Short Circuit Test

Short Circuit Test Points : Short Circuit Test The short circuit test should be made before the fans and lamps are installed; the test should he made with the fuses are inserted in distribution fuse board, all, switches ON, all lamps removed, all fans removed, all portable current carrying apparatus disconnected and the main switch closed. The megger is used for this test. The megger is connected either between phase and neutral leads.

Where two-way switches are installed in lighting circuits, two readings should be taken-one with both switches in one -‘ON’ position and another with both switches in the alternative ‘ON position.

Turn the megger handle and note the reading, if the megger shows the zero ohms or give a reading less than O.5MΩ, then steps must be taken to trace and rectify the fault. If the megger give the reading above O.5M, then this condition is satisfied and there is no short circuit in installation. If a sufficiently high reading be obtained on the whole wiring system then the distribution should be removed and the individual Circuits tested.

After a section has been proved to be faulty and before an attempt is made to remove any of the wiring part, it is advisable to test all switches, ceiling roses, lamp holders and connecting flexible, because such is the excellence of the insulating coverings on present-day.