This Question Paper Consists of 6 Pages

Exemplar-1-NC(V) 2009

ELECTRICAL WORKMANSHIP LEVEL 4

ELECTRICAL WORKMANSHIP

NQF LEVEL 4

2009

(********)

(X-Paper)

09:00 – 12:00

EXEMPLAR

This question paper consists of 6 pages.

TIME: 3 HOURS
MARKS: 100
______
NOTE: / If you answer more than the required number of questions, only the required number of questions will be marked. All work you do not want to be marked must be clearly crossed out.

INSTRUCTIONS AND INFORMATION

1.
2.
3.
4.
5. / Answer ALL the questions in SECTION A and choose ONE question from SECTION B.
Read ALL the questions carefully.
Number the answers according to the numbering system used in this question paper.
Use  = 3.142
Write neatly and legibly.

SECTION A

QUESTION 1: TYPICAL ELECTRICAL INSTALLATIONS

1.1 / Illustrate, by means of a sketch, how you will connect a geyser circuit. The sketch should include the connection from the distribution board. / (4)
1.2 / Briefly describe the practical uses of the following:
1.2.1 / Transformer / (1)
1.2.2 / Relay / (1)
1.2.3 / Piezo transducer / (1)
1.3 / A resistor of 15 ohms, an inductor of 100 mH and a capacitor of 150F are connected in parallel. This circuit is connected to a 200V, 60Hz supply. Calculate the following:
1.3.1 / Inductive reactance / (2)
1.3.2 / Capacitance reactance / (2)
1.3.3 / Current through all the branches / (3)
1.3.4 / Total current / (2)
1.4 / Explain electromagnetic induction. / (2)
1.5 / Regulation 5.2.2 in SABS 0142 (SANS 1-10142) focuses on volt drops.
Briefly discuss Regulation 5.2.2. / (2)
[20]

QUESTION 2: DOMESTIC APPLIANCES

2.1 / Name THREE types of space heaters / (3)
2.2 / Draw circuit diagrams for the connection of a three heat switch to a stove plate to operate on: OFF, LOW, MEDIUM and HIGH heat. / (4)
2.3 / Explain the procedure for replacing the element of a geyser. / (5)
2.4 / What does Regulation 6.16.3.1.2 stipulate with regard to the installation of a switch-disconnector for a fix cooking appliance(s)? / (5)
2.5 / Earthing is compulsory for electrical installation as per SABS 0142 (SANS 1-10142). List THREE conditions in a bathroom where earth is not needed if the appliances are electrically isolated. / (3)
[20]

QUESTION 3: LOW VOLTAGE TRANSFORMER AND SWITCHGEAR

3.1 / Why is it important to plan in advance? Give THREE reasons of the importance of planning in advance. / (3)
3.2 / State the general procedures applicable to worksites. / (5)
3.3 / What is the purpose of the induced-voltage test on transformers? / (2)
3.4 / Draw a fully labelled schematic sketch of a general contactor layout. / (5)
3.5 / Explain the advantages of symbolic safety signs in industry. / (4)
3.6 / Why must a distribution board be easily accessible? / (1)
[20]

QUESTION 4: ELECTRICAL MACHINES AND CONTROL GEAR

4.1 / As a technician, you are requested to install a single-phase motor. Describe the steps to follow for commissioning this single-phase capacitor start motor until handover to a company. / (9)
4.2 / The table below shows some simple tests that can be done on a control gear. Complete the table by indicating the type of tester or measuring equipment used.
Measurement/Testing / Testing/Measuring equipment
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5 / Protection against direct contact
Clearance and creepage distances
Heat resistance
Abnormal heat and fire
Rated load current / A
B
C
D
E
(5)
4.3 / Certain tasks which involve a source of ignition require a hot-work permit. State THREE conditions required to issue a hot-work permit. / (3)
4.4 / Indicate whether the following statements are TRUE or FALSE. Write only 'true' or 'false' next to the question number (4.4.1 - 4.4.3) in the ANSWER BOOK.
4.4.1 / Lockout is the use of a lock to make machinery or equipment inoperable or to isolate an energy source. / (1)
4.4.2 / Tag-outs are not considered good practice. / (1)
4.4.3 / Emergency stop buttons or electrical interlocks can be used to routinely stop machinery as the only method of lockout. / (1)
[20]
TOTAL SECTION A: / 80

SECTION B

QUESTION 5: SAFETY AND FIRST AID

5.1 / There are many factors that contribute to hazardous conditions in the workplace. Explain THREE common examples of hazardous conditions in the workplace. / (3)
5.2 / State FOUR safety precautions to be taken when arc welding. / (4)
5.3 / What are the possible results of electric shock? / (4)
5.4 / Discuss any THREE provisions of the Occupational Health and Safety Act of 1993 (OHSA of 1993). / (3)
5.5 / As a member of a delegation, you visit a construction site and find safety lacking. Develop a risk control plan that takes into account the hierarchy of controls as per the risk assessment. / (6)
[20]

QUESTION 6: ELECTRICAL ENTREPRENEURSHIP

6.1 / State and explain a few constraints during the setting up/starting of a business of your own. / (5)
6.2 / You need to enter into a partnership. What legal information is needed to formalise this type of business? / (7)
6.3 / Design your own company logo and place it on the letterhead of your business stationery. The letterhead must include the following details:

Address (physical and postal)
E-mail address
Telephone numbers
Fax numbers

/ (8)
[20]
TOTAL SECTION B: / 20
GRAND TOTAL: / 100