Eim Ncii Lmg9 p147-217

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QUARTER IV

QUARTER IV Time Allotmen Time Allotment: 40 Hourst: 40 Hours LESSON: INSTALLING ELECTRICAL LIGHTING SYSTEMS, AUXILIARY LESSON: INSTALLING ELECTRICAL LIGHTING SYSTEMS, AUXILIARY OUTLETS AND LIGHTING FIXTURES

OUTLETS AND LIGHTING FIXTURES I.INTRODUCTION:

I.INTRODUCTION: This

This module module contains contains the the “know” “know” and and “do” “do” practices practices inin Installation ofInstallation of Electrical Lighting System on Auxiliary Outlets and Lighting Fixtures

Electrical Lighting System on Auxiliary Outlets and Lighting Fixtures ..

It covers the knowledge, skills and

It covers the knowledge, skills and attitudes required in installing the lightingattitudes required in installing the lighting fixtures. Specifically, this module covers installation of knob and tube, PVC fixtures. Specifically, this module covers installation of knob and tube, PVC raceway/m

raceway/molding, rigid non-metallic olding, rigid non-metallic conduit, and conduit, and flexible non-metallic conduit.flexible non-metallic conduit. This

This module module consists consists ofof Learning Outcomes (LO’s) that contain learningLearning Outcomes (LO’s) that contain learning activities for both knowledge and skills supported with information sheets, activity activities for both knowledge and skills supported with information sheets, activity sheets, and self-check. Before attempting to perform the manual exercises, see to it sheets, and self-check. Before attempting to perform the manual exercises, see to it that you have already read and understood the information/activity sheet and that you have already read and understood the information/activity sheet and answered correctly the self-check provided in

answered correctly the self-check provided in the Learning Activities.the Learning Activities.

II. LO2- INSTALLING ELECTRICAL LIGHTING SYSTEMS, AUXILIARY OUTLETS II. LO2- INSTALLING ELECTRICAL LIGHTING SYSTEMS, AUXILIARY OUTLETS AND LIGHTING FIXTURES

AND LIGHTING FIXTURES 1.

1. Select appropriate electrical tools, equipment, and materials for specificSelect appropriate electrical tools, equipment, and materials for specific tasks

tasks 2.

2. Apply suitable wiring method for the jobApply suitable wiring method for the job 3.

3. Install electrical wiring systems using different types oInstall electrical wiring systems using different types o f wiring methods:f wiring methods: 

 Circuit with one bulb controlled by surface or flush type single poleCircuit with one bulb controlled by surface or flush type single pole switch

switch 

 Circuit using 3-way switches in two locationsCircuit using 3-way switches in two locations 

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III. PRE/DIAGNOSTIC ASSESMENT:

TEST I: Directions:

TEST I: Directions: Choose the correct answer. Write the letter of your answer Choose the correct answer. Write the letter of your answer on a separate sheet of paper.

on a separate sheet of paper. ____1. What t

____1. What types of wypes of wiring method iring method is commonly is commonly found in old homfound in old homes?es? a.

a. open open wiring wiring b. b. open open knob knob and and tube tube wiringwiring c.

c. concealed concealed wiring wiring d. d. none none of of thesethese ____2. In ins

____2. In installing an talling an electrical wirielectrical wiring systeng system with thm with the exposed knob e exposed knob and tubeand tube wiring method, what is

wiring method, what is the minimum distance between conductors thatthe minimum distance between conductors that should be maintained ?

should be maintained ? a.

a. 4 4 centimeters centimeters b. b. 6 6 centimeters centimeters c. c. 12 12 centimeters centimeters d. d. 30 30 centimeterscentimeters ____3. The exposed knob and tube wiring method, requires that the knobs must be ____3. The exposed knob and tube wiring method, requires that the knobs must be

_____ centime

_____ centimeters apartters apart

?

a.

a. 4 4 centimeters centimeters b. b. 6 6 centimeters centimeters c. c. 12 12 centimeters centimeters d. d. 30 30 centimeterscentimeters ____4. Whenever wires

____4. Whenever wires cross each cross each other, what other, what electrical materials are electrical materials are necessary tonecessary to provide protection from injury?

provide protection from injury? a.

a. mica mica tube tube b. b. porcelain porcelain tube tube c. c. circular circular loom loom d. d. all all of of thesethese ____5. What

____5. What type of switctype of switching contrhing controls a bulb in twols a bulb in two different locao different locations?tions? a.

a. Three-way Three-way switch switch b. b. Switchgear Switchgear c. c. Four-way Four-way switch switch d. d. single single pole pole switchswitch ____6.

____6. This type of This type of conduit is manconduit is manufactured to ufactured to be resistant be resistant to impact ato impact andnd crushing moisture, chemical atmospher

crushing moisture, chemical atmosphere, flame e, flame retardant or not retardant or not easilyeasily burned and get out shape by the heat.

burned and get out shape by the heat. a.

a. PVC PVC b. b. Rigid Rigid Nonmetallic Nonmetallic Conduit Conduit c. c. Surface Surface Raceway Raceway d. d. Wire Wire waysways

____

____ 77. . WWhat is the minimum burial depth of PVC buried underground in a 50 mmhat is the minimum burial depth of PVC buried underground in a 50 mm thick concrete trench?

thick concrete trench? a.

a. 15 15 millimeters millimeters b. b. 30 30 millimeters millimeters c. c. 50 50 millimeters millimeters d. d. 300 300 millimetersmillimeters

____

____ 8.8. WWhat is the minimum burial depth of PVC directly buried under drivewayshat is the minimum burial depth of PVC directly buried under driveways and parking lots of single and two family dwelling units ?

and parking lots of single and two family dwelling units ? a.

a. 460 460 mm mm b. b. 400 400 mm mm c. c. 350 350 mm mm d. d. 300 300 mmmm

____

____ 9.9. WWhat is the minimum burial depth of PVC directly buried under airporthat is the minimum burial depth of PVC directly buried under airport runways, including adjacent areas where trespassing is prohibited ?

runways, including adjacent areas where trespassing is prohibited ? a.

____

____ 10. What is the process wherein rough edges or burrs at the cut ends of 10. What is the process wherein rough edges or burrs at the cut ends of non- non-metallic conduit shall be trimmed

metallic conduit shall be trimmed inside and outside?inside and outside? a.

(3)

III. PRE/DIAGNOSTIC ASSESMENT:

TEST I: Directions:

TEST I: Directions: Choose the correct answer. Write the letter of your answer Choose the correct answer. Write the letter of your answer on a separate sheet of paper.

on a separate sheet of paper. ____1. What t

____1. What types of wypes of wiring method iring method is commonly is commonly found in old homfound in old homes?es? a.

a. open open wiring wiring b. b. open open knob knob and and tube tube wiringwiring c.

c. concealed concealed wiring wiring d. d. none none of of thesethese ____2. In ins

____2. In installing an talling an electrical wirielectrical wiring systeng system with thm with the exposed knob e exposed knob and tubeand tube wiring method, what is

wiring method, what is the minimum distance between conductors thatthe minimum distance between conductors that should be maintained ?

should be maintained ? a.

a. 4 4 centimeters centimeters b. b. 6 6 centimeters centimeters c. c. 12 12 centimeters centimeters d. d. 30 30 centimeterscentimeters ____3. The exposed knob and tube wiring method, requires that the knobs must be ____3. The exposed knob and tube wiring method, requires that the knobs must be

_____ centime

_____ centimeters apartters apart

?

a.

a. 4 4 centimeters centimeters b. b. 6 6 centimeters centimeters c. c. 12 12 centimeters centimeters d. d. 30 30 centimeterscentimeters ____4. Whenever wires

____4. Whenever wires cross each cross each other, what other, what electrical materials are electrical materials are necessary tonecessary to provide protection from injury?

provide protection from injury? a.

a. mica mica tube tube b. b. porcelain porcelain tube tube c. c. circular circular loom loom d. d. all all of of thesethese ____5. What

____5. What type of switctype of switching contrhing controls a bulb in twols a bulb in two different locao different locations?tions? a.

a. Three-way Three-way switch switch b. b. Switchgear Switchgear c. c. Four-way Four-way switch switch d. d. single single pole pole switchswitch ____6.

____6. This type of This type of conduit is manconduit is manufactured to ufactured to be resistant be resistant to impact ato impact andnd crushing moisture, chemical atmospher

crushing moisture, chemical atmosphere, flame e, flame retardant or not retardant or not easilyeasily burned and get out shape by the heat.

burned and get out shape by the heat. a.

a. PVC PVC b. b. Rigid Rigid Nonmetallic Nonmetallic Conduit Conduit c. c. Surface Surface Raceway Raceway d. d. Wire Wire waysways

____

____ 77. . WWhat is the minimum burial depth of PVC buried underground in a 50 mmhat is the minimum burial depth of PVC buried underground in a 50 mm thick concrete trench?

thick concrete trench? a.

a. 15 15 millimeters millimeters b. b. 30 30 millimeters millimeters c. c. 50 50 millimeters millimeters d. d. 300 300 millimetersmillimeters

____

____ 8.8. WWhat is the minimum burial depth of PVC directly buried under drivewayshat is the minimum burial depth of PVC directly buried under driveways and parking lots of single and two family dwelling units ?

and parking lots of single and two family dwelling units ? a.

____

____ 9.9. WWhat is the minimum burial depth of PVC directly buried under airporthat is the minimum burial depth of PVC directly buried under airport runways, including adjacent areas where trespassing is prohibited ?

runways, including adjacent areas where trespassing is prohibited ? a.

____

____ 10. What is the process wherein rough edges or burrs at the cut ends of 10. What is the process wherein rough edges or burrs at the cut ends of non- non-metallic conduit shall be trimmed

metallic conduit shall be trimmed inside and outside?inside and outside? a.

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INFORMATION SHEET 2.1

PRINCIPLES OF KNOB AND TUBE PRINCIPLES OF KNOB AND TUBE

The

The open

open or

or exposed

exposed wiring

wiring method

method is

is sometimes

sometimes referred

referred to

to as

as the

the

Open Wiring on Insulators (PEC section 212). It uses cleats, knobs (split or

solid), porcelain tubes and mica tubing for the support and protection of

insulated conductors run in or on buildings. It may be used for exposed

work, either outside or inside building in dry or wet locations. It shall not be

used however, in the following:

1. 1. Commercial Garages

Commercial Garages

2. 2. Theaters

Theaters

3. 3. Motion Picture Studious

Motion Picture Studious

4. 4. Hoist ways

Hoist ways

5. 5. Hazardous Location

Hazardous Location

In the open or exposed wiring method, the wires are visible and are

supported by the knobs. These knobs may be the split or solid type. This is

shown in figure 1.

Figure 1

Figure 1:: The Split and Solid knobs

The Split and Solid knobs

Split knobs

Split knobs are used to support wires smaller than No. 8.

are used to support wires smaller than No. 8. Solid knobs

Solid knobs

are used to support or anchor wires as big as No. 8 or bigger. Screws or

nails may be used to fasten the knobs. When a nail is used, a leather

washer should be placed between the nail head and the insulator to form

cushion and protect the insulator from breaking (See figure 2).

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Figure 2: The Solid Knob with Leather washer for Protection

Figure 3: Shows the correct and wrong way of tying wires to the groove of a

solid knob with the wires

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In installing an electrical wiring system with the exposed knob and tube

wiring method, the distance between conductors should be maintained at a

minimum distance of 6 cm. (2 ½ inches) apart. The knobs should also

spaced 30 cm (1 feet) apart. Figure 4 illustrates this provision of PEC.

Figure 4: Spacing of Split Knobs and Conductors

Whenever wires pass through studs, rafters, floor joists or any wooden

part of a building, the wires are inserted in porcelain tubes or flexible mica

tubing. Porcelain tubes and mica tubing are also provided whenever wires

cross each other. It gives the wire extra protection from injury.

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Figure 5: Application of Porcelain Tubes and Mica Tubing

Some advantages of the Knob and Tube wiring:

1. It is used in temporary installation, such as construction jobs.

2. It has economical when properly installed.

3. It has a lower operating temperature because of ventilating hence, the

higher current carrying capacity of the wire.

Safety reminders when installing knob and tube wiring

1. Apply enough pressure on the gimlet when driving it to the word

board. Never hammer it.

2. Have the auger brace oiled regularly especially the ratchet type.

3. Have your electrician’s knife sharpened enough in order not to nick

the wire.

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5. Be sure that the conductors in contact with the wiring surface are

enclosed in mica tubing.

6. Be sure your teacher has checked your work before testing.

7. Be sure the safety switch is off before making any connection. Apply

tape on all joints/splices.

8. Do not drive the split-knobs completely before the conductors or wires

are run/inserted along the grooves of the knobs.

9. Be sure to test the insulation for short and ground circuit before

putting on the power.

Wiring installation using plastic/porcelain knobs and tubes

Install two bulb controlled individually by two single pole single throw

(SPST) switch in two locations

I

–

Materials Required

Qty

Unit

Description

2 pcs single pole, tumbler switch, surface type

2 pcs porcelain/plastic receptacle, surface type

2 pcs incandescent bulb, 220v, 25w

10 mts solid wire # 14 t.w.

17 pcs porcelain/plastic split knobs with screws

3 ft

mica tubing or loom

1 roll electric tape

1 pc

safety switch/cut out

2 pcs fuse, 10-a, cartridge type

1 pc

4’ x 4’ x3/4” wiring board

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II. Pictorial Wiring Diagram

III. Procedure:

1. Install porcelain/plastic receptacle and porcelain cut out/safety

switch to desired location.

2. Fasten split knobs to proper location and distances. Do not tighten

screws. Provide clearance for insertion of wires.

3. Provide mica tubing in every connection of the wires. Follow the

figure/drawing as shown.

4. Connect wires from receptacles to safety switch and switch them

from switch to safety switch. Tighten screw of knobs. Apply tape on

the joints.

5. Fasten switches with base under it.

6. Mount the bulbs and fuses on their respective locations.

7. Connect power and test the installation.

8. Install porcelain/plastic receptacle and porcelain cut out/safety

switch to desired location.

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9. Fasten split knobs to proper location and distances. Do not tighten

screws. Provide clearance for insertion of wires.

10. Provide mica tubing in every connection of the wires. Follow the

figure/drawing as shown.

11. Connect wires from receptacles to safety switch and switch

them from switch to safety switch. Tighten screw of knobs. Apply

tape on the joints.

12. Fasten switches with base under it.

13. Mount the bulbs and fuses on their respective locations.

14. Connect power and test the installation.

ACTIVITY SHEET 2.1

INSTALLING ELECTRICAL WIRING USING KNOB AND TUBE METHOD

Directions: Install one bulb, controlled from two locations by two 3-way

switch using plastic/porcelain knob and tube.

I

–

Materials Required

Qty

Unit

Description

2 pcs three-way switch, surface type

1 pc

porcelain/plastic receptacle, surface type

1 pc

incandescent bulb, 220v, 25w

12 mts solid wire # 14 t.w.

20 pcs porcelain/plastic split knobs with screws

3 ft

mica tubing or loom

1 roll electric tape

1 pc

safety switch/cut out

1 pc

4’ x 4’ x ¾” wiring board

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II. Pictorial Wiring Diagram

One bulb, controlled from two locations by two 3-way switch using

plastic/porcelain knob and tube

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III

–

Procedure:

1. Install porcelain/plastic receptacle and porcelain cut out/safety

switch to desired locations.

2. Fasten split knobs to proper location and distances. Do not tighten

screw. Provide clearance for insertion of wires.

3. Provide mica tubing in every connection of the wires. Follow the

figure/drawing as shown.

4. Connect wires from receptacle to safety switch and switch them

from switch to safety switch. Tighten screw of knobs. Apply tape on

the joints.

5. Fasten switches with base under it.

6. Mount the bulb and fuses on their respective locations.

7. Connect power and test the installation.

Assessment Criteria Dimensions VS 5 S 3 NI 1 1. Functionality: Bulb 2. Quality: Workmanship, Appearance 3. Accuracy: Dimension, Accurate bending 4. Method: Observance of the safety measures.

5. Speed: Submission on time +1, before the expected time +2, after the expected time_–2.

Rating Scale:

VS – Very Satisfactory = 25 – 18 S – Satisfactory = 17 – 10

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INFORMATION SHEET 2.2

FLEXIBLE NONMETALLIC CONDUIT

Flexible Nonmetallic Conduit is used as mechanical protection for electric conductors. It has a smooth interior and a wall of non-conducting fibrous material. This is the commonly used electrical wiring conduit now a days due to its economic

value.

Flexible nonmetallic conduit

(This portion of information sheet is lifted from Philippine Electrical Code, 2000, Part I.)

Definition:

Liquid tight flexible nonmetallic conduit is a listed raceway of circular cross section of various types as follows:

1. A smooth seamless inner core and cover bonded together and having one or more reinforcement layers between the core and cover designated as Type LFNC-A.

2. A smooth inner surface with integral reinforcement within the conduit wall, designated as Type LFNC-B.

3. A corrugated internal and external surface without integral reinforcement within the conduit wall, designated as Type LFNC-C.

This conduit is flame resistant and, with fittings, is approved for the installation of electrical conductors.

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Uses.

(a) Permitted. Listed liquid tight flexible nonmetallic conduit shall be permitted to be used in exposed or concealed locations for the following purposes. FPN: Extreme cold may cause some types of nonmetallic conduits to become brittle and therefore more susceptible to damage from physical contact.

(1) Where flexibility is required for installation, operation, or maintenance.

(2) Where protection of the contained conductors is required from vapors, liquids, or solids.

(3) For outdoor locations where listed and marked as suitable for the purpose. FFN: For marking requirements, see Section 110.1.21

(4) For direct burial where listed and marked for the purpose.

(5) Liquid tight flexible nonmetallic conduit as defined in Section 3.51.2.1(2) shall be permitted to be installed in lengths longer than 1 800 mm where secured in accordance with Section 3.51.2.6.

(6) As a listed manufactured prewired assembly, 15, mm (20mm) through 25 mm (32 mm) conduit, as defined in Section 3.51 .2.1(2).

(b) Not Permitted. Liquid tight flexible nonmetallic conduit shall not be used in the following:

(1) `Where subject to physical damage

(2) Where any combination of ambient and conductor temperature is in excess of that for which the liquid tight flexible nonmetallic conduit is approved

(3) In lengths longer than 1 800 mm, except as permitted by Section 3.51 .2.2(a)(5) or where a longer length is approved as essential for a required degree of flexibility.

(4) Where voltage of the contained conductors is in excess of 600 volts, nominal

Exception. As permitted in Section 6.0.2.3(a) for electric signs over 600 volts.

Sizes:

The electrical trade sizes of liquid tight flexible nonmetallic conduit shall be in accordance with (a) or (b):

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(b) 10 mm (15 mm) as permitted below

(1) For enclosing the leads of motors as permitted in Section 4.30.13.5(b) (2) In lengths not exceeding 1 800 mm as part of a listed assembly for tap

connections to lighting fixtures as required in Section 4.10.13.4(c), or for utilization equipment

(3) for electric sign conductors in accordance with Section 6.0 .2 .3 (a) Number of Conductors: The number of conductors permitted in a single

conduit shall be in accordance with the percentage fill specified.

Fittings: Liquid tight flexible non - metallic conduit shall be used only with listed terminal fittings. Angle connectors shall not be used for

concealed raceway installations.

Securing and Supporting: Liquid tight flexible nonmetallic conduit, as defined in Section 3.51.2.1(2), shall be securely fastened and supported in accordance with one of the following;

(a) The conduit shall be securely fastened at intervals not exceeding 900 mm and within 300 mm on each side of every outlet box, junction box, cabinet, or fitting.

(b) Securing and supporting of the conduit shall not be required where it is fished, installed in lengths not exceeding 900 mm at terminals where flexibility is required, or where installed in lengths not exceeding 1 800 mm from a fixture terminal connection for tap conductors to lighting fixtures as permitted in Section 4.10.13.4(c).

(c) Horizontal runs of liquid tight flexible nonmetallic conduit supported by openings through framing members at intervals not exceeding 900 mm and securely fastened within 300 mm of termination points shall be permitted.

Flexible Nonmetallic Conduit Fittings

Coupling

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Adapter

Liquid tight angle connector Liquid tight straight connector

FLEXIBLE NONMETALLIC CONDUIT

Install conduit and electrical wiring from indoor unit to outdoor unit using flexible nonmetallic tubing .

Tools, Materials and Equipment Needed Equipment/Instruments: o Electric drill o Multi-tester -1 unit 1 unit Materials: o Pencil or Chalk - 1 pc

o Installation plan or working drawing - 1 pc o Flat head screw, ¾ in X 10 - 15 pcs

o *Fisher, # 6 (tox) - 15 pcs

o Flexible nonmetallic tubing - 5 mts

o Mica tube, ¼ in. dia. - 1 mts

o Stranded wire, 2.0 mm2 TW - 10mts o Safety switch, 30 A o Guide wire -2 pcs 3 m Tools:

o Pull and push rule or any measuring

device suited for the activity

- 1 pc

o Steel meter stick/Straight edge - 1 pc

Personal Protective Equipment:

o Safety glass - 1 pc

o Gloves - 1 pair

o Goggles - 1 pc

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Note: In installing electrical circuit, you may use any type of approved wiring method for the purpose. It has been a practice in this field to use flexible nonmetallic tubing

because flexibility is required for installation, operation, and maintenance. You may use rigid nonmetallic conduit (PVC) as discussed in the previous instruction sheets. Procedure

1. Wear appropriate PPE

2. Measure the required length of flexible nonmetallic conduit from the outdoor unit to the indoor unit. You may use any measuring device suited for the job or you may use the actual material by practically tracing its path as shown in the picture.

3. Cut the flexible nonmetallic tubing.

4. Insert the wires first before laying out the tubing permanently.

5. Use guide wires to facilitate easy pulling of conductors. Use galvanized iron wire, gauge 14 AWG. Insert it at one end of the tubing until it reaches the other end of the tubing.

6. Prepare the required length of the conductor. It may be as long as the length of the tubing plus an ample allowance at both ends for splicing. Then mark off the conductors at both ends to distinguish them from

each other.

Note: Allowance must be at least 150 mm(6 in) long at both ends measured from the ends of the tubing.

You may use electrical tape or masking tape in marking off the conductor.

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7. Tie the conductors securely to the guide wires.

8. Pull the guide wires at the other end of the tubing. The tubing should be laid straight forward for easy pulling o f conductors.

9. Seek assistance from other person. The conductors should be pushed from the other end while being pulled from the other end.

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11.

11.Lay the electrical tubing on the path where the refrigeration systemLay the electrical tubing on the path where the refrigeration system tubing is installed.

tubing is installed.

12.

12.Secure the flexible nonmetallic tubing wrapping it with cable tie.Secure the flexible nonmetallic tubing wrapping it with cable tie.

13.

13.Insert the connector.Insert the connector.

14.

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15.

15.Put the lock nut and tighten it.Put the lock nut and tighten it.

16.

16.Prepare the conductor for termination. Strip off at least 5 mm ofPrepare the conductor for termination. Strip off at least 5 mm of insulation

insulation..

17.

17. Terminate the Terminate the conductorconductors. s. It It is indicated is indicated in the in the manufacturmanufacturer’s manualer’s manual how to terminate the conductors.

how to terminate the conductors.

18.

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19.

19.You have just finished the electrical circuit from indoor to outdoor unit.You have just finished the electrical circuit from indoor to outdoor unit. Now, you are ready for the installation of the main power supply. The Now, you are ready for the installation of the main power supply. The main supply line is usually pre-wired by the manufacturer, all you have main supply line is usually pre-wired by the manufacturer, all you have to do is

to do is to terminate it from the circuit protection.to terminate it from the circuit protection.

20.

20. Terminate t Terminate to the circuo the circuit protection.it protection.

21.

21. Test the Test the circuit for circuit for ground short or ground short or open wiring. If open wiring. If fault is fault is found, rectifyfound, rectify it.

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22. Turn on the circuit and test run the unit.

23.Observe good housekeeping.

SELF-CHECK 2.1

Flexible Nonmetallic Conduit Fittings

Directions: Label the different types of Flexible Nonmetallic Conduit Fittings. Write your answer on a separate answer sheet.

1.

2.

3.

5.

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ACTIVITY SHEET 2.2

INSTALLING SIMPLE ELECTRICAL CIRCUIT

Directions: Your task is to install simple electrical circuit; a lamp

controlled by a single pole switch.

Tools, Materials and Equipment Needed:

Materials and Supplies Needed

Quantity Description

1 pc Pencil or chalk

1 pc Installation plan/working drawing 1pc Incandescent lamp 25watts

1 pc Lamp Holder 4” diameter 1 pc SPST switches (flush type) 1 pc 1 gang switch plate

2 pcs Junction boxes metal/plastic 1 pc Utility boxes metal/plastic

1 meter Flexible nonmetallic tubing ½”diameter 2 pcs Flexible clamps

3 meters Solid/stranded wire 1.6mm 6 pcs Flat head screws 3.4”

1 roll Electrical tape 1 set Line cord

1 pc Wiring board 1’ x 2’ x ½” Tools, equipment and Instrument Needed Combination, long nose, and side cutting pliers Flat and Philips screw drivers

Hammer Wire Stripper

Pull push rule/meter stick

Personal Protective Equipment (PPE) Safety glasses

Gloves

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Working Schematic Diagram:

Procedure:

1. Analyze the schematic diagram of a lamp controlled by a single pole

switch.

2. Outline dimensions. (Refer to the measurements specified in the

schematic diagram).

3. Using two screws per box, mount the utility and junction boxes to its

proper position.

4. Attach flexible connectors and insert the flexible tubing from the

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5. Insert solid wires (TW 1.6mm./#14awg) through the flexible tubing

from the center junction box to the:

o

utility box for the switch

o

junction box for lamp holder

and then, cut the wires with an allowance of approximately 160mm/6

inches long.

6. Remove the insulator of wires inside the:

o

utility box for about 10mm. then insert each to switch

terminals

o

junction box for about 5mm. then insert each to lamp holder

terminals

o

center junction box for about 40mm. (one coming from the

switch and the other from the lamp holder) then, splice using

rat tail joint

o

center junction box for about 10mm. (one coming from the

switch and the other from the lamp holder) then, splice each

with the flat cord going to the source.

7. Attach the switch and lamp holder to its boxes using screws.

8. Insulate all splices with electrical tape.

9. Cover the junction box and insert the lamp in the holder.

10. Using a multi-tester test the circuit for possible trouble.

11. To test the functionality of the circuit, insert the male plug to a

convenience outlet.

Sample Performance Assessment Rubrics

CRITERIA 5 POINTS 3 POINTS I POINT

FUNCTIONALITY Lamp lights Lamp lights but flickers

Lamp does not light WORKMANSHIP a. Wire Terminations All wire terminations are perfectly done.

One of the wire terminations is imperfectly done.

Two or more wire terminations are imperfectly done. b. Dimension, Mounting and Presentation - Dimensions are perfect - All boxes are

properly mounted and secured - Finished output is clean - There is an error in either dimensions or mounting of boxes - Finished output is quite messy - There are errors in both dimensions & mounting of boxes - Finished output is messy

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and neat PROCESS - The procedure was followed from start to finish / correct usage of tools/safety work habits. - The procedure was partly followed/ correct usage of tools/safety work habits - Did not follow the procedure/ correct usage of tools/safety work habits TIME MANAGEMENT

Work was done ahead of time.

Work was done just in time.

Unable to finish the work.

Score Sheet:

Criteria Group 1 Group 2 Group 3 Group 4

Functionality Workmanship a. Wire Termination b. Dimension, Mounting and Presentation Process Time Management TO T A L POINTS RATING SCALE:

Points earned Descriptive Numerical

21-25 Excellent 99

16-20 Very Good 95

11-15 Good 90

6-10 Fair 85

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ACTIVITY SHEET 2.3

BOARD WIRING INSTALLATION USING 3-WAY AND 4-WAY SWITCHES

Directions: Your task is to install wiring of 4 bulbs assigned as bulb A, B, C

and D. Bulb A is controlled in 3 locations by one 4-way switch (S

4

w) and two

3-way (S

3

w) switches. Bulbs B, C and D connected in parallel will be

controlled each by a single pole switch and a duplex convenience outlet. The

size of wiring board is 4’ x 4’ x

3

_{/4”ply wood.}

Tools, Materials and Equipment Needed:

1 pc Installation plan/working drawing 1 set Circuit breaker (for 4 branch ckt.) 4 pcs Incandescent lamp 25watts

4 pcs Lamp Holder 4” diameter

2 pcs Convenience Outlet (lush type) 3 pcs SPST switches (flush type)

1 pc 4-way switch

2 pcs 3-way switches 1 pc 1 gang switch plate 1 pc 3 gang switch plate 2 pcs 2 gang Switch plate

2 pcs Square boxes metal/plastic 4 pcs Junction boxes metal/plastic 4 pcs Utility boxes metal/plastic

8 meters Flexible nonmetallic tubing ½”diameter 20 pcs Flexible clamps

20 meters Solid/stranded wire 1.6mm 4 meters Solid/stranded wire 2.0mm 20 pcs Flat head screws 3.4”

1 roll Electrical tape

Tools, equipment and Instrument Needed Electric drill

Combination, long nose, and side cutting pliers Flat and Philips screw drivers

Gloves

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Bulb A

Bulb B

Bulb C

Bulb D

Pictorial Diagram

Note: The teacher will provide the schematic diagram.

Procedure:

1. Analyze the pictorial diagram.

2. Outline dimensions. (Refer to the measurements given by your teacher.) 3. Mount the circuit breaker, utility and junction boxes to its proper position,

using two screws per box.

4. Measure and cut the required length of flexible nonmetallic conduit.

5. Prepare the required length of the conductor. It may be as long as the length of the tubing plus an ample allowance at both ends for splicing.

Note: Allowance must be at least 150 mm(6 in) long at both ends measured from the ends of the tubing.

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7. Attach the flexible tubing with conductors permanently using flexible clamps.

8. Insert the connectors. Then, put the lock nuts and tighten.

9. Prepare the conductor for termination. Strip off at least 5 mm of insulation. 10. Make all necessary connections as required in the wiring diagram.

11. Be sure that the connections are tightened correctly.

12. Test the circuit for ground short or open wiring. If fault is found, rectify it 13. Turn on the circuit and test run the unit.

14. Observe good housekeeping.

Sample Performance Assessment Rubrics

CRITERIA 5 POINTS 3 POINTS I POINT

FUNCTIONALITY Lamp lights Lamp lights but flickers

Lamp does not light WORKMANSHIP Wire Terminations All wire terminations are perfectly done.

One of the wire terminations is imperfectly done.

Two or more wire terminations are imperfectly done. Dimension, Mounting and Presentation - Dimensions are perfect - All boxes are

properly mounted and secured - Finished output is clean and neat - There is an error in either dimensions or mounting of boxes - Finished output is quite messy - There are errors in both dimensions & mounting of boxes - Finished output is messy PROCESS - The procedure was followed from start to finish / correct usage of tools/safety work habits. - The procedure was partly followed/ correct usage of tools/safety work habits - Did not follow the procedure/ correct usage of tools/safety work habits TIME MANAGEMENT

Work was done ahead of time.

Work was done just in time.

Unable to finish the work.

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Score Sheet:

Criteria Group 1 Group 2 Group 3 Group 4

Functionality Workmanship Wire Termination Dimension, Mounting and Presentation Process Time Management TO T A L POINTS RATING SCALE:

Points earned Descriptive Numerical

21-25 Excellent 99

16-20 Very Good 95

11-15 Good 90

6-10 Fair 85

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176

INFORMATION SHEET 2.3

RIGID NONMETALLIC CONDUIT (RNC)

Rigid Nonmetallic Conduit (RNC) is non-metallic unthreaded smooth-walled tubing. They are manufactured to be resistant to moisture and chemical atmosphere, flame retardant. They are resistant to impact and crushing and, they do not easily get out shape because of heat. These conduits are classified according to the materials they are made of. The most common ones are asbestos cement conduit, polyvinyl chloride, conduit, and high density polyethylene conduit.

Poly Vinyl Chloride (PVC) pipes

The Philippine Electrical Code provides that rigid nonmetallic conduit may be used under the following conditions:

1. Concealed in floors, walls and ceilings 2. Direct earth burial or underground

 300 mm in trench below 50mm thick concrete or equivalent

 600 mm under streets, highways, roads, alleys, driveway and

parking lots

 460 mm under driveways and parking lots of single and two family

dwelling units

 460 mm under airport runways, including adjacent areas where trespassing is prohibited

3. In locations subject to severe corrosive influences and where subject chemicals for which the materials are specifically approved

4. Cinder fill

5. In wet locations, provided water is prevented from entering the conduit

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The Philippine Electrical Code prohibits the use of rigid non-metallic conduit under the following conditions:

1. Hazardous (Classified) locations 2. Support of fixtures

3. Where subject to physical damage unless identified for such use.

4. Where subject to ambient temperatures in excess of 50o_{C unless}

listed otherwise

5. Insulation Temperature Limitations. For conductors whose insulation temperature limitations would exceed those for which the conduit is listed.

6. Theaters and Similar Locations.

INSTALLATION OF NON-METALLIC CONDUIT PEC REQUIREMENTS

1. TRIMMING - edges or burrs at the cut ends of nonmetallic conduit shall be trimmed at the insides and outside.

2. JOINTS - between lengths of conduit and between conduit couplings, fittings and boxes shall be made with approved coupling and adapter. For water proofing, PVC cement should be spread around the surfaces to be .joined together.

3. SECURING and SUPPORTS - non-metallic conduit shall be rigidly supported as indicated below

Table 3.47.1.8 Support of Rigid Nonmetallic Conduit (Based on Philippine Electrical Code, 2000, Part I)

Conduit Size [mm (mm)]* Maximum Spacing Between Supports (mm) 15 (20) – 25 (32) 32 (40) – 50 (63) 65 (75) – 80 (90) 90 (100) – 125 (135) 150 (160) 900 1500 1800 2100 2400

*size indicted inside the parenthesis is the outside diameter. PVC conduits are specified to outside diameter

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4. EXPANSION FITTINGS – Expansion fitting for rigid nonmetallic conduit shall be provided to compensate for thermal expansion and contraction.

5. MINIMUM SIZE_– Rigid nonmetallic conduit smaller than 15 mm (20 mm) electrical trade size shall not be used.

6. MAXIMUM - Rigid nonmetallic conduit larger than 150 mm (160 mm) electrical trade size shall not be used.

7. BUSHING – Where conduit enters a box, fitting or other enclosure, a bushing or adapter shall be provided to protect wires from abrasion unless the box, fitting, or enclosure design provides equivalent protection.

8. BENDS-HOW MADE _– Bends of rigid nonmetallic conduit shall be made in a way that the conduit will not be damaged and that the internal diameter of the conduit will not be effectively reduced.

Table 3.46.2.6 Radius of Conduit Bends (Based on Philippine Electrical Code, 2000, Part I)

Size of Conduit (mm)

Conductors Without Lead Sheath 15 20 25 32 40 50 65 80 90 100 125 150 100 125 150 200 250 300 375 450 525 600 750 900

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TYPES OF PVC CODUIT FITTINGS

PVC Coupling PVC elbow

Adapter PVC Conduit Pipe

PVC 2G box LL Access Fitting

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Different types of Surface Raceway

Identifying Different Types of Bend

The PVC or (polyvinyl chloride) rigid conduit is one of the most commonly used conduits in electrical wiring installation today. Its preparation for installation is much easier than the metallic rigid conduit. In preparing a non-metallic rigid conduit for installation, an electrician needs to do cutting, heating and bending. Like in metallic rigid conduit offset bends, 90o_{angle bends and other bends are also made on PVC rigid conduit.}

In making bends on PVC rigid conduit, the electrician should see to it that the internal diameter of the conduit is not reduced and damaged so that the capacity of the conduit to accommodate maximum number of conductors will not be lessen and to facilitate easy pulling of conductors.

Since PVC conduits are somewhat easier to bend than a rigid

conduit, it likewise requires patience as in any other type of conduit.

It is first pre-heated over a fire or a heat gun to a desired softness.

Little by little, it is bent to its desired shape. When such is attained, it

is then hardened by soaking it to cold or lukewarm water or

dampened with a wet rag.

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Types of Bend

1. Elbow

2. Offset bend is less than 90

o

bend, it is used when the

conduit crosses an obstacle

or when the conduit is

entering an electrical box.

3. Round saddle bend is used

when the conduit run across

circular objects like pipes.

4. Square saddle bend is used

when the conduit run across

rectangular

obstacles.

Square saddle is just a

combination of two offset

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Bend Defects

1. Burned

2. Kinks or groove

3. The diameter of the conduit

is greatly reduced due to

improper bending procedure.

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183

ACTIVITY SHEET 2.4

Bending 90

o

_{PVC Elbow}

Directions:

Your task is to perform 90

°

elbow bending of PVC pipe properly using the given supplies/materials, tools, and equipment. You should follow the procedure correctly.

Tools, Materials and Equipment Needed

Equipment:



Heat gun

1 unit

Materials:



Pencil or Chalk

1 pc



PVC pipe

1 m

Tools:



Steel meter stick/Straight edge

1 pc



Try square

1 pc



Pull and push rule

1 pc



Wet rug

1 pc

Personal Protective Equipment:



Gloves

1 pair



Respirator

1 pc

Procedures:

1. Prepare the necessary tools, materials, and equipment.

2. Wear appropriate PPE.

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Note: The greatest danger comes from vinyl chloride, a primary

component of polyvinyl chloride (PVC) and an odorless

gas, which could be released using this process. Vinyl

Chloride is a toxic carcinogen which has been proven to

cause angiosarcoma, a deadly primary liver cancer.

Use a good respirator and adequate ventilation to protect

yourself from this toxin.

Respirator

Gloves

3. Draw a right angle on the floor using your try square and chalk.

This will serve as your guide when forming your conduit into

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185

4. If you are in a room with a tiled floor, you can use it as your

guide for 90

o

_angle.

5. Draw an arc near the corner with a radius of 100 mm; this will

aid you in forming your elbow correctly.

Note: 20 mm diameter of PVC should have a radius of 100 mm as

mentioned in the previous information sheet.

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186

6. Mark off 200 mm from the end of PVC pipe. This will be the

center of your elbow bend.

7. Plug-in the heat gun and apply heat to the conduit. Apply heat

100mm on both sides of your marking. Apply heat evenly by

turning over the conduit while swaying your heat gun back and

forth to avoid kinks during bending.

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187

8. Notice that when the conduit is softening, it will sag as shown.

If the conduit is soften, turn off the heat gun and bend the PVC to the

desired shape using your arc and 90

o

_{angle guide drawn on the floor.}

9. If the desired shape is formed, damp the conduit with wet rug to

harden it immediately. (You can use your foot to hold one end

of the conduit while wiping.)

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188 Assessment Criteria Dimensions VS 5 S 3 NI 1 1. Quality: Workmanship, Appearance, Bending 90°,

2. Accuracy: Dimension, Accurate bending 3. Method: Observance of the safety measures.

Rating Scale:

VS – Very Satisfactory = 20-16 S – Satisfactory = 15-10

NI – Needs Improvement = 9 and below

ACTIVITY SHEET 2.5

PVC OFFSET BENDING

Directions: Your task is to perform offset bending of PVC pipe properly using the given supplies/materials, tools, and equipment. You should follow the procedure correctly.

Tools, Materials and Equipment Needed Equipment:

 Heat gun 1 unit

Materials:

 Pencil or Chalk 1 pc

 15 mm dia. PVC pipe 1 m

Tools:

 Steel meter stick/Straight edge 1 pc

 Try square 1 pc

 Pull and push rule 1 pc

 Wet rug 1 pc

 Gloves 1 pair

 Respirator 1 pc

Procedure:

1. Prepare the necessary tools, materials and e quipment. 2. Wear appropriate PPE.

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189

Respirator Gloves

3. Measure the elevation of the obstruction. In this case, use this wooden box.

Note: Remember, offset bent is used if the conduit crosses an obstruction. In this case, the elevation is about 70 mm.

4. Draw the depth of elevation on the floor as shown in the figure using your try square and chalk. This will guide you how high your offset bend would be.

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190

6. Mark off 100 mm from the end of PVC pipe. This will be the center of the first bend of the offset.

7. Put another mark of about 200 mm from your first marker.

8. Plug-in the heat gun and apply heat to the conduit. Apply heat between your markers. Apply heat evenly by turning over the

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191

conduit while swaying your heat gun back and forth to avoid kinks during bending.

If the conduit is softened, turn off the heat gun and bend the PVC to the desired shape using your guide drawn on the floor. Pull the left

portion of the conduit while pushing the other end.

9. If the desired shape is formed, damp the conduit with wet rug to harden it immediately. (You can use your foot to hold one end of the conduit while wiping.)

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192 Assessment Criteria Dimensions VS 5 S 3 NI 1 1. Quality: Workmanship, Appearance, Offset Bending

Rating Scale:

VS – Very Satisfactory = 20-16 S – Satisfactory = 15-10

ACTIVITY SHEET 2.6

Installing Rigid Nonmetallic Conduit

Directions: Your task is to install two bulbs controlled by two 3-way switches and one SPST switch with two convenience outlet.

TOOLS, EQUIPMENT AND MATERIALS Equipment:

 Heat gun 1 unit

Materials:

 Pencil or Chalk 1 pc

 15 mm dia. PVC pipe 3 pcs

 PVC adapter with lock nuts 18 pcs

 Utility box 5 pcs

 Junction box 4 pcs

 Lamp socket 2 pcs

 Safety switch

 15Ampere cartridge fuse

1 2 Pc pcs  3 way switch 2 pcs  SPST switch 1 pc

 1 gang plate cover 3 pcs

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193

 2 gang plate cover 2 pcs

 Conduit clamps/straps 15 pcs  Wood screws (1/4 x ½)  wiring board 50 1 Pcs pc Tools:

 Steel meter stick/Straight edge 1 pc

 Try square 1 pc

 Pull and push rule 1 pc

 Wet rug 1 pc

 Gloves 1 pair

 Respirator 1 pc

Working Drawing:

Note: Your teacher will determine the distance of each circuit.

Line diagram of the two bulbs controlled by two three-way switches and one SPST switch with two convenience outlets in different location

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194

Procedure:

1. Prepare the necessary tools, materials, and equipment. 2. Wear appropriate PPE.

3. Mark on the wiring board the location of the safety switch, utility boxes, and junction boxes.

4. Fasten the safety switch and PVC boxes with wood screws at the desired locations.

5. Prepare the PVC conduit for installation.

a. Measure and cut each PVC pipe to desired length

b. Make an offset bend at each end of PVC conduit which will be connected to a box.

c. Bend 90º based on the diagram.

6. Install and connect ends of PVC pipe to the electrical boxes, safety switch.

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195

8. Place the cover of junction box, utility box, and convenience outlet. 9. Obsreve good housekeeping.

10.Have your teacher check your work.

Assessment Criteria Dimensions VS 5 S 3 NI 1 1. Functionality: Bulbs, Convenience Outlet

2. Quality: Workmanship, Appearance, Offset Bending, Bending 90º

5. Speed: Submission on time +1, before the expected time +2, after the expected time – 2.

Rating Scale:

VS – Very Satisfactory = 25 – 18 S – Satisfactory = 17 – 10

INFORMATION SHEET 2.4

PEC PROVISION ON ELECTRICAL METALLIC TUBING

Electrical Metallic Tubing is a type of wiring installation which is designed to lessen or eliminate fire hazard and electrical accident. The following rules and regulations on the use of electrical metallic tubing should be observed: A. Application

Electrical metallic tubing may be used for exposed and concealed work at the same condition with rigid metal conduit. EMT is protected with enamel should not be used on the following conditions:

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196

Sample Electrical Metallic Tubing

a. subjected to mechanical during or after the construction b. Cinder fill

c. hazardous location

d. exposure to corrosive fumes and vapor B. Sizes

Its standard length follows the gas pipe which is 10 ft.(3m) and a diameter from ½ inch up to 6 inches(150mm).

C. Under wet location

Electrical metallic tubing can be used provided the water is prevented from entering the conduit. The support, straps and other fitting must be approved for the purpose.

D. Maximum number of conductors in tubing Trade size of conduit Wire size mm2 ½” ¾” 1” 1 ½” 2” 2.0 4 6 10 25 41 3.5 3 5 8 21 34 5.5 1 4 7 17 29 8.0 1 3 4 10 17 14.0 1 1 3 6 10

Trade size of conduit in inches Size in mm2 No. of

conductors

1/2" 2.0 4

3/4" 3.5 10

1” 6 12

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197

E. Assembly

Thread less coupling and connectors is used when tubing should be tight and should be provided with waterproof type fitting if it will be used in wet locations.

F. Types of EMT fitting (Reference: Interior and Exterior Wiring, pp. 137-138 by Feliciano Agpaoa)

Connector Coupling Adapter

Locknut Elbow Condulets

G. Type of EMT utility boxes and fitting

Utility Box Octagonal Box Clamps/Straps

H. Number of bends of EMT

The code requires a maximum of four adapter bends (360) for every one

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198

I. Types of bends

The following illustrations show the different kinds of bends used in the installation of electrical metallic tubing.

Elbow bend 90 Offset bend Saddle bend

J. Personal Protective Equipment (PPE)

Goggles Hard hat Gloves

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SELF-CHECK 2.2

ELECTRICAL METALLIC TUBING

A. Directions: On your answer sheet, write the letter of your answer. 1. It is the type of metal conduit which is designed to lessen or eliminate fire hazard.

a. EMT b. RSC c. PVC d. BX

2. It is the allowable number of quarter bends which can be done in a one run of electrical metallic conduit.

c. 4 a. 2 b.3 d. 6

3. It is a type of fitting which is used to secure EMT to metallic boxes.

a. connector b. condulets c. adaptor d. coupling 4. It is the size of conduit which can accommodate a maximum of 8 wires of 3.5mm2_wire.

a. 1” b. ½” c. ¾” d. 1 ¼”

5. It is the type of bend which makes one quarter turn.

a. offset b. elbow c. saddle d. goose neck B. Directions: Name the following conduit fittings.

6. 7.

8. 9.

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200

ACTIVITY SHEET 2.7

CUTTING ELECTRICAL METALLIC TUBING

Directions: Your task is to cut electrical metallic tubing properly using the given supplies/materials, tools, and equipment. You should follow the procedure correctly.

Supplies and Materials Pencil

Chalk EMT pipe

Tools and Equipment Metric rule

Try square Bench vise

Hack saw / pipe cutter

Personal protective equipment Gloves and goggles

Procedure:

1. Prepare the necessary tools, materials and personal protective equipment (PPE).

2. Wear the appropriate PPE.

3. Mark the length of EMT to be cut using the metric rules. 4. Cut the EMT using the hacksaw or pipe cutter.

Note: The action of the hacksaw is performed in forward stroke. The teeth of the hack saw must be

towards the handle.

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201 Assessment Criteria CRITERIA POINTS Workmanship 5 Measurement 4 Use of tool 3 Use of PPE 3 Speed 3 Housekeeping 2 TOTAL 20 ACTIVITY SHEET 2.8

BENDING ELECTRICAL METALLIC TUBING (ELBOW BEND)

Directions: Your task is to do the elbow bending of electrical metallic tubing properly using the given supplies/materials, tools and e quipment. You

should follow the procedure correctly.

Chalk EMT pipe

Try square

Hickey with handle Hack saw

Safety shoes Procedures

1. Prepare the necessary tools, materials and equipment. 2. Wear the appropriate PPE.

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202

4. Draw an arc near the corner.

5. Mark off the center of the location of the bend.

6. Insert the EMT into the conduit bender / hickey where the center of the bend is to be made.

7. Bend the EMT gradually to form a 90 bend. Check the desired shape

by placing the conduit on the layout which can be seen on step 3.

8. Remove the bender on the right angle bent EMT. 9. Observe good housekeeping.

Assessment Criteria CRITERIA POINTS Accuracy of bend 5 Measurement 4 Use of tool 3 Use of PPE 3 Speed 3 Housekeeping 2 TOTAL 20

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203

ACTIVITY SHEET 2.9

BENDING ELECRICAL METALLIC TUBING (OFFSET BEND)

Directions: Your task is to do the offset bending of electrical metallic tubing properly using the given supplies/materials, tools and e quipment. You

should follow the procedure correctly.

Chalk EMT pipe

Try square

Hickey with handle Hack saw

Safety shoes

Procedure:

1. Prepare the necessary tools, materials, and equipment. 2. Wear the appropriate PPE.

3. Measure the elevation of the box where the bend is to be fitted.

4. Draw the depth of the elevation on the floor. This will make two lines.

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204

6. Put another 200mm from your first marker.

7. Insert the hickey on the second marker and bend gradually backward stroke to follow its depth.

8. Move the hickey on the first marker and bend gradual forward stroke to follow its height.

9. Remove the hickey.

10. Observe good housekeeping. Assessment Criteria CRITERIA POINTS Accuracy of bend 5 Measurement 4 Use of tool 3 Use of PPE 3 Speed 3 Housekeeping 2 TOTAL 20

INFORMATION SHEET 2.5

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205

RIGID METALLIC CONDUIT (RMC) A rigid metal conduit serves the same

purpose as with the Electrical Metallic Tubing. It is designed to protect the electrical wiring of building from electrical hazard due to faulty wiring. It is usually installed by burying it in concrete wall floor and ceiling, in masonry or similar materials. It is also used for exposed and concealed work; it provides maximum protection when there is mechanical damage. For this wiring method to be effective, safe and

reliable, it is a must that the PEC standard and specifications is followed.

Standard size of RMC

Rigid metal conduit has smooth inside diameter. Its standard length follows the gas pipe which is 10 feet and a diameter from ½, ¾ , up to 6 inches.

Installation under atmospheric condition.

Protected by Enamel- conduit protected only with enamel is permitted only in indoor occupancies not subjected to severe corrosive influences.

Dissimilar metal – contacts of metal to another metal must be avoided in installing RMC to prevent the possibility of galvanic reaction.

Corrosion protection – conduits fitting with corrosion protection are permitted to be installed in concrete, direct earth burial, or in areas subjected to corrosive influences.

Number of conductors inside the conduit

The table on the next page shows the number of conductors permitted in a single conduit.

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206

Maximum number of conductors allowed in trade size conduit from ½ - 3 inches. Conduit trade size ½ ¾ 1 1 ¼ 1 ½ 2 2 ½ 3

Type letter Conductor size AWG TW, XHHW 14 12 10 8 9 7 5 2 15 12 9 4 25 19 15 7 44 35 26 12 60 47 36 17 99 78 60 28 142 111 85 40 171 131 62 RHW, RHH,THW 14 12 10 8 6 4 4 1 10 8 6 3 16 13 11 5 29 24 19 10 40 32 26 13 65 53 42 22 93 76 61 32 143 117 95 49 TW,THW,RHW RHH(without covering 6 4 3 2 1 1 1 1 1 2 1 1 1 1 4 3 2 2 1 7 5 4 4 3 10 7 5 5 4 16 12 10 9 6 23 17 15 13 9 36 27 23 20 14 Fittings

The following are types of conduit fittings which are usually used when wiring installation make sharp turns. The letter shows that an elbow or fitting makes right angle turn. They are:

LR L Right Condulet LB L Box Condulet

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207

Bends

Rigid metal conduit can also be bent using hickey or conduit bender. It follows the same procedure bending electrical metallic tubing.

Bending RMC using hickey Hickey

Cut

Conduit is cut with hacksaw or pipe cutter. For easy and safe way of cutting, a bench vise is recommended so that pipe can be held firmly while it is being cut.

Cutting pipe using hacksaw Pipe cutter

Ream

After cutting the pipe with hacksaw or pipe cutter, it leaves burrs. This must be removed to avoid damage of wire insulation when it is inserted in it. A reamer or round file can be used to remove burrs.

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Threads

Since rigid metal conduit is commonly used in wet places, sealing of termination can be best done if pipe is treaded. These will prevent water from entering the conduit. The use of dies and dies stock keep the end o f the pipe threaded. The sizes of dies stock range from ½ to 6 inches.

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209

SELF-CHECK 2.3

RIGID METALLIC CONDUIT

Direction: On your answer sheet, write the letter of your answer.

1. It is a process of removing sharp edges or burrs left after cutting the pipe.

a. reaming b. cutting c. bending d. installing 2. It is a type of condulet which makes conduit run turns to the

right.

a. C b. LL c. LB d. LR

3. It is the tool used to thread rigid metal conduit.

a. hickey b. dies and dies stock c. reamer d. cutter 4. It is a type of condulet which has an opening at the back.

a. C b. LL c. LB d. LR

5. It is the standard length of RMC.

a. 10 ft. b. 12 ft. c. 14 ft. d. 20 ft.

ACTIVITY SHEET 2.10

REAM CONDUIT

Chalk Rag FMT

Tools and Equipment Bench vise

Hack saw

Personal protective equipment - Gloves

- Goggles - Hardhat

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Procedure

1. Prepare the necessary tools, materials, equipment, and PPE in performing the activity.

2. Wear the appropriate PPE.

3. Measure and mark the location of cut. 4. Cut the conduit using hacksaw.

5. Ream the newly cut conduit using the flute reamer or file. 6. Put another 200mm from your first marker.

7. Check if the end of the pipe is smooth. 8. Have your teacher check your work.

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SUMMATIVE ASSESMENT:

TEST I: Knowledge and Process

Directions: Choose the letter of the correct answer and write your answer on a separate sheet of paper.

____1. In the exposed knob and tube wiring method, what is the minimum distance to be observed between conductors?

a. 4 centimeters b. 6 centimeters c. 12 centimeters d. 30 centimeters

____2. Whenever wires cross each other, what electrical materials is necessary to provide protection from injury.?

a. mica tube b. porcelain tube c. circular loom d. all of these ____3. What type of conduits is manufactured to be resistant to impact and

crushing moisture, chemical atmosphere, flame retardant and doesn’t get out of shape by heat.

a. PVC b. Rigid Nonmetallic Conduit c. Surface Raceway d. Wire ways

____ 4. How many millimeters thick of PVC should be installed under driveways and parking lots of single and two family dwelling units?

a. 460 mm b. 400 mm c. 350 mm d. 300 mm

____ 5. What is the process wherein rough edges or burrs at the cut ends of non-metallic conduit shall be trimmed inside and outside?

a. Expansion fitting b. Joints c. Securing and supports d. Trimming

____ 6. What is the maximum size of rigid nonmetallic conduit that the PEC required to be installed in wiring installation?

a. 90 mm b. 160 mm c. 150 mm d. 125 mm

____7. What type of rigid nonmetallic conduit is one of the most commonly used conduits in electrical wiring installation today?

a. Polyvinyl chloride c. Rigid nonmetallic conduit b. Plastic molding d. Wire ways

____8. What type of bend is used when the conduit runs across circular object like pipes?

a. Elbow bend b. Offset bend c. Round saddle bend d. Square saddle bend

____9. What is used as mechanical protection for electric conductors, has a smooth interior and a wall of non-conducting fibrous material? a. Electrical metallic conduit b. Porcelain knob & tube

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----10. What is the process by which jointing between lengths of conduit and between conduit couplings, fittings and, boxes shall be made with approved coupling and adapter?

a. Expansion fitting b. Joints c. Securing and supports d. Trimming

Test: II - Understanding Test

Directions: Below are unarranged procedures in Bending 90°PVC Elbow. Arrange them in proper order. Write your answer on a separate sheet of paper.

o

Mark off 200 mm from the end of PVC pipe. This will be

the center of your elbow bend.

o

Observe good housekeeping.

o

Prepare the necessary tools, materials and equipment.

o

Draw a right angle on the floor using your try square and

chalk. This will serve as your guide when forming your

conduit into 90

o

_angle.

o

Wear appropriate PPE.

o

If you are in a room with a tiled floor, you can use it as

your guide for 90

o

_angle.

o

Plug-in the heat gun and apply heat to the conduit. Apply

heat 100mm on both sides of your marking. Apply heat

evenly by turning over the conduit while swaying your

heat gun back and forth to avoid kinks during bending.

o

Draw an arc near the corner with a radius of 100 mm;

this will aid you in forming your elbow correctly.

o

Notice that when the conduit is softening, it will sag.

o

If the desired shape is formed, use a wet rag to cool down

the conduit to immediately. (You can use your foot to hold

one end of the conduit while wiping.)

Test.III – Performance Test:

Installing Simple Electrical Circuit (10 points)

Directions: Your task is to install simple electrical circuit, a lamp controlled by a single pole switch. Use rigid nonmetallic conduit (RNC). Tools, Materials and Equipment Needed:

1 pc Installation plan/working drawing 1pc Incandescent lamp 25watts

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1 pc SPST switches (flush type) 1 pc 1 gang switch plate

2 pcs Junction boxes metal/plastic 1 pc Utility boxes metal/plastic

1 pc Rigid nonmetallic conduit ½”diameter

2 pcs RNC clamps

3 meters Solid/stranded wire 1.6mm 6 pcs Flat head screws 3.4”

1 roll Electrical tape 1 set Line cord

1 pc Wiring board 1’ x 2’ x ½” Tools, equipment and Instrument Needed Combination, long nose, and side cutting pliers Flat and Philips screw drivers

Gloves