Test results are dependent on the temperature of the insulating material and the humidity of the surrounding environment at the time of the test.
Cable insulation resistance test standard iec.
If the insulation resistance falls below an accepted user dictated value or falling rapidly over time then cable.
Also acceptable values of insulation resistance depend upon the equipment you re testing.
Z 2 electrical insulation testing.
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.
Insulation resistance testing guide.
Ieee400 1 2007 ieee guide for field testing of laminated dielectric shielded power cable systems.
The temperature amounts to.
Table 100 22 minimum radii for power cable.
Deviations from the baseline information permit evaluation of the insulation.
The equipment under test is brought into contact with the hot filament for 30 seconds.
Cables for rated voltages of 1 kv um 1 2 kv and 3 kv um 3 6 kv reference number iec 60502 1 2004 e international standard iec 60502 1 second edition 2004 04.
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.
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.
960 15 c for parts containing live components 850 15 c for cavity wall parts 650 15 c for all others.
The resistance is determined by the glow wire test.
This type of test is a form of preventative maintenance.
Insulation resistance decreases in temperature or moisture.
11 ieee 400 2012 omnibus ieee guide for field testing and evaluation of the insulation of shielded power cable systems rated 5 kv and above.
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.
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.
The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and.
