PD component testing
PD component testing
(OP)
I am performing PD testing on short sections of sheath 22kV cable which has been factory tested to have <10pC at 22kV but I get very high PD readings 300-1000pC at 8.2kVwhich then decreases after several minutes to 2-3pC - does anyone know what effect is causing the decrease of the PD activity?
PD sometimes decreases prior to failure but this is new cable and the effect is repeatable by taking the cable to 9.2kV beyond inception then reducing and holding at 8.2kV
PD sometimes decreases prior to failure but this is new cable and the effect is repeatable by taking the cable to 9.2kV beyond inception then reducing and holding at 8.2kV






RE: PD component testing
Somethin terrible is stalking between the high voltage potentials
RE: PD component testing
I was using a HIPOTRONICS DDX9101 unit hooked to a XLPE cable 12,20,(22)kV.
RE: PD component testing
Somethin terrible is stalking between the high voltage potentials
RE: PD component testing
RE: PD component testing
Are you testing between the conductor and the screen, or is the screen floating?
Have you terminated the ends properly to be PD free? (I ask this because being a 1m length, the terminations would probably cover most of the length of cable, and you would be left with very little length of insulation where there is a screen over it - it would almost end up like an unscreened cable. If the ends have not been terminated properly, you would end up with problems.
If you have terminated properly, don't forget that you are now also testing the terminations and the cable, which is different to the factory, who may well have used a water termination. Chances are that the cable is fine.
Finally, why are you PD testing a 1m sample before it goes in the ground? This is a little over the top, unless you are suspicious about something happening during transport.
Ausphil
RE: PD component testing
RE: PD component testing
Something terrible is stalking between the high voltage potentials
RE: PD component testing