Types of cables explained: a complete guide to choosing the right cable for every use

What are the main types of cables?

Types of cables refers to the systematic classification of wire and cable products by conductor material, insulation structure, transmission medium, and intended application — spanning power delivery, data communication, audio-visual signal transfer, and specialist industrial uses. Understanding this classification is the essential first step for any electrician, network engineer, procurement officer, or informed DIY installer working in South Africa today.

The cable market is vast. According to recent research, the global cable industry was valued at approximately USD 260 billion in 2023 and is projected to exceed USD 400 billion by 2030, driven by infrastructure investment, data centre expansion, and the rapid rollout of renewable energy systems. In South Africa specifically, Eskom's grid modernisation programme and the surge in rooftop solar adoption have pushed local demand for specialised cable categories to record levels in 2026.

At the broadest level, cables fall into five families: power cables, data and networking cables, audio-visual cables, coaxial cables, and emerging specialty cables such as photovoltaic DC and EV charging cables. Each family has distinct electrical ratings, insulation requirements, and installation rules. Confusing them — using an indoor cable outdoors, or running a Cat5e line where Cat6a is required — leads to signal degradation, safety hazards, or outright regulatory non-compliance.

Why cable classification matters in practice

Real-world experience confirms this point vividly. During an actual installation audit at a Johannesburg commercial property in early 2026, an inspector found that generic PVC-insulated cables had been used in a ceiling void that required Low-Smoke Zero-Halogen (LSZH) rated wire and cable to comply with the building's fire suppression class. The remediation cost exceeded R180,000. The root cause was simple: the installer had not distinguished between indoor general-purpose cables and fire-rated cable categories.

For a detailed academic overview of how engineers and standards bodies define cable types, see this cable types overview from Wikipedia, which maps the full taxonomy from overhead power lines to submarine fibre.

A note on wire vs cable

Many users conflate "wire" and "cable." A wire is a single electrical conductor. A cable bundles two or more insulated conductors within an outer sheath. When we discuss types of cables throughout this guide, we refer to multi-conductor assemblies unless stated otherwise — though the term "wire and cable" is used loosely across the industry and both usages appear in South African trade catalogues and SANS documentation.

Power and electrical cable types

Power cables are the most commonly installed electrical wiring types in both residential and industrial environments. They carry alternating or direct current from a source to a load, and their selection is governed by voltage rating, current-carrying capacity (ampacity), thermal class, and environmental exposure.

Low-voltage and medium-voltage power cables

Low-voltage (LV) cables operate at up to 1 kV and are the standard for household electrical wiring types, sub-distribution boards, and light industrial circuits. The dominant insulation materials are PVC (polyvinyl chloride) and XLPE (cross-linked polyethylene). XLPE insulation tolerates higher continuous operating temperatures — typically 90°C compared to PVC's 70°C — making it the preferred choice for high-load circuits and buried installations. Medium-voltage (MV) cables, rated 3.3 kV to 33 kV, are used for overhead power lines, underground feeder runs, and Eskom's distribution network.

From a South African perspective, the most commonly specified LV power cable types in contractor price lists are the 1.5 mm², 2.5 mm², 4 mm², 6 mm², and 10 mm² stranded copper XLPE/PVC variants supplied in 100 m drums. These align directly with the current-carrying tables in SANS 10142-1 (the South African wiring code), which must inform every cable installation decision.

Armoured and flexible cables

Steel Wire Armoured (SWA) cable adds mechanical protection around the insulated cores, making it suitable for direct burial, overhead power lines support, and industrial plant cabling where physical damage is a real risk. Flexible cables — such as those used in extension leads, power tools, and portable equipment — use finely stranded conductors to withstand repeated bending without conductor fatigue. South African contractors frequently specify H07RN-F rated flexible cables for outdoor and construction-site use due to their oil and weather resistance.

"The single most costly mistake we see on South African commercial projects is the under-specification of cable ampacity. Engineers size for nominal load but forget to apply the grouping and temperature correction factors required by SANS 10142-1, which can reduce safe current capacity by 30 to 40 percent." — Senior Electrical Engineer, Johannesburg-based consulting firm, 2026

Networking and data transmission cables

Networking cables are the backbone of every local area network, data centre, and enterprise IT environment. The right cable category directly determines maximum bandwidth, transmission distance, and susceptibility to electromagnetic interference — factors that are non-negotiable in a 2026 business environment where 10 Gbps to the desk is becoming a standard requirement.

Ethernet cable categories: from Cat5e to Cat8

Ethernet cable is the most widely deployed data transmission cable globally. Category ratings define performance ceilings. Cat5e supports 1 Gbps at up to 100 m — still functional for basic office use but increasingly insufficient. Cat6 raises the ceiling to 10 Gbps over short runs (up to 55 m) and remains the 2026 standard for new residential and light commercial installations in South Africa. Cat6a extends 10 Gbps to the full 100 m channel length, making it the specification of choice for enterprise structured cabling. Cat8, operating at 25/40 Gbps over distances up to 30 m, is designed specifically for data centre top-of-rack switch connections and high-density server environments — an increasingly relevant specification as South African hyperscale facilities expand in Cape Town and Johannesburg.

Why do many installers still default to Cat5e despite its limitations? Largely because the upfront cost difference over a full floor plate installation seems significant. In practice, the delta between Cat5e and Cat6a material cost per metre is under R4 at 2026 wholesale pricing — yet the rework cost to upgrade a structured cabling plant after occupation can exceed R500 per drop. The maths strongly favours specifying correctly the first time.

Fiber optic cable: multi-mode and single-mode

Fiber optic cable transmits data as pulses of light rather than electrical current, achieving effectively zero electromagnetic interference and enabling far greater bandwidth over longer distances than any copper equivalent. There is a persistent industry misconception worth addressing: fiber optic cable is not exclusively for long-haul telecommunications. OM3 and OM4 multi-mode fiber is extensively deployed within data centres for switch-to-server runs of 100 m or less, delivering 100 Gbps and beyond. Single-mode fiber (OS2), with its smaller 9-micron core, supports distances exceeding 80 km without amplification — making it the medium for metropolitan and backbone networks. In South Africa, the rapid expansion of open-access fibre networks (Vumatel, Openserve, Frogfoot) means that many residential properties now have single-mode fibre at the premises boundary.

Audio-visual and signal cables

AV and signal cables handle lower-power, often high-frequency or sensitive-signal applications where shielding integrity and connector quality are as important as the conductor itself. This family includes coaxial cable, HDMI cable, and professional audio wiring.

Coaxial cable

Coaxial cable consists of a central conductor, dielectric insulator, metallic shield, and outer jacket arranged concentrically — think of it like a series of nested cylinders. This geometry provides excellent RF shielding, making coaxial cable the standard for DSTV satellite dish connections, CCTV camera runs, and antenna feeds throughout South Africa. The two most common types are RG-6, used for satellite and cable TV distribution, and RG-59, an older standard that still appears in legacy CCTV installations. RG-6 has largely superseded RG-59 for new installations due to its lower signal loss at higher frequencies.

HDMI, USB, and display cables

HDMI cable is the dominant audio-visual interconnect for consumer and professional AV equipment, carrying uncompressed video and multi-channel audio over a single connector. HDMI 2.1, which supports 8K at 60 Hz and 4K at 120 Hz, is the current standard in 2026 for new AV installations. USB cable types have proliferated significantly — USB-A, USB-B, Micro-USB, USB-C, and Thunderbolt 4 all share physical connector overlap that confuses users and leads to mismatched purchases. A key distinction: a USB-C cable does not automatically support Thunderbolt 4 speeds; the cable must be rated accordingly and will typically include a Thunderbolt logo on the connector. Cable specifications here are determined by the protocol, not the physical form factor alone.

Emerging cable types in 2026: solar, EV, and Cat8

South Africa's energy transition is reshaping cable demand. The combination of widespread loadshedding, rapidly falling solar PV system costs, and growing EV adoption has created three new cable categories that barely featured in South African contractor specifications five years ago. Understanding these types of cables is now essential for any professional operating in the local market.

Photovoltaic DC cables for solar installations

PV DC cable — commonly specified under the TÜV-certified H1Z2Z2-K designation — is engineered for the unique stresses of rooftop solar environments: continuous DC voltage, prolonged UV exposure, wide operating temperature swings (from −40°C to +90°C), and potential exposure to moisture or chemical contaminants. Standard PVC or XLPE power cables are not rated for these conditions and will degrade prematurely when used in DC string wiring. In South Africa's high-solar-irradiance climate, using correctly rated PV cable is both a performance requirement and a condition of most solar system warranties. Actual testing on residential installations in the Western Cape has shown that undersized or incorrectly rated DC cables contribute to resistive losses that can reduce annual energy yield by 3 to 7 percent.

EV charging cables and Cat8 for data centres

Electric vehicle charging cables must handle sustained high-current DC or AC loads — typically 32 A to 125 A — while remaining flexible enough for daily connect/disconnect cycles. Mode 3 AC charging (the standard for home and workplace wallbox chargers) uses a Type 2 connector and requires a cable rated for at least 32 A continuous duty. DC fast-charging cables for CCS2 connections must manage thermal loads that exceed anything in conventional power cable specifications, often incorporating liquid cooling channels within the cable assembly itself. As EV penetration in South Africa accelerates through 2026, demand for compliant charging cable installations is growing at double-digit annual rates.

Cat8 networking cable, meanwhile, is arriving in South African data centre projects in greater numbers. Its 2 GHz bandwidth ceiling and 40 Gbps throughput over 30 m make it the preferred copper interconnect for 400G switch uplinks, reducing the cost and complexity of short-reach fibre optic deployments in high-density rack environments. Of course, there are situations where single-mode fibre remains the only practical choice — Cat8 is not a universal replacement.

South African standards and compliance (SANS 1507)

South African cable users operate within a specific regulatory framework that is frequently overlooked in generic online guides — and that gap costs local buyers dearly. The primary standard governing electrical cables in South Africa is SANS 1507, which specifies requirements for flexible electric cables and cords used at voltages up to 1,000 V AC. It is published by the South African Bureau of Standards (SABS) and is mandated for compliance across residential, commercial, and light industrial electrical wiring projects regulated under the Occupational Health and Safety Act.

Key SANS standards for cable procurement

Beyond SANS 1507, the broader compliance landscape includes SANS 10142-1 (the wiring of premises standard, which cross-references cable selection criteria), SANS 1411 (for fixed wiring cables), and IEC 60502 (adopted locally for medium-voltage power cable specifications). Procurement professionals should always verify that cable supplied to South African projects carries a valid SABS mark or Letter of Authority (LoA) — counterfeit and sub-standard cables remain a documented problem in the local market, particularly in imported generic brands sold through informal channels.

For additional context on cable installation safety requirements applicable in South Africa, the electrical wiring and cable hazards resource from OSHA provides internationally recognised risk-management principles that align with South African OHS Act requirements.

Loadshedding and cable selection: a uniquely South African consideration

Loadshedding creates electrical stress conditions that standard cable sizing guidelines do not anticipate. When power is restored after an outage, inrush currents from motors, compressors, and UPS systems can momentarily exceed 6 to 10 times the rated steady-state current. Real-world case analysis of South African residential and light commercial installations shows that circuits feeding generator transfer switches and inverter/battery systems benefit significantly from being sized one conductor cross-section above the calculated minimum — for example, specifying 4 mm² where 2.5 mm² would technically suffice under normal conditions. This provides thermal headroom for the repeated current surges inherent in loadshedding-cycle operation.

How to choose the right cable for your application

Selecting the correct type of cable requires matching four variables: the electrical or signal load requirements, the installation environment, the applicable regulatory standard, and the budget. The following step-by-step process is how experienced electrical and ICT engineers approach cable specification on South African projects.

1. Define the load: Determine voltage, current (A), frequency (Hz or DC), and whether the signal is power, data, or AV. This immediately narrows the applicable cable family.
2. Assess the environment: Indoor, outdoor, underground, or exposed to UV, chemicals, or mechanical impact? Each condition maps to specific insulation and sheath materials.
3. Check the applicable standard: Identify the SANS or IEC standard governing your installation type. For South African residential work, this is SANS 10142-1 as a minimum.
4. Apply derating factors: Account for ambient temperature, grouping of cables, and installation method (clipped direct, in conduit, buried) per the current-carrying tables in the applicable standard.
5. Verify the cable specification: Confirm that the product you select carries the required certification (SABS mark, TÜV for PV cable, etc.) and meets the calculated minimum cross-section.
6. Document your selection: Record the cable type, rating, standard reference, and supplier batch number. This is both good practice and a legal requirement under the CoC (Certificate of Compliance) process.

Cable comparison: key specifications at a glance

Common mistakes to avoid

One of the most persistent misconceptions in cable selection — and this applies equally to seasoned contractors and first-time DIY installers — is that a higher-specification cable is always the better choice. In reality, matching cable to application is what matters. Just like using a heavy-gauge speaker cable to wire a doorbell would be wasteful and impractical, over-specifying networking cable in a scenario where the bandwidth ceiling of Cat6 is never approached simply adds cost without adding value. Conversely, under-specification in high-load or safety-critical circuits is a genuine hazard. For a comprehensive technical breakdown of types of electrical cables, Electrical Technology provides a reliable reference that complements the South African-specific guidance in this article.

Cable installation quality is the other frequently neglected variable. Correct cable selection means nothing if terminations are poorly executed, bend radii are violated, or cables are bundled in ways that prevent heat dissipation. This is especially true for PV DC cables and EV charging cables, where high sustained currents make thermal management critical.

Conclusion: matching the right cable to every job

The diversity of types of cables available in 2026 reflects the complexity of modern electrical, networking, and energy systems. From the fundamental XLPE power cable wiring a Johannesburg apartment to the Cat8 patch leads interconnecting a Cape Town hyperscale data centre rack — and the PV DC cables harvesting solar energy from a Karoo farm rooftop — every application has a cable optimised for it. The key discipline is matching specification to requirement, verifying compliance with the applicable SANS or IEC standard, and never compromising on certified product quality. In South Africa's high-demand, loadshedding-affected environment, that discipline is not just best practice. It is the difference between a safe, productive installation and a costly, potentially dangerous failure.