Cable Sheath Protection

Cable Sheath Protection

Cable sheath protection Picture Show Explanation Large cross-section 35kV power cables and 66kV, 110kV and above voltage level of power cables are single-core cable, one end of the cable metal sheath phase interconnected and grounded and the other end is not grounded, when lightning or internal...
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Product Details

Cable sheath protection


Picture Show

新建 DOC 文档39.jpg

Explanation

Large cross-section 35kV power cables and 66kV, 110kV and above voltage level of power cables are single-core cable, one end of the cable metal sheath phase interconnected and grounded and the other end is not grounded, when lightning or internal over-voltage waves along the cable core flow, the cable metal sheath without ground terminal will appear higher impact overvoltage,short circuit or when the system fault current flows through the cable core, its protective layer does not also appear high groundfrequency induction overvoltage. The over-voltage can penetrate the cable outer sheath insulation, causing the cable metal sheathmulti-point ground fault, seriously affecting the normal operation of power cables or even substantially reduce cable life. Thus the power industry standard DL/T401-1991 "high voltage power cable guide for the selection," states: cable sheath must be used to limit the power cable protection metal shield (or metal sheath) on the induced voltage and over-voltage fault.


Product Features

Grounded at one end of the cable company for crossover interconnection lines and cable lines designed silicon rubber cable sheath protector has the following characteristics:
1, low residual voltage using a large-capacity high-quality ZnO chip with through flow, protection ratio characteristics;
2, the maximum limit, reducing the metal sheath cable lines in frequency induction over-voltage and over-voltage shocks;
3, integrally molded silicone rubber jacket, good sealing, anti-fouling ability, light weight, small size, anti-collision, heat resistance, aging, maintenance-free;
4, such as configuration discharge counter or monitor can automatically and accurately recorded in a variety of over-voltageprotection actions under the number and quality of operation.


Explanation

model

System amount

Constant voltage

kV

Power frequency resistance

Pressure/

time

kV/s

10kA lightning

Under current

≤kVp

DC U1mA

Reference voltage

≥kV

2ms square wave

Flow capacity

A

Under 0.75U1mA

Leakage current

≤μA

Currently in the market

Model number marked by country line

LHQ-6

6

1.9/4

4.6

2.1

400

50

BHQ、BYL、
FBY、SHQ、
BYLS、TBP-D

LHQ-10

10

3.6/4

8.7

4.0

400

50

LHQ-35

35

5/4

12

5.5

400

50

LHQ-110(Ⅰ)

110

6/4

15

6.5

400

50

LHQ-110(Ⅱ)

110

10/4

25

11.0

400

50

LHQ-220(Ⅰ)

220

6/4

12

5.8

400

50

LHQ-220(Ⅱ)

220

13.6/4

31

15

400

50

LHQ-500

500

7.5/4

8*

8.3

400

50

*Note: Residual voltage at lightning impulse current of 16kA


Cable sheath insulation withstand voltage value (DL/T401-1991) "voltage power cable guide for the selection"

Cable Rated voltage / Rated voltage system
Ue/U

1min Frequency withstand voltage
kV

Workers lightning impulse withstand voltage
kVp

37/63、48/63、64/110

24

37.5

127/220

24

47.5

190/330

24

62.5

290/500

24

72.5


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