Cable Insulation Resistance Test Procedure

It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs.

Cable insulation resistance test procedure.

Test period must be for 1 minute using a voltage according to manufacturer s published data. 7 3 2 2 2 2009. General testing information for single conductor non shielded cable on a reel insulation resistance testing cannot be. A cable insulation test is basically a continuity test so the power to the circuit must be off.

Let s clarify our use of the term current. If no literature from the manufacturer is available apply 500 volts dc for 300 volt rated cable and 1000 volts dc for 600 volt rated cable. With a little record keeping and common sense however you can get a good picture of the insulation condition from values that are only relative. Replace or repair sections that exhibit damage.

Locate the connection point of the wire or cable you want to test so you have access to the exposed conductors. Either turn off the breaker or if you re testing the wiring in a piece of equipment unplug it. The insulation resistance of cable is measured using a megohmmeter. This test is used to detect conductor insulation damage that may have been caused during installation.

Inspect exposed sections of cables and conductors for physical damage. Insulation resistance testing is a non destructive test procedure. Perform insulation resistance test on each conductor with respect to ground and adjacent conductors. The insulation resistance test is the second test required by the electrical safety testing standards.

Sample insulation resistance megohmeter test connections for cable and transformer using guard terminal. The insulation resistance test consists in measuring the insulation resistance of a device under test while phase and neutral are short circuited together. The test measures the insu lation resistance between the phases and or between phase and ground. Basically you re applying a voltage specifically a highly regulated stabilized dc voltage across a dielectric measuring the amount of current flowing through that dielectric and then calculating using ohm s law a resistance measurement.

Test duration shall be one minute. When performing insulation tests on conductors and cable apply the following procedure. Applied potential shall be 500 volts dc for 300 volt rated cable and 1000 volts dc for 600 volt rated cable. Perform an insulation resistance test on each conductor with respect to ground and adjacent conductors.

What is insulation resistance testing. Inspect cables and conductors for proper grounding cable support and termination. An insulation resistance test is typically performed on de energized wire and cable immediately after installation and before termination to any equipment or accessories. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.