Accurate, effective field testing and diagnostics of high-power cables
We provide a comprehensive suite of field tests for high power cables used in power stations and industrial and commercial facilities. Our teams are trained and equipped with the latest technologies for on-reel cable tests during installation and commissioning, and after maintenance and repair.
Typically, high power cables are tested when received, when installed, and during maintenance or repairs. Testing does more than identify potentially faulty cables. Testing—especially non-destructive testing—can identify existing weaknesses in cables, identifying potential faults before they cause cable breakdowns.
Destructive tests are categorized as “pass/fail” or “go/no-go” tests. By nature, a withstand test that tries to break down a cable defect during testing is considered a destructive test. Destructive tests typically consist of applying a high electric stress for a prescribed duration—commonly with DC, power frequency AC, and VLF AC voltages. It is important to recognize that field tests may trigger failure mechanisms within a cable that will not show up during the test but may cause subsequent failures in service.
Non-Destructive field tests are categorized as “diagnostic” tests which indicate the relative condition of the insulation system by comparison with figures of merit. Diagnostic testing is typically performed by means of moderately increased voltages for relatively short duration, or by means of low voltages. Two common diagnostic tests are PD testing and Dissipation Factor/Tan Delta testing. It is important to recognize that, in an advanced condition of insulation degradation, field tests may aggravate the condition of the cable and cause breakdown before the results can be determined or before the test can be terminated
Cable tests include
Hi Potential testing including DC, AC and VLF tests
Partial Discharge (PD) testing
Time Domain Reflectometry
Dissipation Factor/Tan Delta AC testing
Megger insulation resistance and dissipation tests
Cable fault location testing