Testing of Megger Before Use

Testing of Megger Before Use Points : testing of megger before use Before use for different testing work of an installation, it is always imperative to test the accuracy of an insulation testing megger. Many important tests like insulation resistance test, short-circuit test, continuity test are carried out with the help of a megger. If there is defect in the working system of the instrument, accurate test results cannot be obtained. This may result in fatal accident or disaster at any time. Hence, before use, the handle of a megger is to be rotated at first keeping its two terminals open. The pointer must rest on ‘infinity’ mark of the scale at this time. Afterwards the two terminals of the instrument are joined together (short-circuited) with a small piece of wire and the handle is rotated as before. This time the pointer should rest on ‘Zero’ reading. If the results of these two tests are satisfactory, it may be assumed that the working system of the megger is in good condition and the instrument may be used for different testing work of an installation.