2391-51: Scenario 106

State the documentation to be issued to the client on completion of the electrical installation. q721

State who is responsible for determining the date of the first periodic inspection. q722

State two factors which may need to be considered when determining the date of the first periodic inspection. q723

State one statutory document and one non-statutory document which relate to the inspection and testing of an installation. q724

State two objectives of the initial verification process q725

State four items of essential information relating to the supply which are to be recorded on the certificate q726

State giving reasons, whether the copper cpc incorporated in the distribution cable is suitable as part of the main equipotential bonding to the gas and water services installed to the new building from the public supply. q727

Describe a suitable test to confirm the continuity of the cpc in a distribution cable. q728

Using the information contained in the second table, calculate the expected value for the test described in the previous question. Show all calculations, State why Zs, when measured at the new distribution board, may be different from the calculated value. q729

The continuity of ring final circuits is to be carried out before the installation is energised. Describe with the aid of sketches, the test for Circuit 1, giving the expected values for each stage of the test. Show all calculations. q730

An insulation resistance test is to be carried out on a new installation.

State what precautions need to be taken with regard to connected electrical equipment, in order to fully test the installation. q731

State the factors which will affect the total value at the distribution board for a new installation when measured. q732

State the test voltage to be applied, the minimum acceptable value as given in BS 7671 and any additional requirements from Guidance Note 3. q733

Calculate the expected overall value for the new installation if the test values for each of the individual circuits prior to connection to the distribution board was 200MΩ, show all calculations. q734

An earth fault loop impedance test for Circuit 10, General Lights Left, is to be carried out.

Calculate the expected value that will be obtained, using the information provided q735

Determine whether the value obtained in the previous question is acceptable and show all calculations q736

Describe the procedure for carrying out a direct measurement test. q737

Describe, with the aid of a fully labelled diagram, the earth fault path for Circuit 7. q738

Calculate the prospective earth fault current at the origin of the installation. q739

State, giving reasons, whether the prospective earth fault current at the new distribution board will be higher or lower than that at the origin. q740

State the importance of the prospective fault current in relation to the installed protective devices. q741