Whether it involves the connection cables the sectioning and protection equipment or the motors and generators the electrical conductors are insulated using materials with high electrical resistance in order to limit as much as possible the flow of current outside.
Cable insulation resistance test standard iec.
Test results are dependent on the temperature of the insulating material and the humidity of the surrounding environment at the time of the test.
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.
Z 2 electrical insulation testing.
Insulation resistance testing guide.
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.
960 15 c for parts containing live components 850 15 c for cavity wall parts 650 15 c for all others.
Insulation resistance decreases in temperature or moisture.
Ieee400 1 2007 ieee guide for field testing of laminated dielectric shielded power cable systems.
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.
S iec 60840 edition 4 0 2011 11 iec standards power cables with extruded insulation and their accessories for rated voltages above 30 kv um 36 kv up to 150 kv um 170 kv test methods and requirements câbles d énergie à isolation extrudée et leurs accessoires pour des tensions.
The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and.
Also acceptable values of insulation resistance depend upon the equipment you re testing.
Insulation resistance test data may be used to establish a trending pattern.
The equipment under test is brought into contact with the hot filament for 30 seconds.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
This type of test is a form of preventative maintenance.
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.
Table 100 22 minimum radii for power cable.
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.
The resistance is determined by the glow wire test.
The temperature amounts to.
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.
Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv.
