A Periodic Inspection and Testing is an inspection on the condition of an electrical
installation, to identify any deficiencies against the national safety standard
for electrical installations.
We work in accordance to IEE Wiring 17th Edition Regulations of British standard
BS7671, The NICEIC Code of Practice and hence we implement the testing sequence
procedure as defined by these standards, which shall be:
For a new fixed wiring electrical instatallation we first perform the following tests
- Continuity of protective conductors
- Main and supplementary bonding continuity
- Continuity of ring final circuit conductors
- Insulation resistance
- Site applied insulation
- Protection by separation
- Protection by barriers and enclosures
- Insulation of non-conducting floors and walls
- Polarity
- Earth electrode resistance if an earth electrode resistance tester is used
For a new fixed wiring electrical installation after fitting the supply we carry out the following:
- Earth electrode resistance if an earth-fault loop tester or the ammeter and voltmeter method are used
- Confirm correct polarity
- Earth-fault loop impedance
- Correct operation of residual current devices
- Correct operation of switches and isolators
Inspection and testing of existing installations
The sequence of periodic tests differs slightly from that for initial tests shown
above because in this case the supply will always be connected before testing starts.
There will be cases where necessary information in the form of charts, diagrams,
tables, etc., is not available. We will then need to investigate the installation
more thoroughly to make sure that we are fully conversant with it before we can
carry out his work.
Verfication of earth fault loop impedance values (Zs)