as you like, as long as it's not at someone else's expense or a safety hazard. Now, anyone have a good joke to tell?
Daily Objectives : Daily Objectives 107.1 Demonstrate knowledge of ratios, proportions, squared and square root numbers,area, and volume by applying their uses as a means of solving problems encountered by electricians.
107.2 Obtain a fundamental understanding of the principles of Ohm's Law.
Daily Objectives : Daily Objectives 107.3 Demonstrate knowledge of outlet boxes by identifying each outlet box's.
107.4 Demonstrate knowledge of symbols by identifying them as they are presented within the text and determine minimum NEC requirements for box fill and installation by reviewing NEC material.
Homework Review : Homework Review Discuss Homework from
Lesson
Daily Participation Quiz : Daily Participation Quiz Know how to apply and use Ohm's Law.
Identify the different types of boxes used in the electrical trade.
Lesson 107.1 : Lesson 107.1 Review Math Skills
and Apply to the Electrical Trade
Slide 9 : Lesson 107.2 Introduction of Ohm's Law
Ohm's Law : Ohm's Law Georg Simon Ohm developed Ohm's Law in 1827.
This is the law of relationships between Current (I), Voltage (E), Resistance (R), and Power (P).
This law is the fundamental basis of electrical study and you will use it throughout your electrical career.
Ohm's Law : Ohm's Law Ohm's Law states that 1 volt of electrical pressure will force 1 ampere of current to flow through 1 ohm of resistance.
Ohm's Law : Ohm's Law These words can be mathematically stated as formulas.
I = E / R E = I x R R = E / I P = I x E
I = P / E E = P / I R = E² / P P = I² x R
____ _____
I = vP / R E = vP x R R = P / I² P = E² / R
Ohm's Law : Ohm's Law
Daily Participation Quiz : Daily Participation Quiz C
Daily Participation Quiz : Daily Participation Quiz C
Daily Participation Quiz : Daily Participation Quiz D
Slide 17 : Lesson 107.3 Outlet Boxes
Outlet Boxes : Outlet Boxes Metal device (switch) boxes are available in various depths
Outlet Boxes : Outlet Boxes Device boxes that can be mounted to a structural member (such as a joist or stud) are commonly referred to as “scab-on” or “bracket” boxes.
Outlet Boxes : Outlet Boxes Another type of box is the octagon box.
Theses are sometimes called 4/0 (“four-oh”) boxes because they are four inches across.
Outlet Boxes : Outlet Boxes One of the most commonly used boxes is a 4 – inch square outlet box. These are frequently called “4 square” or “1900” or “Raco 232” boxes.
Outlet Boxes : Outlet Boxes Another type of box that is similar to a 4-inch square box is the 4 11/16" box.
These are sometimes called “2100” or “411” boxes.
These are 11/16" larger than a 4-square box but they are also distinguished because they have four 8-32 cover mounting holes.
Outlet Boxes : Outlet Boxes Another type of box is the masonry box.
These are often called “brick” boxes because they are frequently installed in brick walls.
Outlet Boxes : Outlet Boxes Weatherproof outlet boxes (Bell boxes) are available in round , single-gang, two-gang, and three-gang types.
The entries into boxes are threaded and these entries are typically ½ or ¾ inch.
The boxes are referred to by the number of hubs (or outlets).
Weatherproof Outlet Box : Weatherproof Outlet Box
Slide 26 : Daily Participation Quiz D
Slide 27 : Daily Participation Quiz E
Slide 28 : Daily Participation Quiz D
EWR Chapter 2 : EWR Chapter 2 Electrical Symbols and Outlets
Slide 30 : EWR Chapter 2 Identify and explain the electrical outlet symbols used in the plans of the single-family dwelling.
Discuss the types of outlets, boxes, luminaires, and switches used in the residence. Chapter 2: Objectives
EWR Chapter 2 : EWR Chapter 2 Chapter 2: Objectives Explain the methods of mounting the various electrical devices used in the residence.
Understand the preferred way to position receptacles in wall boxes.
Understand issues involved in remodel work.
EWR Chapter 2 : EWR Chapter 2 Chapter 2: Objectives Understand how to determine the maximum number of conductors permitted in a given size box.
Understand the concept of fire resistance rating of walls and ceilings.
EWR Chapter 2 : EWR Chapter 2 Symbols Electrical symbols are used on plans to show the location and type of electrical devices required.
A receptacle outlet is an outlet where one or more receptacles are to be installed.
A lighting outlet is an outlet intended for the direct connection of a lampholder.
EWR Chapter 2 : EWR Chapter 2 Use of electrical symbols and notations on a floor plan. Figure 2-1
EWR Chapter 2 : EWR Chapter 2 Symbols (continued) An outlet is defined by the NEC® as “a point on the wiring system at which current is taken to supply utilization equipment.”
A device per the NEC® is “a unit of an electrical system that carries or controls electrical energy as its principal function.”*
EWR Chapter 2 : EWR Chapter 2 Symbols (continued) An opening is a generic term that includes lighting outlets, receptacle outlets, junction boxes, and other enclosures.
EWR Chapter 2 : EWR Chapter 2 Receptacle OutletFigure 2-2
EWR Chapter 2 : EWR Chapter 2 Outlet, Device, and Junction Boxes Article 314 contains much detail about outlet boxes, pull boxes, junction boxes, and conduit bodies.
NEC® 300.11 and 314.23: Boxes must be securely mounted and fastened in place.
NEC® 300.15 states where electrical boxes must be used.
EWR Chapter 2 : EWR Chapter 2 Outlet, Device, and Junction Boxes (continued) NEC® 300.15(C) states where electrical fittings must be used.
Some boxes can be connected together or ganged.
EWR Chapter 2 : EWR Chapter 2 Surface Extensions Figure 2-17(A)
EWR Chapter 2 : EWR Chapter 2 Surface Extensions Figure 2-17(B)
EWR Chapter 2 : EWR Chapter 2 Surface Extensions Figure 2-17(C)
EWR Chapter 2 : EWR Chapter 2 Outlet, Device, and Junction Boxes (continued) There are many approved box-mounting methods and hardware.
NEC® 314.20 - boxes must be mounted:
Not more than ¼ inch (6 mm) back from the surface of noncombustible walls or ceilings.
Flush with the surface for combustible walls or ceilings.
EWR Chapter 2 : EWR Chapter 2 Remodel (Old Work) When installing a new box in a finished wall, carefully locate the installation point after considering how the electrical wires will be “fished,” or brought to the box.
Madison Hold-Its™* can be used to secure cut-in boxes.
*Hold-It™ is a brand name trademark owned by Madison Equipment Co., Cleveland, Ohio.
EWR Chapter 2 : EWR Chapter 2 Madison Hold-ItsTM Figure 2-27
Slide 46 : Remodel (Old Work) (continued) Other types of re-work boxes have specially designed wings or ears for mounting purposes. EWR Chapter 2
Slide 47 : Spread of Fire To protect lives and property, fire must be contained and not be allowed to spread.
The NEC® and other building codes must be followed.
Do not install electrical boxes back-to-back.” EWR Chapter 2
Slide 48 : Back-to-Back Boxes Figure 2-29 EWR Chapter 2
Slide 49 : Spread of Fire (continued) The thickness of wall materials must conform to Codes to be acceptably fire rated.
Special insulation around wall penetrations by cables, or pipes, prevents drafts. EWR Chapter 2
Slide 50 : Spread of Fire (continued) NEC® 314.21 requires that “there … be no gaps or open space greater than 1/8 in. (3 mm) at the edge of the box or fitting.” EWR Chapter 2
Slide 51 : Special-Purpose Outlets Special-purpose outlets are usually indicated on the plans.
Requirements may be a 240-volt circuit, a special grounding receptacle, or a dedicated circuit.
There is a Schedule of Special Purpose Outlets in the specifications for the house in the text. EWR Chapter 2
Slide 52 : Number of Conductors in a Box Table 314.16(A) gives information about the volume of metal boxes and the maximum number of conductors of the same size that can be safely installed in a given type of box.
Table 314.16(B) gives information about the volume allowance requirements for various wire sizes. EWR Chapter 2
Slide 53 : Number of Conductors in a Box (continued) Article 314 gives the rules for sizing boxes in a wide variety of applications.
Nonmetallic boxes are marked by the manufacturer with their cubic-inch capacity.
Additional wiring space is provided by plaster rings, domed covers, and extension rings. EWR Chapter 2
Slide 54 : Considerations for Determining Proper Size Boxes Refer to the NEC ® Article 314.
Internal cable clamps
Support fittings – luminaire studs or hickeys
Device or equipment – devices on a yoke
Equipment grounding conductors
Isolated equipment grounding conductor EWR Chapter 2
Slide 55 : Considerations for Determining Proper Size Boxes (continued) Conductors passing through the box
Outside conductors that terminate in the box
Conductors that do not leave the box – jumpers
Small EGC from luminaire canopy EWR Chapter 2
Slide 56 : Height of Receptacle Outlets The NEC® does not specify mounting heights or locations.
Electricians consult the plans and specifications for mounting heights.
These dimensions can be verified by the architect, electrical engineer, designer, or homeowner.
Table 2-2 shows typical mounting heights. EWR Chapter 2
Slide 57 : Typical Heights for Switches, Receptacles, and Wall Luminaire Outlets Regular 46 inches (1.15 m)
Between counter 44 in.–46 in. and kitchen cabinets (1 m–1.15 m) SWITCHES EWR Chapter 2
Slide 58 : Typical Heights for Switches, Receptacles, and Wall Luminaire Outlets (continued) RECEPTACLE OUTLETS Regular 12 in. (300 mm)
Between counter and
kitchen cabinets 44 in.–46 in. (1 m–1.15 m)
Garages 46 in. (1.15 m) Min 18 in. (450 mm)
Unfinished basements 46 in. (1.15 m)
Finished basements 12 in. (300 mm)
Outdoors 18 in. (450 mm) EWR Chapter 2
Slide 59 : Typical Heights for Switches, Receptacles, and Wall Luminaire Outlets (continued) Outside entrances 72 in. (1.8 m)
Inside wall brackets 5 ft (1.5 m) WALL LUMINAIRE OUTLETS EWR Chapter 2
Homework : Homework Read over material contained within lesson
Complete Objective 107.1– 107.3 worksheets.
Look ahead to lesson 108