Reference no: EM132349621

Electrical Installations: Inspection, Testing and Commissioning

Aim: The unit is designed to enable learners to understand how to carry out inspection and testing of complex electrical systems safely and in accordance with regulatory requirements. Learners will also develop the skills to apply their understanding in simulated environments

Learning outcome

1. Understand the requirements for completing the safe isolation of electrical circuits and installations

1. state the requirements of the Electricity at Work Regulations for the safe inspection of electrical systems and equipment

2. specify the appropriate procedure for completing safe isolation

3. state the reasons for carrying out safe isolation

4. state the implications of carrying out safe isolation

5. state the implications of not carrying out safe isolation

6. identify the Health and Safety requirements which apply when inspecting, testing and commissioning electrical installations and circuits

2. Understand the requirements for initial verification of electrical installations

1. state the purpose of the Initial Verification of electrical installations

2. state the requirements of the initial verification

3. identify the relevant documents associated with the inspection, testing and commissioning of an electrical installation

4. specify the information that is required by the inspector to conduct the initial verification of an electrical installation

3. Understand the requirements for completing the inspection of electrical installations prior to their being placed into service

1. select appropriate items to be checked during the inspection process

2. identify human senses appropriate for initial verification

3. state how the senses can be used during the inspection process

4. specify the requirements for the inspection of electrical installations

5. specify the requirements for the inspection to include:

a. special installations and locations as identified in Part 7 of BS 7671

b. IP Classification of equipment.

4. Understand the requirements for the safe testing and commissioning of electrical installations

1. state the tests to be carried out on an electrical installation in accordance with the BS 7671 and IET Guidance Note 3

2. identify the appropriate instrument for each test to be carried out in terms of:

a. The instrument is fit for purpose

b. Identifying the correct scale or setting.

3. specify the requirements for the safe use of instruments to be used for testing and commissioning, to include:

a. Checks required to prove that test instruments are safe and functioning correctly

b. The requirements for test leads and probes must comply with HSE Guidance GS38

c. The need for instruments to be regularly checked and calibrated.

4. explain why it is necessary for test results to comply with standard values

5. state the actions to be taken in the event of unsatisfactory results being obtained

6. explain why testing is carried out in the sequence specified in BS 7671 and IET Guidance Note 3

5. Understand the requirements for testing before circuits are energised

1. state why it is necessary to verify continuity to include:

a. Protective bonding conductors

b. Circuit protective conductors

c. Ring final circuit conductors.

2. state the methods for verifying continuity to include:

a. Protective conductors

b. Ring final circuit conductors.

3. explain factors that affect conductor resistance values

4. specify the procedures for completing insulation resistance testing

5. state the effects on insulation resistance values that the following can have:

a. cables connected in parallel

b. variations in cable length.

6. explain why it is necessary to verify polarity

7. state the procedures for verifying polarity

6. Understand the requirements for testing energised installations

1. state the procedures for confirming polarity of the incoming supply

2. specify the methods for measuring earth electrode resistance to include:

a. installations forming part of a TT system

b. generators and transformers.

3. describe common earth fault loop paths

4. state the methods for verifying protection by automatic disconnection of supply

5. identify the requirements for the measurement of prospective fault current

6. specify the methods for determining prospective fault current

7. verify the suitability of protective devices for prospective fault currents

8. specify the methods for testing the correct operation of residual current devices

9. state the reasons for verifying phase sequence

10. state the methods used to verify phase sequence

11. state the need for functional testing

12. identify items which require functional testing

13. state the appropriate procedures for dealing with clients during the commissioning and certification process

7. Understand the requirements for the completion of electrical installation certificates and associated documentation

1. explain the purpose of certification and associated documentation

2. state the information that must be contained on initial verification documentation

3. describe the certification process for a completed installation

4. identify the responsibilities of different relevant personnel in relation to the completion of the certification process

5. explain the requirements for the recording and retention of completed initial verification documentation in accordance with the BS 7671

8. Be able to confirm safety of system and equipment prior to completion of inspection, testing and commissioning

1. carry out safe isolation procedures in accordance with regulatory requirements

2. comply with the Health and Safety requirements of themselves and others within the work location during the initial verifications process

3. check the safety of electrical systems prior to the commencement of inspection, testing and commissioning

9. Be able to carry out inspection of electrical installations prior to them being placed into service

1. identify a safe system of work appropriate to the work activity

2. carry out an initial inspection of an electrical installation in accordance with the requirements of BS 7671 and IET Guidance Note 3

3. complete a Schedule of Inspections in accordance with BS 7671 and IET Guidance Note 3 based on engineering evaluation of the installation to be verified

10. Be able to test electrical installations prior to them being placed into service

1. select the test instruments and their accessories for tests to include:

a. continuity

b. insulation resistance

c. polarity

d. earth electrode resistance

e. earth fault loop impedance

f. prospective fault current

g. RCD operation

h. phase sequence

i. functional testing.

2. evaluate the appropriate tests suitable for the installation to be verified

3. carry out tests in accordance with BS 7671, IET On-site Guide and Guidance notes 3 to include:

a. continuity including:

i. main protective bonding conductors

ii. circuit protective conductors

iii. Ring Final Circuits.

b. insulation resistance

c. polarity

d. external earth fault loop impedance (Ze)

e. system earth fault loop impedance (Zs)

f. prospective fault current

g. RCD operation including additional protection

h. phase sequence

i. functional testing.

4. confirm compliance by evaluating and verifying test results

5. complete appropriate documentation in accordance with the BS 7671 and IET Guidance Note 3 including:

a. Electrical Installation Certificate

b. Schedule of Inspections

c. Schedule of Test results.

11. Be able to commission electrical systems and equipment

1. clarify the commissioning procedures with relevant persons

2. carry out the commissioning of circuits, accessories and equipment to confirm functionality