Eim Ncii Lmg9 p147-217 - PDFCOFFEE.COM (2024)

QUARTER IV

Time Allotment: 40 Hours

LESSON: INSTALLING ELECTRICAL OUTLETS AND LIGHTING FIXTURES

LIGHTING

SYSTEMS,

AUXILIARY

I.INTRODUCTION: This module contains the “know” and “do” practices in Installation of Electrical Lighting System on Auxiliary Outlets and Lighting Fixtures. It covers the knowledge, skills and attitudes required in installing the lighting fixtures. Specifically, this module covers installation of knob and tube, PVC raceway/molding, rigid non-metallic conduit, and flexible non-metallic conduit. This module consists of Learning Outcomes (LO’s) that contain learning 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 that you have already read and understood the information/activity sheet and answered correctly the self-check provided in the Learning Activities. II. LO2- INSTALLING ELECTRICAL LIGHTING SYSTEMS, AUXILIARY OUTLETS AND LIGHTING FIXTURES 1.

Select appropriate electrical tools, equipment, and materials for specific tasks

2.

Apply suitable wiring method for the job

3.

Install electrical wiring systems using different types of wiring methods: 

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

Circuit using 3-way switches in two locations

Combination of lighting and convenience

147

III. PRE/DIAGNOSTIC ASSESMENT: TEST I: Directions: Choose the correct answer. Write the letter of your answer on a separate sheet of paper. ____1. What types of wiring method is commonly found in old homes? a. open wiring b. open knob and tube wiring c. concealed wiring d. none of these ____2. In installing an electrical wiring system with the exposed knob and tube wiring method, what is the minimum distance between conductors that should be maintained ? a. 4 centimeters b. 6 centimeters c. 12 centimeters d. 30 centimeters ____3. The exposed knob and tube wiring method, requires that the knobs must be _____ centimeters apart? a. 4 centimeters b. 6 centimeters c. 12 centimeters d. 30 centimeters ____4. Whenever wires cross each other, what electrical materials are necessary to provide protection from injury? a. mica tube b. porcelain tube c. circular loom d. all of these ____5. What type of switching controls a bulb in two different locations? a. Three-way switch b. Switchgear c. Four-way switch d. single pole switch ____6. This type of conduit is manufactured to be resistant to impact and crushing moisture, chemical atmosphere, flame retardant or not easily burned and get out shape by the heat. a. PVC b. Rigid Nonmetallic Conduit c. Surface Raceway d. Wire ways ____7. What is the minimum burial depth of PVC buried underground in a 50 mm

thick concrete trench? a. 15 millimeters b. 30 millimeters

c. 50 millimeters d. 300 millimeters

____8. What is the minimum burial depth of PVC directly buried under driveways

and parking lots of single and two family dwelling units ? a. 460 mm b. 400 mm c. 350 mm

d. 300 mm

____9. What is the minimum burial depth of PVC directly buried under airport

runways, including adjacent areas where trespassing is prohibited ? a. 460 mm b. 400 mm c. 350 mm d. 300 mm

____10. 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

148

d. Trimming

INFORMATION SHEET 2.1 PRINCIPLES OF KNOB AND TUBE

The open or exposed wiring method is sometimes referred to as 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. 2. 3. 4. 5.

Commercial Garages Theaters Motion Picture Studious Hoist ways 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: The Split and Solid knobs

Split knobs are used to support wires smaller than No. 8. 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). 149

Height of Knob

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

150

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.

30 cm. 1 Ft.

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.

151

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. 4. Use the right-sized screw driver for the right size of screw. 152

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

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

mica tubing or loom

153

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.

154

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

1

roll

electric tape

1

pc

safety switch/cut out

1

pc

4’ x 4’ x ¾” wiring board

mica tubing or loom

155

II. Pictorial Wiring Diagram

One bulb, controlled from two locations by two 3-way switch using plastic/porcelain knob and tube

156

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 1. Functionality: Bulb 2. 3. 4. 5.

Quality: Workmanship, Appearance Accuracy: Dimension, Accurate bending Method: Observance of the safety measures. 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 NI – Needs Improvement = 9 and below

157

VS 5

S 3

NI 1

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.

158

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 maintenance.

is

required

for

installation,

operation,

or

(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): (a) 15mm (20 mm) to 100mm (110mm) inclusive 159

(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

Flexible Nonmetallic Conduit 160

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 Materials: o Pencil or Chalk o Installation plan or working drawing o Flat head screw, ¾ in X 10 o *Fisher, # 6 (tox) o Flexible nonmetallic tubing o Mica tube, ¼ in. dia. o Stranded wire, 2.0 mm2 TW o Safety switch, 30 A o Guide wire Tools: o Pull and push rule or any measuring device suited for the activity o Steel meter stick/Straight edge Personal Protective Equipment: o Safety glass o Gloves o Goggles o Safety shoes 161

-

1 unit 1 unit

-

1 pc 1 pc 15 pcs 15 pcs 5 mts 1 mts 10mts 2 pcs 3m

-

1 pc

-

1 pc

-

1 1 1 1

pc pair pc pair

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.

162

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 of conductors.

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

10. Lay out the tubing with conductors permanently.

163

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

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

13. Insert the connector.

14. Secure the tubing to the raceway on the indoor unit.

164

15. Put the lock nut and tighten it.

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

17. Terminate the conductors. It is indicated in the manufacturer’s manual how to terminate the conductors.

18. Be sure that the connections are tightened correctly.

165

19. 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 main supply line is usually pre-wired by the manufacturer, all you have to do is to terminate it from the circuit protection.

20. Terminate to the circuit protection.

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

166

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.

4. 5.

167

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 Safety Shoes

168

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 center junction box to the lamp holder box then the switch utility box. 169

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.

CRITERIA FUNCTIONALITY WORKMANSHIP a. Wire Terminations b. Dimension, Mounting and Presentation

Sample Performance Assessment Rubrics 5 POINTS 3 POINTS I POINT Lamp lights Lamp lights but Lamp does not flickers light All wire One of the wire Two or more wire terminations are terminations is terminations are perfectly done. imperfectly done. imperfectly done. Dimensions - There is an There are are perfect error in either errors in both All boxes are dimensions or dimensions & properly mounting of mounting of mounted and boxes boxes secured - Finished Finished - Finished output is output is messy output is clean quite messy 170

PROCESS

TIME MANAGEMENT

Criteria

and neat The procedure was followed from start to finish / correct usage of tools/safety work habits. Work was done ahead of time.

The procedure was partly followed/ correct usage of tools/safety work habits Work was done just in time. -

Score Sheet: Group 1 Group 2

-

Did not follow the procedure/ correct usage of tools/safety work habits

Unable to finish the work.

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 21-25 16-20 11-15 6-10 1-5

Descriptive Excellent Very Good Good Fair Needs improvement

Numerical 99 95 90 85 75

171

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 (S4w) and two 3-way (S3w) 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: Materials and Supplies Needed Quantity Description 1 pc Pencil or chalk 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 Hammer Wire Stripper Pull push rule/meter stick Personal Protective Equipment (PPE) Safety glasses Gloves Safety Shoes

172

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

173

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.

CRITERIA FUNCTIONALITY WORKMANSHIP Wire Terminations Dimension, Mounting and Presentation

PROCESS

TIME MANAGEMENT

Sample Performance Assessment Rubrics 5 POINTS 3 POINTS Lamp lights Lamp lights but flickers All wire One of the wire terminations are terminations is perfectly done. imperfectly done. Dimensions - There is an are perfect error in either All boxes are dimensions or properly mounting of mounted and boxes secured - Finished output - Finished output is is clean and quite messy neat The The procedure was procedure was followed from partly followed/ start to finish correct usage of / correct usage tools/safety of tools/safety work habits work habits. Work was done Work was done ahead of time. just in time.

I POINT Lamp does not light Two or more wire terminations are imperfectly done. There are errors in both dimensions & mounting of boxes Finished output is messy

-

Did not follow the procedure/ correct usage of tools/safety work habits

Unable to finish the work.

174

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 21-25 16-20 11-15 6-10 1-5

Descriptive Excellent Very Good Good Fair Needs improvement

Numerical 99 95 90 85 75

175

INFORMATION SHEET 2.3 RIGID NONMETALLIC CONDUIT (RNC) Rigid Nonmetallic Conduit (RNC) is non-metallic unthreaded smoothwalled 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 6. In dry and damp locations

176

The Philippine Electrical Code prohibits the use of rigid non-metallic conduit under the following conditions: 1. 2. 3. 4.

Hazardous (Classified) locations Support of fixtures Where subject to physical damage unless identified for such use. Where subject to ambient temperatures in excess of 50oC 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

Maximum Spacing

[mm (mm)]*

Between Supports (mm)

15 (20) – 25 (32)

900

32 (40) – 50 (63)

1500

65 (75) – 80 (90)

1800

90 (100) – 125 (135)

2100

150 (160)

2400

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

177

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

100

20

125

25

150

32

200

40

250

50

300

65

375

80

450

90

525

100

600

125

750

150

900

178

TYPES OF PVC CODUIT FITTINGS

PVC Coupling

PVC elbow

Adapter

PVC Conduit Pipe

PVC 2G box

LL Access Fitting

1 Inch Type T Condulet

1/2 Inch Type T PVC Condulet

179

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. 180

Types of Bend

1. Elbow

2. Offset bend is less than 90o 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 bends.

181

Obstacle e

Bend Defects

1. Burned

2. Kinks or groove

Kinks

3. The diameter of the conduit is greatly reduced due to improper bending procedure.

182

ACTIVITY SHEET 2.4 Bending 90o 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 Materials: 

1 unit

Pencil or Chalk

 PVC pipe Tools: 

1 pc 1m

Steel meter stick/Straight edge 1 pc 1 pc Try square

Pull and push rule

 Wet rug Personal Protective Equipment:

1 pc 1 pc

Gloves

1 pair

Respirator

1 pc

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

183

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 90o angle.

184

4. If you are in a room with a tiled floor, you can use it as your guide for 90o 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.

100 mm

185

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.

186

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 90o 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.)

10. Observe good housekeeping. 187

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. 4. Speed: Submission on time +1, before the expected time +2, after the expected time – 2. 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 Materials:  Pencil or Chalk  15 mm dia. PVC pipe Tools:  Steel meter stick/Straight edge  Try square  Pull and push rule  Wet rug Personal Protective Equipment:  Gloves  Respirator Procedure: 1. Prepare the necessary tools, materials and equipment. 2. Wear appropriate PPE. 188

1 unit 1 pc 1m 1 1 1 1

pc pc pc pc

1 pair 1 pc

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.

5. You should have two lines as shown in the figure. 189

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 190

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.)

10. Your bend should look like this.

191

Assessment Criteria VS 5

Dimensions

S 3

NI 1

1. Quality: Workmanship, Appearance, Offset Bending 2. Accuracy: Dimension, Accurate bending 3. Method: Observance of the safety measures. 4. Speed: Submission on time +1, before the expected time +2, after the expected time – 2. Rating Scale: VS – Very Satisfactory = 20-16 S – Satisfactory = 15-10 NI – Needs Improvement = 9 and below

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 Materials:  Pencil or Chalk  15 mm dia. PVC pipe  PVC adapter with lock nuts  Utility box  Junction box  Lamp socket  Safety switch  15Ampere cartridge fuse  3 way switch  SPST switch  1 gang plate cover  Convenience Outlets 192

1 1 3 18 5 4 2 1 2 2 1 3 2

unit pc pcs pcs pcs pcs pcs Pc pcs pcs pc pcs sets

   

2 gang plate cover Conduit clamps/straps Wood screws (1/4 x ½) wiring board

2 15 50 1

Tools:  Steel meter stick/Straight edge  Try square  Pull and push rule  Wet rug Personal Protective Equipment:  Gloves  Respirator

pcs pcs Pcs pc 1 1 1 1

pc pc pc pc

1 pair 1 pc

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

S3 w

S3 w

S

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

193

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. 7. Support the conduit with conduit clamps or straps.

194

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 VS 5

Dimensions

S 3

NI 1

1. Functionality: Bulbs, Convenience Outlet 2. Quality: Workmanship, Appearance, Offset Bending, Bending 90º 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 NI – Needs Improvement = 9 and below

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:

195

Sample Electrical Metallic Tubing a. b. c. d. B.

subjected to mechanical during or after the construction Cinder fill hazardous location exposure to corrosive fumes and vapor 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 ½” ¾” 1” mm2 2.0 4 6 10 3.5 3 5 8 5.5 1 4 7 8.0 1 3 4 14.0 1 1 3 Trade size of conduit in inches

Size in mm2

1/2" 3/4" 1” 1 ½”

2.0 3.5 6 2

196

1 ½”

2”

25 21 17 10 6

41 34 29 17 10

No. of conductors 4 10 12 12

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.

G.

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

Connector

Coupling

Adapter

Locknut

Elbow

Condulets

Type of EMT utility boxes and fitting

Utility Box H.

Octagonal Box

Clamps/Straps

Number of bends of EMT

The code requires a maximum of four adapter bends (360) for every one run of tubing.

197

I.

Types of bends

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

Obstacle

Elbow bend 90 J.

Offset bend

Saddle bend

Personal Protective Equipment (PPE)

Goggles

Hard hat

198

Gloves

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.

10.

199

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.

5. Observe good housekeeping.

200

Assessment Criteria CRITERIA Workmanship Measurement Use of tool Use of PPE Speed Housekeeping TOTAL

POINTS 5 4 3 3 3 2 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 equipment. You should follow the procedure correctly. Supplies and Materials Pencil Chalk EMT pipe Tools and Equipment Metric rule Try square Hickey with handle Hack saw Personal protective equipment Gloves and goggles Safety shoes Procedures 1.

Prepare the necessary tools, materials and equipment.

2.

Wear the appropriate PPE.

3.

Draw right angle bend on the floor using the try square.

201

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 Accuracy of bend Measurement Use of tool Use of PPE Speed Housekeeping TOTAL

POINTS 5 4 3 3 3 2 20 202

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 equipment. You should follow the procedure correctly. Supplies and Materials Pencil Chalk EMT pipe Tools and Equipment Metric rule Try square Hickey with handle Hack saw Personal protective equipment Gloves and goggles Safety shoes Procedure: 1. 2.

Prepare the necessary tools, materials, and equipment. 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.

5. Mark off 100mm from the end of the pipe.

203

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 Accuracy of bend Measurement Use of tool Use of PPE Speed Housekeeping TOTAL

POINTS 5 4 3 3 3 2 20

INFORMATION SHEET 2.5 204

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.

205

Maximum number of conductors allowed in trade size conduit from ½ - 3 inches. Conduit 1 1 ½ ¾ 1 2 2½ 3 trade size ¼ ½ Conductor Type letter size AWG TW, XHHW 14 9 15 25 44 60 99 142 12 7 12 19 35 47 78 111 171 10 5 9 15 26 36 60 85 131 8 2 4 7 12 17 28 40 62 RHW, 14 6 10 16 29 40 65 93 143 RHH,THW 12 4 8 13 24 32 53 76 117 10 4 6 11 19 26 42 61 95 8 1 3 5 10 13 22 32 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

LL L Left Condulet

C Condulet 206

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.

207

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 of the pipe threaded. The sizes of dies stock range from ½ to 6 inches.

Dies and dies stock

Tripod with pipe cutter

208

Die and dies stock set

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.

ACTIVITY SHEET 2.10 REAM CONDUIT Supplies and Materials Pencil Chalk Rag FMT Tools and Equipment Bench vise Hack saw Personal protective equipment - Gloves - Goggles - Hardhat

209

d. 20 ft.

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. Note : ( Your teacher will demonstrate the proper way of reaming)

210

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 c. Rigid nonmetallic conduit d. Flexible nonmetallic conduit 211

----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 90o angle. o Wear appropriate PPE. o If you are in a room with a tiled floor, you can use it as your guide for 90o 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: 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 212

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 Hammer Wire Stripper Pull push rule/meter stick Personal Protective Equipment (PPE) Safety glasses Gloves Safety Shoes

213

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. Mount the utility and junction boxes to its proper position, using two screws per box. 4. Attach flexible connectors and insert the flexible tubing from the center junction box to lamp holder box and switch utility box. 5. Insert solid wires (TW 1.6mm./#14awg) through flexible tubing from the center junction box to the: 6. Remove the insulator of wires inside the utility and junction boxes. 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. 214

TECHNICAL TERMS: Electrical Metallic Tubing is a type of wiring installation which is designed to lessen or eliminate fire hazard and electrical accident. Electrical Wiring Plan is a technical representation of electrical system proposed to be installed in building or house. It includes material, devices and equipment. Floor Plan is a plan of a room or floor of a building drawn to scale as if viewed from above. Legend shows the meaning of each symbol used in the electrical plan.

Offset bend is less than 90o bend, and it is used when the conduit crosses an obstacle or when the conduit is entering an electrical box. Polyvinyl chloride (PVC) 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 Riser Diagram is a single line diagram presentation of the entire electrical circuit from the service entrance up to the smallest circuit branch.

Round saddle bend is used when the conduit runs across circular objects like pipes. Solid knobs are used to support or anchor wires as big as No. 8 or bigger. Split knobs are used to support or anchor wires smaller than No. 8. Screws or nails may be used to fasten the knobs. Square saddle bend is similar to round saddle. It is used when the conduit run across rectangular obstacles. Square saddle is just a combination of two offset bends. Surface Raceway is a one piece, nonmetallic, adhesive backed latching raceway designed to aesthetically organize and route low voltage communications cables. Troubleshooting is problem detecting and solving, often applied to repair defective gadgets or products like fluorescent lamp fixtures. It is a systematic search for the source of a problem so that it can be repaired so that the gadgets or products will be functional. 215

REFERENCES: 1. Azares, Efren F. and Recana, Cirilo B. Practical Electricity III; Adriana Publishing: 1999. 2. Agpaoa, Feleciano. Interior and Exterior Wiring Troubleshooting; National Bookstore: 1991. 3. Fajardo, Max B. Electrical Layout and Estimate. 5138 Merchandising. Copyright 2000. 4. Johnston, Larry et.al., Better Homes and Gardens Wiring 1 st Edition, Meredith Books; 5. Max B. Fajardo Jr. & Leo R. Fajardo. Electrical Layout and Estimate, 2nd Edition. Philippine Copywrite 2000 by 5138 Merchandising 6. Mulin, R.C., Smith R.L. Electrical Wiring-Commercial, Six Ed., New York: Delmar’s Publishing Inc.; 1984, pp. 7. www.diydata.com/tool/drills/drills.php: 8. www.powertoolinstitute.com: 9. www.technologystudent.com 10. www.epa.gov/rtp/new-bldg/environmental/0910updf :

11. www.omnicontrols.com/: 12. www.wikihow.com/: 13. www.acmehowto.com/howto/maintenance/electrical/:

216

Eim Ncii Lmg9 p147-217 - PDFCOFFEE.COM (2024)

References

Top Articles
Latest Posts
Recommended Articles
Article information

Author: Annamae Dooley

Last Updated:

Views: 5806

Rating: 4.4 / 5 (65 voted)

Reviews: 88% of readers found this page helpful

Author information

Name: Annamae Dooley

Birthday: 2001-07-26

Address: 9687 Tambra Meadow, Bradleyhaven, TN 53219

Phone: +9316045904039

Job: Future Coordinator

Hobby: Archery, Couponing, Poi, Kite flying, Knitting, Rappelling, Baseball

Introduction: My name is Annamae Dooley, I am a witty, quaint, lovely, clever, rich, sparkling, powerful person who loves writing and wants to share my knowledge and understanding with you.