Observation

          2(a): The majority of the candidates accurately listed the factors that affect earth resistance.
2(b): Candidates' performance on the requirement of IEE regulations for trunking installation was average.
2(c): The candidates displayed a moderate level of proficiency in identifying the factors contributing to accidents in a temporary installation.
2(d): Most candidates were unable to provide an explanation for single phasing.
2(e): Candidates demonstrated proficiency in identifying marking out tools commonly used in electrical installation.
2(f): Most of the candidates demonstrated an understanding of the concept of soldering.
           

         
Expected response:
(a)           FACTORS THAT INFLUENCE EARTH RESISTANCE

1. Condition/environment of the soil/resistivity
2. Temperature of the soil
3. The moisture content of the soil
4. Size spacing of the earth electrode
5. Material of the conductor
6. Quality of the soil coal/dust and charcoal in the earth electrode pits
7. (b).REQUIREMENTS OF IEE REGULATIONS ON TRUNKING INSTALLATION

1. Trunking must be securely fixed and adequately protected against mechanical damage
2. All joints in the trunking system must be mechanically sound
3. Entries to trunking must be protected against the inflow of water/moisture
4. A continuous partition must be used in a condition where low voltage and main voltage are run in the same trunking
5. A maximum space factor of 45% is required in trunking
6. Earthing must be effective
7. It must be IP4X compliant
8. Where trunking pass through ceiling or partitions, the hole should be plugged/sealed

(C) CAUSES OF ACCIDENT IN A TEMPORARY INSTALLATION

1. Carelessness
2. Ignorance
3. Skylarking
4. Horseplay
5. Usage of wrong tools
6. Wet floor
7. Not using protective equipment
8. Exposure to live wire
9. Lack of protective coverage/use of cable without mechanical protection
10. Over loading of the existing circuit
11. Over confidence
12. Fatigue

(d) EXPLANATION OF SINGLE PHASING

-           It is an effect produced when an open circuit occurs on one of the line conductors supplying a 3- Phase motor.
OR      When one of the lines of a motor is not connected, resulting on the motor running on a single phase. When this happens, current across the two remaining lines can go as high as 1.73 times the normal circuit.

(e)TOOLS FOR MARKING OUT

1. Calipers                                               -           Steel rule
2. Chalk                                                   -           Try square
3. Surface plates                                      -           Measuring tape
4. Angle plates                                        -           Sliding level
5. Height gauge/surface gauge               -           Pencil
6. Protractor                                            -           Chisel
7. Centre punch                                      -          Scriber
8. Dividers

(f) (i)        DEFINITION OF SOLDERING

It is the process of joining metals together with the use of heat and alloy of solder

1. METHODS OF SOLDERING

1. Pot and ladle method
2. Blow lamp
3. Soldering bit method
4. Stick method

2. ITEMS USED IN SOLDERING ELECTRICAL JOINTS

1. Plier
2. Soldering bit/iron
3. Flux
4. Solder
5. Blow lamp
6. Pot and ladle
7. Gas touch
8. Vero board
9. Soldering gun
10. Soldering lead
11. Soldering station
12. Soldering wick