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Medium Voltage Cables |  |
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| Medium Voltage Cables to BS 6622 |  |
Medium Voltage Cables to IEC 60502 | |
Medium Voltage Cables to VDE 0276 |
Medium Voltage Cables to IEC 60502
Single Core Cables to IEC 60502
Application
The single core cables are designed for distribution of electrical power with nominal voltage Uo/U ranging from
1.8/3KV to 18/30KV 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.
Standards
IEC 60502 Part 1(1.8/3KV)
IEC 60502 Part 2(3.6/6KV to 18/30KV
Construction
Conductor: Plain annealed copper or aluminium complying with IEC 60228 class 1 or 2.
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 conductor screen is not necessary for both
PVC and EPR/HEPR insulated 1.8/3KV and 3.6/6KV cables.
Insulation: Insulation is of polyvinyl chloride (PVC) intended for 1.8/3KV and 3.6/6KV cables, cross-linked
polyethylene compound (XLPE) or ethylene propylene rubber (EPR/HEPR).
Table 1. Insulation Thickness Of XLPE Or EPR/HEPR Insulation
| Nom. Cross Section Area |
Insulation Thickness at Nominal Voltage | |||||||
| 1.8/3KV (Um=3.6KV) |
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 | mm | ||
| XLPE/EPR | XLPE | EPR | XLPE/EPR | XLPE/EPR | XLPE/EPR | XLPE/EPR | ||
| Unscreened | Screened | |||||||
| 10 | 2.0 | 2.5 | 3.0 | 2.5 | - | - | - | - |
| 16 | 2.0 | 2.5 | 3.0 | 2.5 | 3.4 | - | - | - |
| 25 | 2.0 | 2.5 | 3.0 | 2.5 | 3.4 | 4.5 | - | - |
| 35 | 2.0 | 2.5 | 3.0 | 2.5 | 3.4 | 4.5 | 5.5 | - |
| 50 – 185 | 2.0 | 2.5 | 3.0 | 2.5 | 3.4 | 4.5 | 5.5 | 8.0 |
| 240 | 2.0 | 2.6 | 3.0 | 2.6 | 3.4 | 4.5 | 5.5 | 8.0 |
| 300 | 2.0 | 2.8 | 3.0 | 2.8 | 3.4 | 4.5 | 5.5 | 8.0 |
| 400 | 2.0 | 3.0 | 3.0 | 3.0 | 3.4 | 4.5 | 5.5 | 8.0 |
| 500 - 1600 | 2.2-2.8 | 3.2 | 3.2 | 3.2 | 3.4 | 4.5 | 5.5 | 8.0 |
*Insulation Thickness of PVC is 3.4mm (1- 1600mm sq) for 3.6/6KV cables.
Insulaton Screen:
The insulation screen consists of an extruded layer of 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. As an option, a semi-conducting tape may be applied
over the extruded semi-conducting layer as a bedding for the metallic layer. The minimum thickness is 0.3 mm
and the maximum resistivity is 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. The insulation screen is not necessary for both PVC and EPR/HEPR
insulated 1.8/3KV and 3.6/6KV cables. The screen may be covered by semi-conductive water blocking swellable
tape to ensure longitudinal watertightness.
Metallic Layer
The concentric copper screen wire is applied over the insulation, or over the insulation screen or over an inner
covering. As an alternative, copper tape(s) with minimum thickness of 0.1mm can be applied with overlap. Total
cross section of copper wire screen and copper tape screen layer are shown in Table 2a and 2b.
Table 2a. Total Cross Section and Max. DC Resistance of Copper Wire Screen
Nom. Cross Section Area of Conductor |
Total Cross Section |
Max. DC Resistance at 20 |
||||
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 |
Ω |
10 |
10 |
10 |
10 |
10 |
10 |
1.075 |
16 |
16 |
16 |
16 |
16 |
16 |
1.075 |
25 |
16 |
16 |
16 |
16 |
16 |
1.075 |
35 |
16 |
16 |
16 |
16 |
16 |
1.075 |
50 |
16 |
16 |
16 |
16 |
16 |
1.075 |
70 |
16 |
16 |
16 |
16 |
16 |
1.075 |
95 |
16 |
16 |
16 |
16 |
16 |
1.075 |
120 |
16 |
16 |
16 |
16 |
16 |
1.075 |
150 |
25 |
25 |
25 |
25 |
25 |
0.688 |
185 |
25 |
25 |
25 |
25 |
25 |
0.688 |
240 |
25 |
25 |
25 |
25 |
25 |
0.688 |
300 |
25 |
25 |
25 |
25 |
25 |
0.688 |
400 |
35 |
35 |
35 |
35 |
35 |
0.491 |
500 |
35 |
35 |
35 |
35 |
35 |
0.491 |
630 |
35 |
35 |
35 |
35 |
35 |
0.491 |
800 |
50 |
50 |
50 |
50 |
50 |
0.344 |
1000 |
50 |
50 |
50 |
50 |
50 |
0.344 |
Table 2a. Total Cross Section and Max. DC Resistance of Copper Tape Screen (0.1mm)
Nom. Cross Section Area of Conductor |
Total Cross Section & Max. DC Resistance |
|||||||||
3.6/6KV (Um=7.2KV) |
6/10KV (Um=12KV) |
8.7/15KV (Um=17.5KV) |
12/20KV (Um=24KV) |
18/30KV (Um=36KV) |
||||||
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
|
mm² |
mm |
|
mm |
|
mm |
|
mm |
|
mm |
|
10 |
4.7 |
3.646 |
- |
- |
- |
- |
- |
- |
- |
- |
16 |
5.1 |
3.342 |
5.9 |
2.925 |
- |
- |
- |
- |
- |
- |
25 |
5.7 |
3.025 |
6.4 |
2.679 |
7.3 |
2.350 |
8.1 |
2.114 |
- |
- |
35 |
6.2 |
2.796 |
6.9 |
2.498 |
7.8 |
2.210 |
8.6 |
2.000 |
- |
- |
50 |
6.7 |
2.568 |
7.4 |
2.314 |
8.3 |
2.064 |
9.1 |
1.880 |
11.2 |
0.579 |
70 |
7.4 |
2.314 |
8.2 |
2.106 |
9.1 |
1.897 |
9.9 |
1.740 |
11.9 |
0.543 |
95 |
8.2 |
2.095 |
8.9 |
2.925 |
9.8 |
1.748 |
10.7 |
1.614 |
12.7 |
0.510 |
120 |
9.0 |
1.905 |
9.8 |
2.679 |
10.7 |
1.613 |
11.5 |
1.498 |
13.5 |
0.479 |
Nom. Cross Section Area of Conductor |
Total Cross Section & Max. DC Resistance |
|||||||||
3.6/6KV (Um=7.2KV) |
6/10KV (Um=12KV) |
8.7/15KV (Um=17.5KV) |
12/20KV (Um=24KV) |
18/30KV (Um=36KV) |
||||||
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
Total Cross Section |
Max. DC |
|
mm² |
mm |
|
mm |
|
mm |
|
mm |
|
mm |
|
150 |
9.7 |
1.781 |
10.4 |
2.498 |
11.3 |
1.523 |
12.1 |
1.420 |
14.2 |
0.458 |
185 |
10.6 |
1.626 |
11.2 |
2.314 |
12.2 |
1.407 |
12.9 |
1.335 |
14.9 |
0.434 |
240 |
11.7 |
1.465 |
12.4 |
2.106 |
2.106 |
1.294 |
14.1 |
1.219 |
16.2 |
0.401 |
300 |
12.9 |
1.334 |
13.4 |
1.923 |
1.923 |
1.204 |
15.1 |
1.139 |
17.1 |
0.378 |
400 |
14.3 |
1.205 |
14.6 |
1.761 |
1.761 |
1.110 |
16.3 |
1.054 |
18.4 |
0.353 |
500 |
15.7 |
1.094 |
16.2 |
1.655 |
1.655 |
1.005 |
17.5 |
0.982 |
20.0 |
0.325 |
630 |
17.3 |
0.992 |
18.9 |
1.540 |
1.540 |
0.918 |
19.5 |
0.880 |
21.6 |
0.300 |
800 |
20.3 |
0.849 |
20.4 |
1.388 |
21.3 |
0.807 |
22.1 |
0.777 |
24.2 |
0.268 |
1000 |
22.3 |
0.771 |
22.4 |
1.285 |
23.3 |
0.738 |
24.1 |
0.713 |
26.2 |
0.248 |
Separation Sheath (for armoured cable):
The separation sheath comprises a layer of extruded PVC, PE or LSZH, applied under the armour .The nominal
thickness is calculated by 0.02Du + 0.6mm where Du is the fictitious diameter under the sheath in mm. For
cables without a lead sheath, the nominal separation sheath thickness shall not be less than 1.2mm. For cables
where the separation sheath is applied over the lead sheath, the nominal separation sheath thickness shall not
be less than 1.0mm.
Lapped Bedding (for armoured lead sheathed cable):
The lapped bedding consists of either impregnated/synthetic compounded paper tapes or a combination of two
layers of these paper tapes followed by a few layers of compounded fabulous materials. The thickness is around
1.5mm.
Armour (for armoured cable):
The armour consists of round aluminium wire armour applied helically over an extruded separation sheath.
Table 3. 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 | 2.0 |
| 35 | 60 | 2.5 |
| 60 | - | 3.15 |
Over Sheath:
Overall sheath comprises a layer of extruded thermoplastic compound (PVC, PE or LSZH can be offered as an
option.) or elastomeric compound (polychlorprene CSP or chlorosulfonated PE). The nominal oversheath
thickness is calculated by 0.035D+1 where D is the fictitiuous diameter immediately under the oversheath in mm.
For unarmoured cables and cables with the oversheath not applied over the armour, metallic screen or
concentric conductor, the nominal oversheath thickness shall not be less than 1.4mm. And for cables with
oversheath applied over the armour, metallic screen or concentric conductor, the nominal oversheath thickness
shall not be less than 1.8mm.
PHYSICAL PROPERTIES:
Operating Temperature: up to 70°C (PVC insulation); up to 90°C (XLPE or EPR insulation)
Temperature Range: -5°C ( PVC sheath ); -20°C ( PE sheath )
Short Circuit Temperature( 5 seconds maximum duration ): 140-160°C (PVC insulation);
250°C (XLPE or EPR insulation)
Bending Radius: 20 x OD
Table 4. Nominal /Operating /Testing Voltages
| Rated Voltage Uo/U | Operating Voltage (Um) | Testing Voltage (rms) |
| 1.8/3KV | 3.6KV | 6.5KV |
| 3.6/6KV | 7.2KV | 12.5KV |
| 6/10KV | 12KV | 21KV |
| 8.7/15KV | 17.5KV | 30.5KV |
| 12/20KV | 24KV | 42KV |
| 18/30KV | 36KV | 63KV |
*21/35KV and 26/35kV power frequency voltage test can be made under the following conditions: 2.5Uo x
30mins or 3.0Uo x 15mins. Numbers in brackets refer to the test values for 3.0Uo x 1.5mins.
Single Core 1.8/3KV (Um=3.6KV) Dimensional Data
Nom. Cross- Section Area |
|
Unarmoured Cables |
Steel Wire Armoured Cables |
||||||||
Nom. Insulation Thickness |
Nom. Sheath Thickness |
Approx. Overall Diameter |
Approx. Weight |
Nom. Bedding Thickness |
Armour Wire Size |
Nom. Sheath Thickness |
Approx. Overall Diameter |
Approx. Weight |
|||
CU |
AL |
CU |
AL |
||||||||
mm² |
mm |
mm |
mm |
kg/km |
mm |
mm |
mm |
mm |
kg/km |
||
10 |
2.0 |
1.8 |
13 |
240 |
180 |
1.2 |
1.6 |
1.8 |
18 |
460 |
400 |
16 |
2.0 |
1.8 |
13 |
300 |
200 |
1.2 |
1.6 |
1.8 |
19 |
530 |
430 |
25 |
2.0 |
1.8 |
15 |
410 |
250 |
1.2 |
1.6 |
1.8 |
20 |
650 |
500 |
35 |
2.0 |
1.8 |
16 |
510 |
300 |
1.2 |
1.6 |
1.8 |
21 |
780 |
560 |
50 |
2.0 |
1.8 |
17 |
640 |
350 |
1.2 |
1.6 |
1.8 |
22 |
930 |
640 |
70 |
2.0 |
1.8 |
19 |
850 |
440 |
1.2 |
1.6 |
1.8 |
24 |
1170 |
750 |
95 |
2.0 |
1.8 |
20 |
1130 |
540 |
1.2 |
1.6 |
1.8 |
26 |
1460 |
870 |
120 |
2.0 |
1.8 |
22 |
1370 |
630 |
1.2 |
1.6 |
1.8 |
27 |
1730 |
990 |
150 |
2.0 |
1.8 |
23 |
1650 |
730 |
1.2 |
1.6 |
1.8 |
29 |
2030 |
1110 |
185 |
2.0 |
1.8 |
25 |
2010 |
860 |
1.2 |
1.6 |
1.9 |
30 |
2430 |
1280 |
240 |
2.0 |
1.8 |
27 |
2570 |
1050 |
1.2 |
1.6 |
2.0 |
33 |
3040 |
1530 |
300 |
2.0 |
1.8 |
29 |
3160 |
1250 |
1.2 |
2.0 |
2.1 |
36 |
3760 |
1860 |
400 |
2.0 |
1.9 |
33 |
3980 |
1560 |
1.2 |
2.0 |
2.2 |
39 |
4660 |
2230 |
500 |
2.2 |
2.1 |
35.5 |
4910 |
1905 |
1.3 |
2.5 |
2.5 |
43 |
5930 |
2930 |
630 |
2.4 |
2.2 |
39.7 |
6340 |
2420 |
1.4 |
2.5 |
2.6 |
49 |
7370 |
3430 |
800 |
2.6 |
2.3 |
44.5 |
7890 |
2980 |
1.4 |
2.5 |
2.7 |
52 |
9070 |
4230 |
1000 |
2.8 |
2.5 |
49.4 |
9890 |
3700 |
1.5 |
2.5 |
2.9 |
56 |
11100 |
4950 |
Electrical Data
Nom. Cross- Section Area |
D C |
A C |
Short Circuit Rating of Conductor CU / AL |
Capaci- tance |
Charging Current |
Reactance |
Inductance |
Impedance |
|||||
Trefoil |
Flat Spaced |
Trefoil |
Flat Spaced |
Trefoil |
Flat Spaced |
||||||||
CU |
AL |
CU |
AL |
||||||||||
mm² |
µΩ/m |
µΩm |
kA |
pF/m |
mA/m |
µΩ/m |
nH/m |
µΩ/ m |
µΩ/ m |
||||
10 |
1830/3080 |
2330/3920 |
1.4/0.9 |
182 |
0.27 |
151 |
201 |
384 |
558 |
2332 |
3846 |
2332 |
3840 |
16 |
1150/1910 |
1460/2420 |
2.2/1.4 |
201 |
0.29 |
140 |
193 |
362 |
546 |
1462 |
2411 |
1478 |
2420 |
25 |
727/1200 |
927/1538 |
3.6/2.3 |
222 |
0.32 |
131 |
185 |
345 |
535 |
936 |
1544 |
952 |
1554 |
35 |
524/868 |
668/1113 |
5.0/3.2 |
251 |
0.35 |
122 |
178 |
327 |
524 |
679 |
1121 |
695 |
1131 |
50 |
387/641 |
494/822 |
6.8/4.4 |
281 |
0.39 |
116 |
172 |
313 |
514 |
511 |
834 |
527 |
844 |
70 |
268/443 |
343/568 |
9.8/6.3 |
341 |
0.45 |
110 |
165 |
300 |
495 |
364 |
583 |
386 |
597 |
95 |
193/320 |
248/410 |
13.3/8.5 |
397 |
0.50 |
104 |
160 |
287 |
485 |
272 |
427 |
300 |
446 |
120 |
153/253 |
196/325 |
17.2/11.0 |
430 |
0.55 |
104 |
159 |
283 |
480 |
225 |
345 |
257 |
367 |
150 |
124/206 |
159/266 |
21.2/13.5 |
464 |
0.59 |
100 |
156 |
280 |
475 |
193 |
287 |
229 |
313 |
185 |
99/164 |
128/211 |
26.6/17.0 |
513 |
0.65 |
98 |
154 |
274 |
465 |
165 |
237 |
206 |
267 |
240 |
75/125 |
98/161 |
34.9/22.3 |
573 |
0.70 |
94 |
150 |
267 |
459 |
140 |
191 |
185 |
226 |
300 |
60/100 |
80/130 |
43.8/28.0 |
652 |
0.72 |
91 |
147 |
260 |
455 |
128 |
163 |
174 |
203 |
400 |
47/78 |
64/102 |
57.3/36.6 |
727 |
0.75 |
90 |
147 |
253 |
445 |
113 |
141 |
164 |
184 |
500 |
37/60 |
51/81 |
72.3/46.2 |
754 |
0.79 |
89 |
145 |
248 |
435 |
105 |
124 |
158 |
171 |
630 |
28/47 |
42/64 |
91.2/58.3 |
786 |
0.87 |
86 |
143 |
245 |
425 |
97 |
110 |
151 |
160 |
800 |
22/37 |
35/55 |
114.4/75.0 |
846 |
0.91 |
85 |
142 |
243 |
415 |
92 |
101 |
147 |
153 |
1000 |
18/29 |
30/46 |
143.0/94.0 |
916 |
0.99 |
83 |
141 |
239 |
405 |
88 |
95 |
144 |
148 |
Single Core 3.6/6KV (Um=7.2KV)
Single Core 6/10KV (Um=12KV)
Single Core 8.7/15KV (Um=17.5KV)
Single Core 12/20KV (Um=24KV)
Single Core 18/30KV (Um=36KV)
Single Core 21/35KV (Um=42KV)
Current Rating for Single Core 1.8/3KV(Um=3.6KV ) to 26/35KV(Um=42KV)
Current Rating Conditions:
Ground Temperature: 20°C
Ambient Temperature (air): 30°C
Depth of Soil: 0.8m
Thermal Resistance of Soil: 1.5K•m/W