1016
Ohm cm
• Loss factor (tan (20°C) max.
The manufacture this sheath based high density
polyethylene (HDPE), which additive organic
peroxide mixed.
Semi-conducting type
– Over the outer semi-conducting layer, semi-
conducting tape must used.
Insulation
– Cross-linked polyethylene (XLPE), compound
type DIX8 according 620 S2.
– Semi-conducting compound, cross-linked,
wall-thickness 0,3 0,6 mm. 200%
• Tensile strength min.
In order prevent the penetration moisture and
also extend the duration life, the XLPE-insulated
medium voltage cables are designed with longitudinally
water-proof screen including additional swell tape
and outer sheath.
Moreover, better dielectric constant value has an
effect the low mutual capacitance, the short-circuit
to ground and the charging current XLPE-insulated
cables.Q
583
Since about 1970 the cross-linked polyethylene
(XLPE)-insulated power cables have been used in
Germany. taping).
Inner semi-conducting layer
– Semi-conducting compound, cross-linked,
mini-mum wall-thickness 0,3 mm.
– Copper cross-section according 620 S2.
The good properties XLPE-insulated cables remain
constant through wide temperature range. Due to
various advantages, the XLPE-insulated type has vastly
displaced the traditional classical paper-insulated types
in many sectors.
– Insulation nominal wall-thickness
for 6/10 3,4 mm
12/20 5,5 mm
18/30 8,0 mm
Outer semi-conducting layer
– Outer semi-conducting layer extruded together
with the inner semi-conducting layer and the
insulation one working process and are spliced
with each other. 12,5 N/mm2
Conductor
– Copper aluminium, round, multiwire stranded
and compact, according VDE 0295. This type insulation very
chemically resistant and also resistant cold.
Characteristics XLPE
• permissible operating temperature
– For permanent (normal) operation 90°C
– short circuit +250°C
– overload operation and
damage sea +130°C
• Specific heat resistance 3,5 m/W
• Dielectric constant 2,4
• Specific resistance (20°C) min.
In comparison PVC and paper-insulated cables, the
advantage XLPE-insulated medium voltage power
cables that they possess low dielectric factor, such as
it 100 times smaller than PVC-insulated cables. The XLPE-insulation possesses very good
electrical, mechanical and thermal characteristics in
medium voltage networks.
Screen
– Screening copper wires must have minimum
diameter 0,5 and over that copper tape
applied helically with minimum thickness of
0,1 mm.
Outer sheath
– compound DMP2 according 620 black or
– PVC compound DMV6 according 620 red
– Wall-thickness 2,5 mm,
for 500 mm2
/30 2,6 mm
Continuation
▲
MEDIUM VOLTAGE POWER CABLES
XLPE-insulated 6/10 kV, 12/20 kV, 18/30 kV
. 0,5 10–3
• Density 0,92 g/cm3
• Breaking strength min.
Separator
– Over the screen well under outer sheath,
a separating layer must used (e.
Concentricity conductor
– The difference between the maximum and
mini-mum value 0,5 should not be
exceeded. Due the heating and pressure the
molecule chains are joined each other, assuring the
transition from thermoplastic elastic condition
