IEC 62067-2011 pdf free

IEC 62067-2011 pdf free.Power cables with extruded insulation and their accessories for rated voltages above 150 kV(Um = 170 kV) up to 500 kV(Um = 550 kV)-Test methods and requirements.
4.1 Rated voltages
In this standard, the symbols uo, U and Um are used to designate the rated voltages of cablesand accessories where these symbols have the meanings given in lEC 60183.
4.2Cable insulating materials
This standard applies to cables insulated with the materials listed in Table 1. It also specifies,for cables with each type of insulating compound, the maximum operating conductortemperatures on which the specified test conditions are based.
4.3 Cable metal screens/sheaths
This standard applies to the various designs in use. It covers designs providing a radial watertightness and other designs.
Designs that provide radial watertightness mainly consist of
metal sheaths,
longitudinally applied metal tapes or foils bonded to the oversheath,
composite screens, involving a bunch of wires and, in addition, either a metal sheath or ametal tape or foil bonded to the oversheath， acting as a radial water impermeable barrier(see Clause 5)
and other designs such as
bunch of metal wires only.
NOTE In all cases the metal screen/sheath should be able to carry the total fault current.4.4 Cable oversheathing materials
Tests are specified for four types of oversheath, as follows:- ST1and ST2 based on polyvinyl chloride (PVC);
-ST3 and ST┐ based on polyethylene (PE).
The choice of the type of oversheath will depend on the design of the cable and the mechanicaland thermal and fire constraints during operation.
The maximum conductor temperatures in normal operation for different types of oversheathingmaterials covered by this standard are given in Table 2.
NOTE For some applications, the oversheath may be covered by a functional layer (e.g.semi-conductive).
5Precautions against water penetration in cables
When cable systems are installed in the ground, in easily flooded galleries or in water,a radialwater impermeable barrier around the cable is recommended.
NOTE A test for radial water penetration is not currently available.
Longitudinal water barriers may also be applied in order to avoid the need to replace longsections of cable in case of damage in the presence of water.
A test for longitudinal water penetration is given in 12.5.14.IEC 62067 pdf download.