High Voltage and Extra High Voltage Cables
GUIDE TO THE SELECTION OF EHV AND HV CABLES
EHV and HV cables are specially designed on the basis of the project data. To determine
appropriate design of a high voltage cable for a particular project, the following minimum
information regarding the operating and installation conditions is required:
Installation Data
Length and profile of route (incl. height variations)
Details of laying arrangements (e.g. trefoil or flat arrangement)
Special conditions (e.g. water, heat, cold)
Underground cables;
Method of laying: Direct burial, in ducts or pipes, etc.
Spacing between cables and cable groups
Thermal resistivities and kinds of soil along the route
Depth of laying
Minimum, maximum and average ground temperatures
Cables in air;
Minimum, maximum and average ambient air temperatures
Type of installation (e.g. on racks) and details of arrangement
Details of ventilation (for cables in tunnels)
Whether exposed to direct sunlight
Special conditions, for example fire risk
Other parallel installed power cables, if any: Type and cross-sections of
conductors, carried load & load factor, voltage and layout details.
Data on termination layout details;
Switchgear
Power transformers
Overhead lines (type of conductor, cross-section and length)
Operating Conditions
Nominal voltage of system
Highest voltage of system
Impulse withstand voltage
System frequency
Maximum rated current;
for continuous operation
for cyclic operation (a load curve is essential)
for overload operation, if any (duration is
also essential)
Symmetrical and asymmetrical short-circuit
currents, both between phases and to earth.
Circuit breaker tripping time.
Required screen earthing: At both ends or single
point bonding or cross bonding
Required cable type
Accessories
Terminations (required type)
Joints
Others
Environmental conditions:
The altitude above sea level, if above 1000 m.
Whether excessive atmospheric pollution is
expected
High Voltage Cables
66 kV TO 400 kV COPPER WIRE SCREENED,
COPOLYMER COATED COPPER TAPE SHIELDED CABLES
Typical construction
XLPE insulated, copper wire screened, copolymer coated copper tape shielded,*
HDPE outer sheathed cables with copper or aluminium conductor
Main Properties
Radially and longitudinally watertight
Designed for usage in high fault current
Easy to handle
Lighter and more flexible than lead sheathed cables
Resistant to heavy vibrations
Available in long delivery lenghts to reduce number of joints
Corrosion-free screen area
* Copolymer coated aluminium tape can be applied instead of copolymer coated copper tape on request.
High Voltage Cables
66 kV TO 400 kV COPPER WIRE SCREENED,
LEAD SHEATHED CABLES
Typical construction
XLPE insulated, copper wire screened, lead sheathed, HDPE or PVC outer
sheathed cables with copper or aluminium conductor
Main Properties
Radially and longitudinally watertight
Suitable to carry high fault currents
Suitable for use in hostile environments or underground (at or near water table)
Corrosion and moisture resistant
Resistant to aggressive chemical substances
Offers good protection against rodents
High Voltage Cables
66 kV TO 400 kV LEAD SHEATHED CABLES
Typical construction
XLPE insulated, lead sheathed, HDPE or PVC outer sheathed cables with
copper or aluminium conductor
Main Properties
Radially and longitudinally watertight
Corrosion and moisture resistant
Suitable for use in hostile environments or underground (at or near water table)
Especially suitable for submarine installation
Resistant to aggressive chemical substances
Offers good protection against rodents
Lead sheath acts as a screen
XLPE INSULATED CABLES - TYPICAL CONSTRUCTIONS
Following data are typical values and are given only for information purposes. High voltage cables are
individually designed according to a given application.
Hence, specific values of high voltage cable designs are computed as part of the technical proposal.
TYPE OF CABLE 132 KV
(C u/ XL P E/ Cu-W/
Cu-T/HDPE)
220 KV (Cu / XL P E/ Pb-S/H DPE)
400 KV (Cu/XLPE/Cu-W/
Pb-S/HDPE)
Cross section
mm2
1x630
1x1400
1x2500
Diameter of conductor, approx. mm 30.6 47.2 63.5
Thickness of insulation mm 17 23 28 No.&diameter of copper wires in screen mm 60x1.42 – 86x1.45 Thickness of lead sheath Mm – 2.9 3.2 Thickness of copper tape (Copolymer coated) mm 0.20 – – Overall diameter, approx. mm 88 117 153 Weigh of cable, approx. kg/km 11,000 31,070 52,400 DC resistance of conductor at 20 °C Ω/km <0.0283 <0.0129 <0.0072 AC resistance of conductor at 90 °C:
- In flat formation, separation distance: 2D Ω/km 0.0383 0.0172 0.0108
- In trefoil formation Ω/km 0.0392 0.0178 0.0113_______
Max. permissible conductor temperature ° C 90 90 90
Max. permissible conductor temperature
during short-circuit ° C 250 250 250 Highest system voltage kV 145 245 420 Short duration power frequency
withstand voltage (at 20 °C for 1 minute) kV 275 460 610 Impulse withstand voltage kV 650 1050 1425 Permissible short circuit current
for conductor for 1 second kA 90.0 200.3 357.7 Permissible fault current for metallic sheath/
screen for 1 second kA 14.0 18.7 40.0 Operating capacitance at 20 °C µ F/km 0.18 0.20 0.213 Capacitance current per phase (at 50 Hz) A/km 4.3 8.0 14.7 Partial discharge at 1.5 x Uo pC <5 <5 <5 Dielectric loss factor, tan δ <10x10-4 <10x10-4 <10x10-4 Min. bending radius m 1.8 2.34 3.06 Max. pulling strength
(when pulling from conductor) kN 31.5 70 125 Max. side wall pressure kN/m 5 5 5
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TESTS OF CABLES & ACCESSORIES ACC. TO IEC 62067, IEC 60840
Routine tests of cables
Measurement of electrical resistance of conductor
Partial discharge test (max. 10 pC at 1.5Uo)
High voltage test (at 2.5Uo for 30 minutes)
Electrical test on outer sheaths (this is carried
out when required for a particular project,
depending on the function of the sheath)
Sample tests of cables
Conductor examination and measurement of
electrical resistance
Measurement of thickness of insulation, metallic
and non-metallic sheaths
Measurement of diameters, i f required
Hot set test for XLPE insulation
Measurement of capacitance
Lightning impulse (IEC 62067)
Water penetration test (IEC 62067; depending
on cable design)
Type tests on system; cable & accessories
a. Partial Discharge Test at ambient temperature
(max. 5 pC at 1.5Uo)
b. Tanδ Measurement (Required in IEC 62067)
c. Heating Cycle Voltage Test
d. Partial Discharge Tests
-at ambient temperature (max. 5 pC at 1.5Uo)
-at high temperature (max. 5 pC at 1.5Uo)
e. Impulse Voltage Test followed by a power
frequency voltage test
f. Tests of outer protection for buried joints.
g. Examination of the accesories after completion
of the tests.
Electrical tests after installation
Type test of cables
a. Electrical tests on completed cable:
Bending test followed by partial discharge test
(max. 5pC at 1.5Uo)
Tanδ measurement Heating cycle voltage test followed by partial
discharge measurements
Impulse withstand test followed by a power
frequency voltage test
b. Type tests on cable components:
Check of cable construction
Measurement of volume resistivity of extruded
semi-conducting layers
Tests for determining the mechanical properties
of insulation and non-metallic sheaths
Ageing test on pieces of completed cable to
check compatibility of materials
Loss of mass test on PVC sheaths
Pressure test at high temperature on sheaths
Test on PVC sheaths at low temperature
Heat shock test for XLPE insulation
Carbon black content of PE sheaths
Shrinkage test for XLPE insulation
Test under fire conditions (depending on cable
design)
Water penetration test (depending on cable
design)
Phase checking Measurement of DC resistance of conductor
Capacitance measurement
Measurement of insula tion res is tance
AC High Voltage test
Measurement of s equence impedances
DC Voltage test on outer sheats
In our laboratories, we can perform all necessary
tests of cables upto 400 kV rated voltage according
to IEC, BS, HD, VDE, NEMA, AEIC, ICEA, SS,
NFC, TS, GOST and other world standards and
customers specifications.
CABLE ACCESSORIES & CONTRACTING SERVICES
Cable Accessories
The quality of accessories is as important as the cable itself. Power failures
occur due to mishandling or improper conditions during installation works
as well as incorrect selection of accessories.
Accessories should withstand the operation related dimensional changes and
the working conditions as long as the service life of the cable. This can only
be achieved by proper accessories selection and meticulous attention to the
installation process.
Followings are the most important points to be followed:
Care must be exercised in stripping the semiconductive layer above the insulation without damaging
the insulation.
High degree of cleanliness must be maintained in preparing the insulation layer for jointing and
terminating processes according to instructions.
Insulation and inner semi-conductive materials of the joint must be identical to the material used
in the cable.
To avoid thermal stress during the operation of the cable system, it is highly recommended to use
fixing clamps to attach single core cables to walls, poles or consoles.
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CABLE ACCESSORIES & CONTRACTING SERVICES
Contracting Services
Demirer Kablo provides all the necessary services for the execution
of high voltage cable turnkey projects and partial cable system installations.
Our main services are;
Consulting
Site survey and system design
Most suitable cable design and accessories selection
Project design and engineering
Installation technique determination
Accessories selection & supply
Supply of the necessary equipment, tools and test devices for execution
Civil works
Steel construction works
Cable laying, mounting of accessories
Fault location, site testing
Supervision and commissioning
Training
Maintenance and repair
The most reliable and economical solutions are offered by evaluating the customer's requirements and the local conditions.
Demirer Kablo's Contracting group with its expertise in high voltage cable systems and with its skilled installation team
utilising modern installation, erection and test exuipment is willing to provide the best service to its customers.
400KV PREQUALIFICATION AND TYPE TEST REPORTS
DEM‹RER KABLO TESISLERI SANAYI ve TICARET A.š.
‹stanbul
Bozüyük Ankara
‹zmir
Head Office : Barbaros Bulvar› 49 Preveze Han
34353 Be•ikta• - ‹stanbul / TURKEY
Tel : +90 (212) 261 51 63 Pbx
+90 (212) 227 48 00 Pbx
Telefax : +90 (212) 258 16 56
+90 (212) 261 84 86
Factory : Yaft› Mevkii
Bozüyük / TURKEY
Tel : +90 (228) 314 28 00 Pbx
Telefax : +90 (228) 314 28 08
Contact e.mail addresses :
Export Sales Dept. : [email protected]
Local Sales Dept. : [email protected]
Technical Dept. : [email protected]
Purchasing Dept. : [email protected]
Web site : www.masscable.com.tr
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