TYPICAL ROUTIN TESTS FOR HV XLPE OR EPR CABLES

Conductor examination : Number of wires / Diameter (in mm) maximum & minimum of measured values and requirements
- Conductor screen thickness measurement (in mm), maximum & minimum measured values and requirements
Insulation Resistance(IR) in Mega Ohm (or MW/average) ,
Wall thickness depends on rated voltage (U0) and insulation type according to IEC60502-2 (in mm) maximum & minimum measured values and requirements
Insulation screen (in mm): wall thickness (in mm) maximum & minimum measured values and requirements and diameter
Metal screen maximum & minimum measured values in mm and cross section in mm2.
- Hot set test defined in IEC 60811-507
- It is a mechanical-thermal test for polymetric insulation or sheath materials like XLPE, EPR, or PVC.
- A test piece of insulation (usually a strip) is cut.
  - A specified load (0.2MPa for insulation, 0.15MPa for sheath) is applied.
  - The sample is placed in an oven at 200°C (for XLPE) or specified temperature.
  - The elongation and permanent deformation (set) after cooling are measured.
  - The maximum elongation under load is measured.
- Pass criteria (typical for XLPE insulation):
- Elongation under load <= 175%
- Permanent elongation after cooling <= 15%

High voltage test – IEC 60840 , Edition 5
Partial discharge test (IEC/VDE) [kV]
Voltage test (IEC/VDE) : Kv / 30min
Electrical test on oversheath-DC test : kV / 1min
Measurement of conductor Resistance (Ohm/km , 20°C)
Measurement of screen Resistance (Ohm/km , 20°C)
- Measurement of Capacitance (‌mF/km)

Published by Amir Mostafavi