Before a 220 kV cable is put into service, a rigorous testing and commissioning program is conducted to confirm its integrity. This typically includes:

• Sheath Test (Outer and Inner): A DC voltage test is applied to the cable sheath to check for any damage that might allow moisture ingress.

• Partial Discharge (PD) Test: This is a crucial test for EHV cables. It detects small electrical discharges in voids or defects within the insulation or joints, which could lead to future failure. The test is performed with a very low frequency (VLF) or AC voltage.

• High-Voltage (Hi-Pot) Test: A high-voltage test is performed to verify the dielectric strength of the entire cable system, including all joints and terminations.

• Final Commissioning Report: A comprehensive report is prepared, documenting all test results and confirming the cable system is ready for service.