2330 level 3 smartscreen questions/answers

[m4tty]

#SmartScreen

Level 3 Certificate in Electrotechnical Technology Unit 5 Sample question answers

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#Unit 5: Electrical maintenance: fault diagnosis and rectification

Sample questions

Answer guide

1. Describe three safe working actions that should be followed prior to undertaking fault

diagnosis on a suspected faulty electric motor.

Solution

a. Ensure that the isolator in the motor circuit is switched to the OFF position and locked off. (2 marks)

b. Verify that the motor is isolated from the supply by using a voltage indicator.

(2 marks)

c. Post warning notices at the motor isolator and starter, indicating that maintenance and/or repair work is taking place. (2 marks)

2. Describe three stages in the process of fault diagnosis and rectification of industrial electrical equipment.

Solution

a. Collect information on events leading up to the fault from operators/supervisors in

the industrial premises. (2 marks)

b. Collect information from written reports and maintenance records relating to the faulty equipment. (2 marks)

c. Carry out the necessary electrical repairs. Carry out functional checks after repairs have been completed and re-commission if all checks are satisfactory. (2 marks)

3. Describe two common faults that may occur in each of the following:

a. wiring systems

b. luminaires

c. flexible chords and cables

Solution

Wiring systems

 

[m4tty]

3. Identify six faults which may occur in a Motor starter and control circuit.

Solution

Any from: faulty overload, pinched/broken/short circuited wiring. Burnt out contacts, open circuited coil, missing link, contacts stuck open/closed. Or suitable alternatives.

(6 marks)

4. A request is received to look at a single phase capacitor start motor which, having worked satisfactorily for a number of years, now fails to rotate. The motor drives a chilling unit via v belts.

Describe the logical sequence to be used to diagnose the fault.

Solution

1. Obtain information from operators as to the time of fault and any other information

2. Analyse the information supplied

3. Check supply to switchgear.

4. Check continuity of motor windings

5. Check capacitor and connections

6. Check motor is free to rotate

Or suitable alternatives (6 marks)

5. State three factors which would decide whether a piece of equipment would be repaired or replaced after developing a significant fault or damage.

Solution

Any two from cost, availability of replacement, downtime/lost production, legal responsibility

 

[eren]

u the best man!

 

[aceandy2]

brill!!!!!