Description
Application
Their aluminium wire armour (AWA) for single core cables and steel wire armour (SWA) for multicore cables provide robust mechanical protection making these MV cables suitable for direct burial in the ground. These armoured MV mains power cables are more commonly supplied with copper conductors but they are also available with aluminium conductors upon request to the same standard. The copper conductors are stranded (Class 2) whereas the aluminium conductors are compliant to the standard using both stranded and solid (Class 1) constructions.
Operating characteristics
1. Laying temperature: ≥0°C;
2. Cable conductor long-term allowable working temperature: PVC insulated ≤70°C, XLPE insulated ≤90°C;
3. Maximum operating temperature in case of short-circuit: PVC insulated ≤160°C, XLPE insulation ≤ 250°C;
4. Cable bending radius:
|
Item |
Single-core | Three-core | ||
| Non-armored | Armored | Non-armored | Armored | |
| Installation | 20D | 15D | 15D | 12D |
| Close to the terminal and connection box | 15D | 12D | 12D | 10D |
Note: D is the cable diameter
MV Cables Construction
| BS6622 | BS7835 | |
|---|---|---|
| Conductor | Class 2 stranded copper or Class 1 solid /Class 2 stranded aluminium | |
| Conductor Screen | Semi-conductive Cross-Linked Polyethylene (XLPE) | |
| Insulation | XLPE | |
| Insulation Screen | Semi-conductive XLPE | |
| Metallic Screen | Individual or overall copper tape | |
| Filler | Polyethylene Terephthalate (PET) fibres | |
| Separator | Binding Tape | |
| Bedding | Polyvinyl Chloride (PVC) | Low Smoke Zero Halogen (LSZH) compound |
| Armour | Single core cable: Aluminium Wire Armour (AWA) Multicore cable: Steel Wire Armour (SWA) |
|
| Sheath | PVC or Medium Density Polyethylene (MDPE) | LSZH |
| Rated voltage (kV) Sectional area (mm2) No. of core |
1st class | 0.6/1 | 1.8/3 | 3.6/6 | 6/10 | 8.7/15 | 12/20 | 18/30 | 21/35 |
| 2nd class | 1/1 | 3/3 | 6/6 | 8.7/10 | 12/15 | 18/20 | – | 26/35 | |
| 1 Core | 1.5-800 | 25-800 | 25-1200 | 25-1200 | 35-1200 | 50-1200 | 50-1200 | 50-1200 | |
| 2 Core | 1.5-185 | 25-185 | |||||||
| 3 Core | 1.5-400 | 25-400 | 25-400 | 25-400 | 35-400 | 50-400 | 50-400 | 50-400 | |
| 4 Core | 2.5-400 | 25-400 | |||||||
| 5 Core | 2.5-400 | 25-400 |
2). DC resistance: conductor resistance of the finished cable at 20ºC per kilometer is not more than the following values.
| Nominal section area (mm2) | 1.5 | 2.5 | 4 | 6 | 10 | 16 | 25 | 35 | 50 | 70 | 95 | 120 | 150 | 185 | 240 | 300 | 400 | 500 | 630 | 800 |
| Copper core | 12.1 | 7.41 | 4.61 | 3.08 | 1.83 | 1.15 | 0.727 | 0.524 | 0.387 | 0.268 | 0.193 | 0.153 | 0.124 | 0.099 | 0.0754 | 0.0601 | 0.047 | 0.0366 | 0.0283 | 0.0221 |
| Aluminum core | 18.1 | 12.1 | 7.41 | 4.61 | 3.08 | 1.91 | 1.2 | 0.868 | 0.641 | 0.443 | 0.32 | 0.253 | 0.206 | 0.164 | 0.125 | 0.1 | 0.778 | 0.0605 | 0.0469 | 0.0367 |
3). Voltage Test and Partial Discharge Test
| Rated voltage Uo (kV) Item |
0.6/1 | 1.8/3 | 3.6/6 | 6/6 6/10 | 8.7/10 8.7/15 | 12/20 | 18/20 18/30 | 21/35 | 26/35 | ||
| Voltage | Test voltage | 3.5 | 6.5 | 12.5 | 21 | 30.5 | 42 | 63 | 73.5 | 91 | |
| Test time | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | ||
| Partial discharge test | Test voltage | – | – | 6.2 | 10.4 | 15.1 | 20.8 | 31.1 | 36.3 | 45 | |
| Discharge capacity | – | – | 10 | 10 | 10 | 10 | 10 | 10 | 10 | ||
