Imagine a critical failure at a major mining operation where core equipment suddenly shuts down due to cables unable to withstand harsh working conditions. Preventing such incidents and ensuring stable power transmission requires careful selection of 22kV power cables. This article examines the technical parameters, applications, and selection criteria for these essential components.

22kV power cables, typically rated at 12.7/22kV, serve as fundamental components in medium-voltage distribution systems. While commonly associated with British standards (such as BS6622 PVC cables and BS7835 LSZH cables), the 12.7/22kV voltage rating also appears in other national standards, including South Africa's SANS specifications. Comparable to European 20kV cables, 22kV cables comply with IEC 60502-2 international standards. Both 22kV and 20kV cables share a maximum system voltage (Um) of 24kV.

Traditional 22kV cables predominantly use copper conductors for superior conductivity. However, aluminum conductors present a viable alternative where weight reduction is critical, though they require more installation space due to slightly lower conductivity.

Standard three-core 22kV cables typically feature either PVC or LSZH (Low Smoke Zero Halogen) insulation and sheathing. PVC offers excellent electrical insulation and weather resistance, while LSZH provides enhanced safety with reduced smoke emission and halogen-free composition during combustion. For applications demanding greater mechanical strength and environmental resistance, MDPE (Medium Density Polyethylene) sheathing is available.

British-standard cables often incorporate steel wire armoring for mechanical protection in direct burial applications. However, not all 22kV cables require armored protection. For instance, SANS 622 cables designed for heavy mobile equipment use nylon braiding reinforcement to enhance flexibility, making them ideal for mining applications.

Specialized applications may require extra insulation layers between copper wire screens and/or voltage equalization tapes to improve waterproofing and conductor protection.

Various international standards govern 22kV cable production to accommodate regional power system requirements:

• BS 6622: This British standard covers extruded insulation power cables rated from 3.8/6.6kV to 19/33kV, specifying construction, materials, electrical performance, and testing methods. BS 6622-compliant 22kV cables typically feature XLPE insulation with PVC outer sheathing and steel wire armoring for fixed installations.
• BS 7835: Similar to BS 6622 but utilizing LSZH (Low Smoke Zero Halogen) sheathing materials for enhanced safety in populated areas and public transport facilities.
• IEC 60502-2: The International Electrotechnical Commission's standard for extruded insulation power cables rated 1kV(Um=1.2kV) to 30kV(Um=36kV), covering design, manufacturing, testing, and installation requirements for global applications.
• SANS 622: South Africa's standard for mining rubber-sheathed cables, emphasizing flexibility and abrasion resistance for harsh mining environments.

As critical components in medium-voltage power transmission, 22kV cables serve diverse sectors:

• Power Systems: Connecting substations to distribution networks and supplying large industrial users, forming the backbone of urban and rural electricity grids.
• Industrial Operations: Powering heavy machinery, production lines, and infrastructure in factories, mines, and ports.
• Infrastructure Projects: Providing reliable electricity for airports, railways, tunnels, and other critical facilities.
• Renewable Energy: Connecting wind farms and solar power stations to main grids, facilitating clean energy distribution.

Proper cable selection requires comprehensive evaluation of multiple technical factors:

• Voltage Rating: Match cable specifications to the system's 12.7/22kV requirements to prevent safety hazards.
• Conductor Material: Balance conductivity needs with budget constraints, considering copper's superior performance versus aluminum's weight and cost advantages.
• Insulation Material: Select appropriate materials for operating environments - XLPE for high electrical/thermal performance, PVC for general weather resistance, or specialized materials for extreme conditions.
• Sheathing Material: Choose between PVC (general use), LSZH (high-safety areas), or PE (corrosive/water environments).
• Installation Method: Select cable structures suited to burial (armored), overhead (reinforced), or conduit (flexible) applications.
• Environmental Factors: Consider temperature, humidity, and chemical exposure when specifying cable properties.
• Compliance Standards: Verify adherence to relevant national and international standards like GB/T 12706 or IEC 60502.