Insulation Resistance Test Standard For Cable

Cables for rated voltages of 1 kv um 1 2 kv and 3 kv um 3 6 kv reference number.

Insulation resistance test standard for cable.

The insulation resistance test is the second test required by the electrical safety testing standards. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. Table 100 22 minimum radii for power cable. The insulation resistance test consists in measuring the insulation resistance of a.

Principle of insulation testing and influencing factors insulation resistance measurement is based on ohm s law. Insulation resistance testing is a non destructive test procedure. If during periodical testing insulation resistance of cable is found between 5 and 1 mω km at buried temperature the subject cable should be programmed for replacement. 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.

Power cables with extruded insulation and their accessories for rated voltages from 1 kv um 1 2 kv up to 30 kv um 36 kv part 1. Also acceptable values of insulation resistance depend upon the equipment you re testing. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. Regular testing of the insulation on an installation or machine is therefore a useful way of monitoring this type of deterioration so you can act before total failure occurs.

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. Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv. Insulation resistance test data may be used to establish a trending pattern. After dc overpotential test is completed the insulation resistance test is done again to assure that the cable has not been damaged by the hi pot.

Minimum acceptable insulation resistance for 600 v cable from 100 to 1000 feet. Deviations from the baseline information permit evaluation of the insulation. If insulation resistance of the cable is found between 1000 and 100 kω km at buried temperature the subject cable should be replaced urgently within a year. The test measures the insu lation resistance between the phases and or between phase and ground.

The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and. Insulation resistance testing purpose. Insulation resistance decreases in temperature or moisture.