Discharge in mV cables

Corona discharge is the most devastating aspect of a high (medium) voltage cable failure.

There are many reasons why corona discharge happens, but one of the main reasons is because of poor workmanship. 

• A nick or mark on the XLPE or EPR insulation on a cable will trap air and this combination with high voltage will ionise that air and the corona discharge will cause the cable to fail.

• A knife mark cut into the XLPE or EPR insulation creates a void which is difficult to fill.

Using knives in preparation of cables for jointing and/or termination in Australia is becoming a thing from the past, with scoring tools on the market which are used more in the workplace allowing for less chances of nicking or cutting the installation whilst removing the semi conductive layer.

Always remember when removing easy strip semi conductive layers, do not leave any nicks, cuts, or marks in the insulation as this will cause Partial Discharge (PD).

Current Training Services and Current Training Services Consultancy. 

Contact Stephen Harrison for more details on stephen@currenttrainingservices.com.au