APPLICATION Of VDE Standard 33kv power cable xlpe single core
VDE Standard 33kv power cable single core are designed for distribution of electrical power with nominal voltage Uo/U ranging from 3.8/6.6KV to 19/33KV and frequency 50Hz. They are suitable for installation mostly in power supply stations, indoors and in cable ducts, outdoors, underground and in water as well as for installation on cable trays for industries, switchboards and power stations.
STANDARD Of VDE Standard 33kv power cable xlpe single core
DIN VDE 0276 Part 620 -622
HD 620 S1
CONSTRUCTION Of VDE Standard 33kv power cable xlpe single core
Conductor: Stranded compacted circular copper or aluminum conductors according to IEC 60228 class 2 / VDE 0276 class 2 / VDE 0295 HD 383. All internal interstices of the conductor are filled with water blocking compound to prevent ingress of water through conductor during storage, handing, installation and operation of the cable.
Conductor Screen: The conductor screen consists of an extruded layer of non metallic, semi-conducting compound firmly bonded to the insulation to exclude all air voids. The screen has a minimum thickness of 0.3mm and the maximum volume resistivity of 500 Ohm-m at 90°C.
Insulation: Insulation is of extruded XLPE compound type 2XI1 according to DIN VDE 0207 part 22 and HD 620.1 with high degree of cross-linking, free from contaminants, air voids and heat resistant by dry cured process. The nominal insulation wall thickness is shown in table 1.
Table 1. Insulation Thickness
|
Nom. Cross |
Insulation Thickness at Nom. Voltage |
||||
|
Section Area |
3.6/6KV (Um=7.2kV) |
6/10Kv (Um=12kV) |
8.7/15kV (Um=17.5kV) |
12/20kV (Um=24kV) |
18/30kv (Um=36kV) |
|
mm² |
mm |
mm |
mm |
mm |
mm |
|
35 |
2.5 |
3.4 |
4.5 |
5.5 |
- |
|
50 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
70 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
95 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
120 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
150 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
185 |
2.5 |
3.4 |
4.5 |
5.5 |
8 |
|
240 |
2.6 |
3.4 |
4.5 |
5.5 |
8 |
|
300 |
2.8 |
3.4 |
4.5 |
5.5 |
8 |
|
400 |
3 |
3.4 |
4.5 |
5.5 |
8 |
Insulation Screen: The insulation screen consists of extruded non metallic, semi-conducting compound extruded over the insulation. The extruded semi-conducting layer shall consist of bonded or cold strippable semi-conducting compound capable of removal for jointing or terminating. The minimum thickness is 0.3mm and the maximum volume resistivity of 500 Ohm-m at 90°C. The screen is tightly fitted to the insulation to exclude all air voids and can be easily hand stripped on site.
Conducting Water Blocking Layer: The insulation screen may be covered by semi- conductive water blocking tape which will swell up under the influence of moisture of water to ensure longitudinal watertightness.
Metallic Screen: Copper wires are applied over the conducting water blocking layer with a minimum diameter of 0.5mm. And over the copper wires, copper tape with minimum thickness of 0.1mm is applied helically with overlap. Total cross section of metallic screen layer is shown in table 2. The screen can withstand fault current to earth of 1000 A for one second at maximum temperature of 160°C. Minimum cross section of concentric conductor is according to DIN VDE 0273 & 0276 as shown.
Table 2. Minimum Total Cross Section of Metallic Screen
|
Nominal Cross-Section Area |
Minimum Cross-Section |
DC Resistance of the Copper Wire Screen |
|
Of Cable |
of Metallic Screen |
|
|
mm² |
mm² |
mm |
|
Up to 120 |
16 |
1.06 |
|
150-300 |
25 |
0.72 |
|
400-630 |
35 |
0.51 |
|
800-1000 |
50 |
0.35 |
Separator/Water Blocking Layer: The metallic screen may be covered by non-conducting water blocking tape which will swell up under the influence of moisture of water to ensure longitudinal watertightness. Separation Sheath (for armored cable): The separation sheath comprises a layer of extruded PVC,PE or LSZH, applied under the armor. Thickness of separation sheath as shown in table 3.
Table 3. Separation Sheath Thickness
|
Core Diameter |
Approx. Thickness of Inner Sheath |
|
|
mm |
mm |
|
|
> |
< |
|
|
35 |
45 |
1.4 |
|
45 |
60 |
1.6 |
|
60 |
80 |
1.8 |
|
80 |
- |
2 |
Armour(for armored cable): The armor consists of round aluminum wire armor applied helically over an extruded separation sheath.
Table 4. Round Armour Wire Diameter
|
Fictitious Diameter Under the Armour |
Armour Wire Diameter |
|
|
mm |
mm |
|
|
> |
< |
|
|
- |
10 |
0.8 |
|
10 |
15 |
1.25 |
|
15 |
25 |
1.6 |
|
25 |
35 |
2 |
|
35 |
60 |
2.5 |
|
60 |
- |
3.15 |
Outer Sheath: Overall sheath comprises a layer of extruded PR compound DMP2 according to HD620.1 and 2YM3 type to DIN VDE 0276 Part 3, or PVC compound DMV6 according to HD620.1 and YM5 to DIN VDE 0276 Part 6. Normal wall thickness is 2.5mm (1/500mm 18/30sq 2.6mm), suitable for exposure to sun-light or other local atmospheric environments and for the operating temperature of the cable.
Service Life: 30years
PHYSICAL PROPERTIES Of VDE Standard 33kv power cable xlpe single core
Operating Temperature: up to 90°C
Temperature Range: -5°C ( PVC sheath ); -20°C ( PE sheath )
Short Circuit Temperature: 250°C (short circuit duration up to 5 seconds)
Bending Radius: 15 x OD (Cable without metal sheath)
30 x OD (Cable with aluminum sheath)
Table 5. Nominal/Operating/Testing Voltages
|
Nominal Voltage Uo/U |
Operating Voltage (max) |
Testing Voltage |
|
3.6/6KV |
8KV |
10KV |
|
6/10KV |
12KV |
15KV |
|
8.7/15KV |
18KV |
22.5KV |
|
12/20KV |
24KV |
30KV |
|
18/30KV |
36KV |
45KV |
TYPE CODES Of VDE Standard 33kv power cable xlpe single core
Cores
N According to VDE Standard (No abbreviation for copper conductor)
A Aluminum Conductor
2X XLPE Insulation
Y PVC Insulation
Screen
S Screen of copper wires and copper tape, helically wound.
SE Screen of copper wire plus copper tape over each individual cores, helically wound
(F) Longitudinally waterproof screen.
Concentric Conductor Screen
C Concentric conductor screen of copper wires and copper tape, helically wound.
CE Concentric conductor screen of copper wire plus copper tape over each individual cores, helically wound.
Jacket
2Y PE Jacket
Y PVC Jacket
H LSZH Jacket
