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 in industrial electrical installations than the ohmmeter because it is more accurate in detecting subtle anomalies in high voltage circuits. This is due in part because the megohmmeter produces higher voltages than the ohmmeter. Megging an electrical circuit is simple enough to do yourself, though you should be very careful to follow the safety procedures exactly as instructed.

Things You'll Need

  • Electrical wires
  • Red warning tape
  • Yellow caution tape
  • Flip the breaker off for the circuit you will be working on and tape the breaker shut with red warning tape. This ensures that no one will turn the breaker on while you are working on the circuit.

  • Apply yellow caution tape around the end of the circuit that you will be working on; then detach the other end of the circuit from the device it is intended to feed. You will be adding voltage to the circuit with the megger, so the yellow caution tape will keep people from getting too close to the exposed wire.

  • Place one megger lead to the exposed wire and the other lead to the system ground. This can be any metal surface that is touching the grounding bolt to which the green grounding cable is attached.

  • Crank the megger and read the meter. A reading between 2 and 1,000 megohms is acceptable; anything less than 2 megohms means that you have a problem with the insulation.

Related Searches


  • "Electrician's Pocket Manual": (Pocket References (McGraw-Hill)); Rex Miller; 2005
  • Photo Credit battery tester on white image by JoLin from
Promoted By Zergnet



You May Also Like

  • 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 Read a Megger

    In order to measure the insulation resistance in electrical wiring and electrical motors, electricians use the megohmmeter, also known as a megger....

  • 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 Use a Megger to Test a Circuit

    A megger is a type of megohmmeter used for testing electrical insulation in industrial settings. Although a conventional ohmmeter can perform well...

  • How to Test Megger Motors

    A Megger is the brand name of a special megohmmeter capable of detecting very small resistance disturbances in high-voltage electrical circuits. It...

  • How to Interpret Megohmmeter Readings

    Megohmmeters, or meggers, are testing meters used to measure the current leakage from an electrical cable by means of administering an insulation-resistance...

  • What Are the Standards for Megger Testing?

    Megger Group Limited is a manufacturer of electric test equipment and measuring instruments for electrical power applications. Although all of its products...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!