How do you Megger an HT cable?
A 5kV Megger is suitable for a 5kV test on cables after repairs….HV test on new XLPE cable:
| Application | Test Voltage | Criteria |
|---|---|---|
| New cables – Sheath | 1kV Megger 1 minute | 100 meg-ohms min. |
| New cables – Insulation | 10kV DC 15 minute | 1.0 μA (micro-amps) max |
| New cables – Insulation | 10kV DC 15 minute | 1000 meg-ohms min. |
How do you test high voltage cables?
Perform an insulation-resistance test individually on each conductor with all other conductors and shields grounded. Apply voltage in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1. Perform a shield-continuity test on each power cable.
What is the minimum acceptable value of cable insulation resistance?
Insulation resistance should be approximately one megohm for each 1,000 volts of operating voltage, with a minimum value of one megohm.
How many types of cable testing are there?
Examples of type tests include: Corrosive and acid gas emissions testing. Mass of zinc coating for galvanised wire armour. Smoke density testing (the 3m cube test for LSZH cables) Flame propagation test for multiple cables.
Why is high insulation resistance preferred in cable?
In general, the insulating materials used in cables should have the following properties : High insulation resistance to avoid leakage current. High dielectric strength to avoid electrical breakdown of the cable. High mechanical strength to withstand the mechanical handling of cables.
What should be the minimum insulation resistance of a 11 kV line when tested with a 1000 V Megger?
Minimum insulation resistance of a 11 kV line when tested with a 1000 v Megger is 50 kV.
How do I know if my cable is healthy?
The following tests are type test of electrical power cable.
- Persulphate test (for copper)
- Annealing test (for copper)
- Tensile test (for Aluminium)
- Wrapping test (for Aluminium)
- Conductor resistance test (for all)
- Test for thickness of insulation (for all)
- Measurement of overall diameter (where specified) (for all)