The difference in voltage between high-voltage and low-voltage cables is immediately apparent from their names. High-voltage and low-voltage cables are classified according to their rated voltage. Below, we'll explain other differences between high-voltage and low-voltage cables.
1. Common Models and Structures of High-Voltage and Low-Voltage Cables
Low-voltage cables can be produced using both ordinary polyvinyl chloride and cross-linked polyethylene. Low-voltage cables are differentiated between cross-linked and ordinary types, while medium- and high-voltage cables are not, and are all cross-linked. Cables from 6kV to 35kV are produced using three-layer co-extrusion, high-density cross-linked polyethylene.
1. High-Voltage Cables
Common Cable Models: YJV-8.7/10kV, YJV22-8.7/10kV XLPE Insulated/Steel Tape Armored PVC Sheathed Power Cables
Structure: Conductor + Inner Shield + XLPE + Outer Shield + Copper Tape Shield + Filler + Non-Woven Fabric + Sheath
2. Low-Voltage Cables
Common Cable Models: VV/YJV PVC/XLPE Insulated/PVC Sheathed Power Cables
Structure: Conductor + Insulation + Filler + Wrapping Tape + Sheath
VV22/YJV22 PVC/XLPE Insulated, Steel Tape Armored, PVC Sheathed Power Cables
Structure: Conductor + Insulation + Filler + Wrapping Tape + Inner Liner + Steel Tape + Outer Sheath
High-voltage cables have an additional inner shield + XLPE + Outer Shield + Copper Tape Shield + Filler layer compared to low-voltage cables. Therefore, the insulation of high-voltage cables is much thicker, and the production process is more complex.
2. Differentiation between high-voltage and low-voltage cables
1. Check the cross-section. The innermost part of the cable is the conductive core (copper or aluminum core), and outwards are: insulation layer, semi-conductive layer, shielding layer, filling layer, steel protective layer, rubber protective layer (waterproof).
2. Check the thickness of the insulation layer:
(1) Low voltage (below 1kv) is 1~3mm thick, 10kv cable is 5~8mm, 35kv cable is about 10mm; low-voltage or weak-current cables generally have only one layer of insulation layer and protective layer.
(2) After removing the outer sheath, the high-voltage cable has an insulation layer, which is the main insulation layer wrapped around the cable core, white and plastic-like. Low-voltage cables do not have this main insulation layer, but only a rubber protective layer.
3. Check the voltage registration. The drawings generally have voltage levels such as YJV-1KV-4*150 or YJV-10KV-4*150.
Cables are usually divided into the following categories according to voltage levels: 1) Weak-current cables: 450/750V and below; 2) Low-voltage cables: 0.6/1kv; 3) Medium-voltage cables: 3-35kv; 4) High-voltage cables: 35-110kv; 5) Extra-high-voltage cables: 110-750kv.
