CGLI 2330 Certificate in Electrotechnical Technology Level 3 Installation Technology: Unit 302/3 – Inspection & Testing and Fault Diagnosis & Rectification
Unit 12 – Testing
Testing Unit Aims By the end of the unit participants should be able to: describe the requirements of testing with reference to a) types of test equipment b) sequence and procedures for tests c) application of BS:7671 (Syllabus Reference: 2.2.10) describe how to carry out tests for a) continuity b) insulation resistance c) polarity d) earth fault loop impedance e) earth electrode resistance f) operation of RCD g) functional testing (Syllabus Reference: 2.2.07) explain the need to comply with test values and state the actions to take in the event of unsatisfactory results (Syllabus Reference: 2.2.08)
Testing Tests should be carried out in the following sequence: Before the supply is connected: i) Continuity of protective conductors, including main and supplementary bonding ii) Continuity of ring final circuit conductors, including protective conductors iii) Insulation resistance iv) Polarity (by continuity methods) v) Earth electrode resistance, when using an earth electrode resistance tester (see vii also) With supply connected: vi) Check polarity of supply, using an approved voltage indicator vii) Earth electrode resistance, using a loop impedance tester viii) Earth fault loop impedance ix) Prospective fault current measurement, if not determined by enquiry of the distributor x) Functional testing, including RCDs and switchgear. Suitable methods of testing are described in the ‘On-Site Guide’ Section 10. The use of other methods of testing is not precluded provided that they will give results that are no less effective. If a test indicates a failure to comply, that test, and the preceding tests (whose results may have been affected by the fault) must be repeated after rectification of the fault.
The College at Clacton
Unit 12 Page 1
December 2011