TEST

Tests
Verification Of Polarity

Check that all single-pole switches, thermostats, and other control devices are in the live side.

The polarity test is also made to ensure that the outer contacts of centre-contact byonet and Edison-type srew lamp-holders are connected to the neutral and that wiring has been correctly connected to plugs and socket-outlets.

Crossed polarity, sometimes termed 'Switched Neutral', is one of the major causes of severe electrical accidents.

Loop Impedance Test

Line-earth and Neutral-earth Loops.

Aim: To ensure that the loop impedance is low enough to ensure and allow sufficient current, in the event of an earth fault, to operate the protective device.

Earth-continuity Conductor

Earth Continuity test on the Continuity Conductor of AC installations.

After allowance has been made for the resistance of the leads, the value V/I when measured b/w two furtherest points of the installation is not to exceed  1 ohm (one ohm) This value is subject to loop impedance measurement which may require lower continuity values.

Earth-Leakage Circuit-Breaker

To test and make sure that it will trip effectively in the event of an earth fault.

Earth-Electrode Resistance

Due to an insufficiently - low earth loop impedance, it may be necessary to check  the actual resistance of the earth electrode to earth.

The electrode is disconnected from all sources of supply other than that used for testing.  It should be realised that the resistance of an electrode to the general mass of the earth depends upon the following:

a) shape and material of electrode
b) dept of soil in which buried
c) resistivity of surrounding soil which may be seasonal and in turn dependent upon moisture content.

Insulation Test

A Poor insulator has a comparatively low insulation value  and vice versa

Certificates

After the tecting and inspection of work done,  a completion and inspection certificate is issued. Periodic testing and inspection is important and must be stressed.