ATE1112 – Electrical Installation

Revision sheet (MT1 – Exam – Module 2 & 3)

NOTE: Solution in Red

1. Circle the correct answer:a. A wiring System Includes all except

i. Wiresii. Protective cover

iii. meteriv. insulated cover

b. A protective cover is made of

i. Plasticii. Rubber

iii. Steel or aluminumiv. all of the above

c. Cables are usually made of

i. Conductorii. Copper

iii. Woodiv. i & ii

d. The following devices need to be connected for safe and reliable distribution of the power within the building except

i. MDBii. Lamp

iii. Junction Boxiv. Electricity meter

e. ……………………Is the first protective component in the electrical installation of a building.

i. MDBii. Fuses

iii. Junction Boxiv. Electricity Meter

f. …………………… is a metal rail with hat- shaped cross section.i. Fuses

ii. Din Rail iii. Conduitsiv. None of the above

g. To measure current using a DMM:i. The DMM must be connected across or in parallel with the component

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ii. The circuit must be broken and the DMM connected In series.iii. We use the DMM on the power source.iv. None of the above.

2. True/Falsea. The thickness of the wire depends on the current it needs to

carry. (T / F)b. Single-phase power system is used at home. (T / F)c. Three phase power systems are used at office and buildings (T / F)d. The Mains Distribution Boxes may have more than one main switch. (T / F)e. Some appliances will only have two wires - Live & Neutral. They are 'Double

Insulated' and do not depend upon the Earth wire for protection. (T / F)

3. Name the wires used in Single phase and mention the color of each:a.b.c.

4. Identify the parts of the following plug

5. Name the following tools and their usage

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6. What is the ground / earth wire used for? Is it always there in each plug of a single-phase power?

7. The number of terminals on the meter depends on:a. The type of the meterb. The manufacturer

8. Name the following parts and use arrows to show their proper place:

1. 2. 3.

9. Define the following:a. Continuity Test:

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Is done using the multimeter diode function which provides a beep when continuity / short circuit is present. Which is used to detect if any of the three Live, neutral or earth wires are connected by mistake and to make sure the wires are connected properly to their places.

b. Potential Equalizer

10. Name each device/ component with its function (solution In red)

Main SwitchThis switch turns the power for the entire building ON or OFF.

Electricity MeterWhich gives the reading of the electricity used in a house, office or apartment.

Din RailIs used to mount CB and control devices

RCD: Residual Current DeviceProtects human beings against direct or indirect contact and against fire due to earth leakage faults.

MDB: Main Distribution box

The device with which power distribution and installation protection is achieved.

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ConduitsThe conduit is a connected length-to-length or to electrical box with suitable compression or screw fittings.

FusesProtect the electrical installation from overloading.

JB: Junction Box to mount devices, conduits and

cables; to protect people from electric

shock; to keep exposed conductors away

from explosive building materials.

CB: Circuit Breaker

Protect the installation against over-current or short circuit.

11. Which cable could carry more current (why)?

12. Connect the following meter according to the connection Diagram:

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Solution (memorize both diagrams)

Why is the above meter specified as single phase?

The connection scheme indicates that this particular meter is a single-phase meter as only one pair of incoming/outgoing live conductors are connected.

13. Identify the components of the box shown below:

14. What is the name of the device below and why do we use it?

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Potential Equalizer, it is used to connect all metal-based installation to ground/ earth in order to avoid accidents of unwanted current flow.

15. Fill in the table below with the correct values:

Fuse Rating of Appliances

Standard Fuse Ratings

Upto 700WBetween 700W and 1200W

Over 1200W

16. Name each of the following processes:

Fix the Din Rail inside the MDB

Fix the Circuit breaker on the Din Rail

Use the Bubble/spirit level to check the alignment vertically and horizontally

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Mark holes on the wooden board and use drilling machine and fix it with ¾ screws.

Cut the conduits 15 cm using hacksaw

Fix the adaptor to the conduit

Screw the adaptor to the MDB

Screw the adaptor to the switch box

Fix a TEE box between the MDB and the Switch box

Connect an elbow at the end of the PVC conduit

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Run the Neutral and ground wires through the conduits

Connect a live wire to the switch box

Connect the one-gang one way switch at the switch box.

Fix the switch

Connect live, neutral and earth wires to the lamp holder

Fix the lamp holder.

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17. Name the following:Hacksaw

TEE box

Elbow

Spirit level / bubble level

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Saddle

18.In case the lamp did not work the following must be done:

i. Lamp must be removed while the switch is ONii. Connect the tester (diode function – multimeter) to the lamp

socket and the other to the ground.iii. If the connection is fine check the same way with:

1. Bulb terminal on switch2. MDB terminal of the switch3. Live MDB connection

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iv. Replace the lamp or switch if required.

19. Compare between the installation diagram and the wiring diagram:

20.DO exercises on page 7, 11 in module 3 and remember to memorize the table of parts and symbols.

Good Luck

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