Today Megger has become synonymous with insulation test equipment that works using high voltage with low current across any two conductors to be sure that they are insulated properly. These instruments are manufactured by the Megger Group Limited, a company manufacturing measuring instruments and electrical test equipment for electrical power applications since 1889 but its trademark Megger Meter became popular in 1903.
On the whole, the testing performed using Megger meter is non destructive. To perform insulation test to check for any injured insulation which can cause short circuit when the device is under power, a voltage (DC) is applied to wire or the device under test and the results are analyzed to check for any leaks.
It is important to apply proper voltage while testing so that your device doesn’t get damaged. There are usually three ranges of voltage available for applications which are 300V, 750V, and 1000V. You must choose the correct voltage range of your Megger test equipment keeping in mind the working voltages of your device, i.e. you could use 300 volt range for a 240 volts device and 750 volt range for a 600 volt device, and for any voltage above 600 volt use the 1000 volts range. You may damage the device if you don’t follow the instruction manual of the Megger meter.