Testing of power cable
Testing of power cable is most important. power cable (High-voltage cables) are used for supplying power in densely-populated areas or for example to offshore installations. Trouble-free operation over decades with little or no maintenance is therefore a requirement to ensure a secure energy supply.
The cable can be tested non-destructively using dielectric diagnosis and partial discharge techniques. cable defect during the time of testing is considered a destructive test.
Low Voltage and High Voltage Cable Testing
- Phase Testing
- Screen wire test (Sheath Insulation Resistance test)
- Insulation Integrity Test
- Measuring the resistance of a fault
- Installation Testing
- measurements with a TDR(Time Domain Reflectometry)
- Continuity Test
- Insulation Resistance(MEGGER TEST)
- High voltage test
1. in aluminium conductor
- Tensile test
- wrapping test
2. Conductor resistance test
3. Annealing test
4. Persulphate test
5. Tensile strength for insulation and heath
- Water immersion test
- Flammability test
- Thickness of insulation test
- In low voltage system and high voltage system the correct phasing of circuits shall be checked at all positions.
- The LV cables are terminated into fuse bases and where any LV cable is run from one point to another point.
- The test may be conducted on either the wire screens or the aluminum conductors for 11 kv to 33 kv.
- Where the test is performed on the wire screens, they shall be disconnected from earth in case of HV circuits.
Screen wire test (Sheath Insulation Resistance test)
- The screen wire test is the most important test in combination with all diagnostic technologies.
- The test of the integrity of the outer sheath provides almost the ideal condition for the early detection of damages and provides the possibility of an early elimination of beginning cable faults.
- With a simple insulation and voltage breakdown test between cable shield and outer soil, it is already possible to conduct a commissioning test directly after laying and to confirm the integrity of the outer plastic sheath.
- For the testing of the cable sheath High voltage generators with an adjustable voltage of 0 to 5 respectivaly. 0 to 20 kV can be used. The commonly available insulation testers, which are sometimes recommended for this purpose by some local regulation are not usable for such a measurement.
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