Polarity
This test is carried out to ensure that:
· Polarity at the main supply point is correct.
· The phase conductor is connected to fuses, single pole circuit breakers and switches.
· Incoming supply is connected to back contact of screw in type fuses.
· The phase conductor is connected to the centre contact of ES type lampholders .
· All wiring is correctly connected at socket outlets and other similar accessories.
There is no particular test method specified in the ETCI Rules on how to conduct this test.
The continuity of the protective conductor has already been verified. This test can be completed in basically the same manner.
Ensure that all appliances, lamps etc are unplugged or otherwise removed. With the circuit MCB in the “off” position, connect one end of the long trailing lead to the outgoing terminal of the circuit MCB. Using the other end in conjunction with the test meter leads, take readings from the phase terminal of all the points around the circuit e.g. switches, luminaries, sockets etc. Continuity ( approx. resistance of conductor involved ) at each outlet ensures that polarity is correct.
If the supply is disconnected from the installation the long trailing lead may be connected to the phase busbar and the MCB should then be left in the “on” position.
Test of Polarity of Socket Circuits
