2365-614 (Unit 304) - INSPECTION, TESTING AND INITIAL VERIFICATION
What is a statutory document? - LEGAL - H&S at Work Act, EAWR
What is a non statutory document? - Not Legal - BS7671, On-Site Guide, Guidance Note 3,
GS 38
What equipment is used for safe isolation? - 1) approved Voltage indicator
2) proving unit
3) lock and key device
4) warning notices
5) relevant PPE
Process of Safe Isolation? - 1) identify means of isolation - determine what is to be worked
on
2) obtain permission to isolate
3) switch off
4) lock off
5) secure key - keep on person
6) select approved voltage indicator
7) test voltage indicator on known source (proving unit)
8) test between all conductors (3 test for single phase, 10 tests for 3 phase)
9) re-test voltage indicator
Explain all supply systems - TN-S:
Cable sheath earth (usually 2 core SWA). Zs path is via the cable sheathing. Max Ze = 0.8
ohm
TN-C-S:
