Step by step Commissioning guidelines of HV/ HT Cable
Check continuity of the HT cable to confirm R, Y and B phase at both ends as per marking. This is especially important when there is more than one run of cable phase; any cross-over will result in a dead short circuit.
The Cable screen is to be earthed at one end only.
Cable gland plate should be of non- magnetic type e.g. aluminum.
Perform HV / HT test on the cable.Apply only Dc voltage, as cables have relatively higher capacitance. Check IR values before and after HV test. The HV and megger tests are conducted between each phase and earth, with the other two phases earthed.
In case the cable lug is of aluminum and the busbar is of copper, bimetal washers are to be put between the plug and the bus bar, with the Al on the Al side and CU on the Cu side.
Ensure tightness of the cable termination at both ends.