A megger is a type of megohmmeter used for testing electrical insulation in industrial settings. Although a conventional ohmmeter can perform well in most commercial settings, it is incapable of handling the high-voltage capacity of the megger. This is due to the fact that meggers can supply the voltage required to test the large conductors necessary for high-voltage circuits. While megging a circuit is quite easy, the safety issues at hand must be properly addressed, as any major mistakes could result in electrocution.
Things You'll Need
- Electrical wires
- Yellow caution tape
- Flat-head screwdriver
Cut off power to the circuit to be tested by flipping the breaker and locking it off with a padlock.
Surround the work area with yellow warning tape to protect anyone from accidentally touching the bare end of the cable.
Touch one megger probe to the bare end of the cable, then touch the other probe to the grounding screw of the system in which the cable will terminate.
Turn the megger handle manually and look for a rendering between 2 and 1,000 megohms. Insulation issues are indicated by any reading that is below 2 megohms.
Terminate the bare wire into its intended device using a flat-head screwdriver. Remove the yellow warning tape and the padlock. Restore the power to the circuit.
- "Electrician's Pocket Manual" (Pocket References, McGraw-Hill); Rex Miller; 2005
- Photo Credit bio battery image by dinostock from Fotolia.com
What is a Megger Tester?
Megger testers are devices that are used in order to test out electrical wiring as well as other components of buildings, government...
How to Use Megger Test Equipment
With a brand name that has been around for 120 years and test equipment so reliable that 50-year-old individual testers are still...
How to Use a Megohmmeter
The megohmmeter, or megger, is a measuring device that tests high electrical resistances. Typically these measurements are made on electrical wires and...
How to Use a Megger Insulation Tester
A Megger insulation resistance tester is especially useful when you have carried out electrical work on your home and want to make...
How to Know If Your Battery Cables Are Bad
Many car owners have had problems starting their car with what appears to be a dead or weak battery, only to have...
How to Megger a Transformer
Insulation tests rest primarily on the overall condition of the electrical equipment used to conduct the test. Dust, grime, humidity, oil, corrosion,...
How to Test Cable With a Megger
The megohmmeter, also known as a "megger," reads high voltage resistance measures in electrical circuits and motors. It is more commonly used...