Cable Insulation Resistance Test Procedure

General testing information for single conductor non shielded cable on a reel insulation resistance testing cannot be.

Cable insulation resistance test procedure.

This test is used to detect conductor insulation damage that may have been caused during installation. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. 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. Perform an insulation resistance test on each conductor with respect to ground and adjacent conductors.

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. Either turn off the breaker or if you re testing the wiring in a piece of equipment unplug it. Perform insulation resistance test on each conductor with respect to ground and adjacent conductors.

Insulation resistance decreases in temperature or moisture. Inspect cables and conductors for proper grounding cable support and termination. Inspect exposed sections of cables and conductors for physical damage. 7 3 2 2 2 2009.

Locate the connection point of the wire or cable you want to test so you have access to the exposed conductors. The insulation resistance test is the second test required by the electrical safety testing standards. What is insulation resistance testing. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs.

Insulation resistance testing is a non destructive test procedure. Applied potential shall be 500 volts dc for 300 volt rated cable and 1000 volts dc for 600 volt rated cable. Developed early in the 20th century the insulation resistance ir test is the oldest and most widely used test for assessing the quality of insulation. Replace or repair sections that exhibit damage.

Sample insulation resistance megohmeter test connections for cable and transformer using guard terminal. The insulation resistance of cable is measured using a megohmmeter. When performing insulation tests on conductors and cable apply the following procedure. Test duration shall be one minute.

The test measures the insu lation resistance between the phases and or between phase and ground. 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. 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. The insulation resistance test consists in measuring the insulation resistance of a device under test while phase and neutral are short circuited together.