Electrical Installation: fault diagnosis and rectification

1. What is the most appropriate method to protect against electric shock when carrying out fault diagnosis work?

2. Why should a method statement be followed by an operative when undertaking work on an installation to diagnose a fault?

3. What voltages must GS38 equipment be used on?

4.Which document should be completed when replacing an existing faulty motor isolator switch?

5. Who must be kept informed of faults found on an installation during the fault finding process?

6. What type of fault is most likely to have occurred on an lighting circuit which has caused a protective device to operate when a light is switched on?

7. What is the most likely outcome of a fault between live conductors on a transformer feeding a light fitting?

8. What is the most likely outcome of a loose termination on the load side of an isolator, when the switch is operated?

9. What is the most likely direct cause of a fault involving insulation failure of a PVC cable?

10. What is most likely to be the fault if the final light on a circuit was not operating and the rest of the lights on the circuit were operating?

11. What fault should an operative be looking for following a report that all but one of the socket-outlets on a ring final circuit was working?

12. What precaution must an operative task, should they come across an electrical installation containing a photovoltaic array?

13. What is the most appropriate precaution to protect against damage to electronic equipment during the fault-finding process?

14. Which instrument is required to measure current flowing in a circuit, where it is impractical to break the line conductor?

15. Where does ‘identification of symptoms’ come in respect to the logical stages of fault diagnosis?

16. Which one of the following applies where an instrument is to be used for insulation resistance testing?

17. What is the maximum length of probes on test leads that comply with GS38?

18. Which method is used to ensure that a low resistance ohmmeter was ready for accurate measurements?

19. What is the most appropriate method to identify a fault on a RCD that operates repeatedly?

20. After repair of a faulty circuit, what should the expected earth fault loop impedance value be, where the line and cpc measured resistances are 1.21 Ω and 1.81 Ω respectively, and the Z_e was measured at 0.8 Ω?

21. What is the most likely reason for an extractor fan running too slowly?

22. What are the main factors that need to be considered when replacing a damaged single-phase distribution board in a commercial premises?

23. What is the most significant factor to consider when needing to replace a component on a production line that is in 24-hour operation?

24. Which of the following is the main consideration when carrying out fault diagnosis work in a large operational commercial kitchen?

25. What is the main consideration when undertaking fault diagnosis and rectification work on a six-month-old commercial installation?

26. What is verified by functional testing after fault rectification?

27. An insulation resistance test is to be carried out as part of the fault-finding process on a 230 V lighting circuit. What is the test voltage to be applied?

28. Which test instrument setting is required to check the sensitivity of an RCD?

29. After replacing a three-phase motor, which test is most appropriate when ensuring correct operation?

30. Which material comes under the requirements of the WEEE regulations when disposing of waste after corrective work?