Practical skills

The candidate will be able to:

1 select the correct instruments or functions and appropriate scales to carry out tests

2 check and prove instruments and leads for safety and function

3 carry out the Initial Verification (inspection, testing and certification) of an installation to BS7671

4 complete an Electrical Installation Certificate (as given in BS 7671 or Guidance Note 3), for the installation in item 3, including the Schedule of Test Results

5 carry out an inspection of installation components and complete the Schedule of Inspections.

Underpinning knowledge

For each topic below, the candidate will be able to:

Instruments

3.1 State the need for instruments to be regularly checked and the need for compliance with the requirements of BS 7671 (current edition) and HSE Guidance Note GS 38

3.2 List the correct instruments, functions and appropriate scale(s) to carry out each test and explain the reasons for each choice

Sequence

3.3 State the recommended sequence of tests covered by this unit and the reasons for that sequence

Protective Conductors

3.4 State the requirements which need to be considered for protective conductors in terms of

1. a) earthing conductors
2. b) main protective bonding conductors
3. c) supplementary equipotential bonding conductors
4. d) circuit protective conductors

3.5 Describe the need for, and methods of, verifying the continuity of protective conductors and the interpretation of results

3.6 State the relationship between conductor length, cross sectional area (csa) and resistance

3.7 State the effect of temperature on conductor resistance.

Ring Final Circuits

3.8 State the effect on conductor resistance when cables are connected in parallel

3.9 Describe the need for, and the method of verifying the continuity of, ring final circuit conductors and the interpretation of results

3.10 State the relationship between conductor length and conductor resistance.

30 Level 2 Certificate in Fundamental Inspection, Testing and Initial Verification (2392-10)

Insulation Resistance

3.11 Explain, by example, the effect on insulation resistance of

1. a) cables connected in parallel
2. b) variation in cable length

3.12 State the difference between measurements taken for insulation resistance and conductor resistance, and the order of magnitude that would be expected in each case

3.13 State the preconditions required for the performance of insulation resistance testing in terms of:

1. a) client consultation
2. b) safety procedures and notices

3.14 State the precautions to be taken before testing insulation resistance in terms of

1. a) isolation of circuits and equipment
2. b) voltage sensitive equipment
3. c) electronic components

3.15 Describe methods of testing insulation resistance

3.16 State the required test voltages and minimum values of insulation resistance for circuits operating at various voltages

SELV

3.17 Describe the test to verify separation between SELV circuits and other circuits.

Special Installations and locations

3.18 State the requirements for locations containing baths or showers in terms of

1. a) circuits
2. b) equipment
3. c) zones.

IP Code

3.19 State the appropriate degrees of protection required for given locations and environments

afforded within the IP classification BS EN 60529.

Polarity

3.20 State the reasons for tests to confirm correct polarity

3.21 Describe the methods of testing used to identify correct polarity

3.22 State the reasons for confirming correct polarity following initial energising of installations.

Earth Electrodes

3.23 State the instruments used for testing earth electrodes as

1. a) Earth electrode resistance tester
2. b) Earth fault loop impedance tester

3.24 Describe the method of testing earth electrode resistance using an earth fault loop impedance tester.

Earth Fault Loop Impedance

3.25 Describe the earth fault loop impedance paths for the following systems

1. a) TN-S
2. b) TN-C-S
3. c) TT

3.26 Describe methods of determining earth fault loop impedance in terms of

1. a) the tests used for measuring actual earth fault loop impedance
2. b) methods of calculation of earth fault loop impedance from given data and measurement of conductor impedance.

3.27 Given maximum tabulated values of earth fault loop impedance, verify that measured values are acceptable, taking into account conductor operating and ambient temperatures

Residual Current Devices (RCD)

3.28 Describe methods of testing the correct operation of an RCD, independent of in-built test facilities

3.29 State the applications for various RCD ratings

3.30 State the requirements for RCD in series.

Prospective Fault Current

3.31 Describe prospective fault current in terms of

a) prospective short-circuit current

b) prospective earth fault current

3.32 State methods of determining prospective fault current

3.33 Describe the methods of measuring prospective fault current

3.34 Explain the importance of confirming that protective devices are appropriate for the prospective fault current.

Verification of voltage drop

3.35 State the methods of evaluating voltage drop

3.36 Determine compliance with voltage drop from given criteria.