Cable Insulation Test Using Megger

Applied potential shall be 500 volts dc for 300 volt rated cable and 1000 volts dc.

Cable insulation test using megger.

The test measures the insu lation resistance between the phases and or between phase and ground. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. The megger insulation tester is essentially a high range resistance meter ohmmeter with a built in direct current generator. The megger insulation tester is essentially a high range resistance meter.

Use megger on high resistance measurements only such as insulation measurements or to check two separate conductors on a cable. Cable testing and diagnostics provides information about the cable s global condition e g. A megger sends voltage through a cable and measures any current leakage in megohms 1 000 ohms. Insulation resistance testing is a non destructive test procedure.

For good insulation the resistance usually reads in the megohm range. Routine megger tests of aged electrical cable is a prudent way to ensure your circuits are safe from arc faults that can cause circuits to be blown and safe. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. Cable testing and diagnostics.

The insulation condition from values that are only relative. For cables above 300 volt to 600 volt use 1000 volt megger. Insulation resistance testing purpose. It s also known as an insulation tester.

For cables 300 volt use 500 vdc megger. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. De energize and discharge the circuit completely before connecting a megger. Never touch the test leads while the handle is being cranked.

The cable s overall insulation system and will reveal localised problems such as poor joints and terminations. A megger is an ohmmeter that measures resistance in the megohm scale. For cables above and less than 1200 volt use 2500 volt megger. For good insulation the resistance usually reads in the megohm range.

It will also reveal localised weak spots in the insulation. Perform insulation resistance test on each conductor with respect to ground and adjacent conductors. Testing electrical cable with a megohmmeter helps identify damage in the cable insulation.