For XLPE insulated power cable,either chemical or physical method
is employed to transform the molecular structure of PE from chain
into three-dimensional network,i.e. thermoplastic PE is transformed
into thermosetting XLPE.After cross-linking,the thermal and
mechanical properties of PE have been greatly improved while tis
excellent electrical property are still retained.
The maximun permissible operating temperature of the conductor of a
XLPE insulated power cable is 90℃ which resistance is higher than
that of PVC or PE insulated power cable.The cable has the advantage
of simplicity in construction,lightness in weight,convenience in
application besides its excellent electrical,thermal,mechanical and
anti-chemical corrosion properties.It can also be laid with no
limitation of level difference along the route.
Product Standard
The product is manufactured according to the standard of
GB/T12706-2002 Eltruded solid dielectric power cables for rated
voltages from 1kV(Um=1.2kV) to 35kV（Um=40.5kVor IEC,BS,DIN and ICEA
upon request.
Applications
The product is suitable for use in power transmission and
distribution lines with rated power frequency voltage
3.6kV~26kV/35kV.
Operating characteristics
Rated power-frequency voltage U0/U：3.6/6kV~26/35kV.
Max. Permissible continuous operating temperature of conductor：90℃.
Max. short-circurt temperature of conductor shall not exceed
250℃（5s maximum duration）
Thte ambient temperature under installation should not below 0℃.
The bending radius of a single-core cable should not less than 20
times of the cable diameter.
The bending radius of a three-core cable should not less than 15
times of the cable diameter.
Voltage designation
The rated voltage of the cable for a given application shall be
suitable for the operating conditions in the system in which the
cable is used,and is expressed in the form of U0/U(UM)kV. Where:
U0—The rated power-frequency voltage between conductor and earth or
metallic screen,for which the cable designed;
U —The rated power-frequency voltage between conductors,for which
the cable designed;
Um—The maximum value of the highest system voltage” for which the
equipment may be used.
The values of U0 recommened for cable to be used in three-phase
systems are listed below.
U kV | Um kV | U0*kV |
System categories A and B | System categories C |
6 | 7.2 | 3.6 | 6 |
10 | 12 | 6 | 8.7 |
15 | 17.5 | 8.7 | 12 |
20 | 24 | 12 | 18 |
30 | 36 | 18 | — |
35 | 40.5 | 21 | 26 |
System category A—This category comprises those systems in which
any phase conductor that comes in contact with earth or an earth
conductor, is disconnected from the system with in 1 min.System
category B—This category comprises those system which,under fault
conditions, are operated for a short time with one phase
earthed.This period should not exceed 1h. For a longer period,not
exceeding 8h on ant occasion,can be tolerated.The total duration of
earth faults in any year should not exceed 125h.
System category C—This category comprises all systems which do not
fall into categories A and B.
Type of cable
Type | Designation | Application |
YJV | Copper conductor,XLPE insulated and PVC sheathed power cable | For laying indoors,in tunnel or cable trench,unable to bear
external mechanical forces.single core cable in megnetic duct is
not permissible. |
YJLV | Aluminium conductor,XLPE insulated and PVC sheathed power cable |
YJY | Copper conductor,XLPE insulated and PE sheathed power cable |
YJLY | Aluminium conductor,XLPE insulated and PE sheathed power cable |
YJV22 | Copper conductor,XLPE insu |
