Megger Testing Procedure
The Megger testing procedure is used by the electricians and handymen to test the insulation quality and electricity flow in high voltage electrical and electronic circuits. Common people think the Megger test is something that can be done only by proficient electricians. In reality, any high school kid can use the Megohmmeter efficiently to check whether the day to day electric items they use are safe enough to meddle with.
Basics of Megger Testing Procedure
Connecting the insulation part and conductor to the test leads in the Megger is the basic way to check whether the item is working properly. Imagine you want to check the insulation and current flow in a copper wire attached to some electronic device. You have to connect the inner copper wire or the conductor to one test lead and the insulation wire covering it to the other test lead in the Megohmmeter.
If you are checking the spark plugs in the vehicle, simply connect the negative end of the Megohmmeter to the spark plugs wire connected to the ignition coil. Connect the wire from the other end to the positive side of the device. Secure the wire to the leads through an electrical tape.
The test actually starts after this. Spin the crank in the megger to activate the DC generator in the device. The test leads are powered and a connection is established between the insulation lead and the conductor lead. The electricity voltage flowing in the leads are displayed in the meter readings.
Interpreting the Megger Test
Interpreting the results in the Megohmmeter is quite easy. The meter should display readings in between 1 to 2 mega ohms. 1 mega ohm is equivalent to 1000 volts. So, if you are testing the wires of a motor with 2000 volts capacity the reading should show 2 mega ohms. Anything less than or more than that indicates, there is very high resistance or very high current flow respectively. The cable should be changed if there is very high resistance.
Safety Measures in Megger Testing Procedure
Before trying anything, you must first know and be cautious about the following safety measures:
- The test leads should not be touched, as very high electricity will pass through them during the process.
- If possible, disconnect the cables you are testing from the concerned motor or any device they are attached to. Else, just make sure the device is properly powered off before you start Megger testing procedure.
- If you are testing the spark plugs in the vehicles, make sure you use safety gloves.
Megger testing can be conducted by any person on simple devices to see if there is short circuit. Learning the basics of electronics will help you do small emergency repairs in the house. With electricians and handy men appointments becoming as hard as a Mayor’s appointment, a good Megohmmeter can save both your time a lot.