Regulations on structure of medium voltage cables

The content is specified as follows:

1. TCVN 5935-1:2013 – Part 1

Cables for rated voltages of 1 kV (Um = 1.2 kV) and 3 kV (Um = 3.6 kV).

1. The rated voltage Uo/U(Um) of the cables considered in this standard is 1.8/3 (3.6) kV.
2. Insulating compound
   1. PVC thermoplastic;
   2. Cross-linked insulating compound: Ethylene propylene rubber or the like (EPR), molecular rubber or high hardness ethylene propylene rubber (HEPR), Cross-linked polyethylene (XLPE).
3. The maximum conductor temperature in normal operation is 70 degrees C (if PVC insulation) and 90 degrees C (if XLPE insulation).
4. Conductors: Must be class 1 (1 solid conductor) or class 2 (braided conductor) (according to IEC 60228:2004) of annealed copper/coated with aluminum or aluminum alloy;
5. Regulations on the minimum thickness of each insulating compound on each product classified according to the following nominal cross-sections: 1.5 and 2.5mm2, 4 and 6mm2, 10 and 16mm2, 25 and 35mm2, 50mm2, 70mm2, 95mm2, 120mm2, 150mm2, 185mm2, 240mm2, 300mm2…
6. Thickness of extruded, wound inner coating (0.4mm);
7. Maximum resistance: The measured resistance value must be corrected to a temperature of 20 degrees C and 1 km of length according to the formula and coefficient stated in IEC 60228.

2. TCVN 5935-2:2013 – Part 2

Power cables for rated voltages from 6 kV (Um = 7.2 kV) to 30 kV (Um = 36 kV).

1. The rated voltage Uo/U(Um) of the cables considered in this standard is as follows: Uo/U(Um) = 3.6/6 (7.2) – 6/10 (12) – 8.7 /15 (17.5) – 12/20 (24) – 18/10 (36) kV.
2. Insulating compound
   1. PVC/B for cable lines with rated voltage Uo/U = 3.6/6 kV;
   2. Thermosetting plastic: Ethylene propylene rubber or similar (EPR), High hardness ethylene propylene rubber or rubber (HEPR), Cross-linked polyethylene (XLPE);
   3. Maximum conductor temperature in normal operation: For PVC/B it is 70 degrees Celsius, for EPR/ HEPR/ XLPE it is 90 degrees Celsius.
3. Conductors: shall be class 1 (1 solid conductor) or class 2 (braided conductor) of metallized annealed copper with aluminum/aluminum alloy in accordance with IEC 60228.
4. Specifies the nominal thickness of insulation layers PVC/B, XLPE, EPR/HEPR;
5. Specifications for three-core cable assemblies, inner sheaths and fillers.