High Voltage test for Power Cable
High Voltage Test Guide for Power Cables
A complete high voltage test guide for power cable is essential for both of cable users and contractors to get clear idea about cable pre-commissioning and commissioning. Underground power cables should be tested before on-site commissioning or re-commissioning is known as SAT or Site-Acceptance-Test. Although cables are tested by the manufacturer in their factory is known as FAT or Factory-Acceptance-Test before delivery. FAT ensured the quality and specifications of the cables that followed as per international standard (like IEC, IEEE, BS) and customer’s requirements; on the other hand SAT is limited in that it gives no information about the quality of the circuit. The summary of this test results is simple just PASS or FAIL information; but this test gives the user a very degree of confidence that when they switch on to energize the line will operate satisfactorily.
Cable testing at site gives the satisfaction that during laying and carrying there happened no damage. So, cable testing including joints, terminations and all others accessories in site before switch on the power is mandatory for line construction companies and operators. Cable should be tested as per national or international specified specifications where applied voltage level and duration mentioned.
If at the end of the test time the circuit has withstood the applied voltage, then it gives the satisfactory result PASS; otherwise FAIL.
Getting Ready to Start High Voltage Test:
Consider the following points before start the Hi-Pot or High Voltage test performed.
Procedure to apply voltage:
Voltage may apply Continuous method or step method as per specification.
Caution: Don’t forget, DC charges on cable can build up to potentially dangerous levels if grounds are removed too quickly. Maintain solid grounds after the test on the cable for at least 4 times the duration of the test.