Introduction

South Africa’s industrial, mining, and municipal power networks rely heavily on robust low-voltage (LV) cabling systems. Among all the LV cable types used across the country, SANS 1507-3 Steel Wired Armoured (SWA) PVC 0.6/1kV cables stand out as some of the most widely installed and most trusted.

These cables are everywhere—from municipal LV distribution lines in rural KwaZulu-Natal, to conveyor motors in Rustenburg’s platinum mines, to auxiliary circuits in Northern Cape solar farms. Their popularity stems from a combination of durability, mechanical protection, flame retardance, reliability, and affordability.

To avoid confusion, South African engineers often compare:

• SANS 1507-3 → PVC insulated (70°C), PVC sheathed SWA cable, black with blue stripe

• SANS 1507-4 → XLPE insulated (90°C), PVC sheathed SWA cable, black with red stripe

Even though the two look similar, they serve different engineering purposes.

This article unpacks everything professionals need to know about SANS 1507-3—from structure and specs to real-world performance in South Africa.

Understanding the SANS 1507 Cable Series

What Exactly Is SANS 1507-3?

SANS 1507-3 is the authoritative South African standard governing:

• PVC insulated

• PVC bedded

• PVC sheathed

• Steel Wire Armoured (SWA)

• Low-voltage 0.6/1kV power cables

These cables are flame retardant (IEC 60332-1-2) and designed for fixed installations—both indoor and outdoor, including direct burial in free-draining soil.

The standard defines everything: conductor size, insulation thickness, mechanical properties, electrical ratings, colour identification, and testing requirements.

Difference Between SANS 1507-3 and SANS 1507-4

Why it matters:
PVC insulation has a lower temperature tolerance, so when engineers calculate current rating, SANS 1507-4 XLPE cables carry more current at the same size.

However, SANS 1507-3 remains more cost-effective and perfectly adequate for most LV circuits in South Africa where temperature rise is moderate.

Cable Construction Explained

Understanding cable construction helps engineers evaluate durability, performance, and suitability for harsh South African conditions.

Conductor – Stranded Copper (Class 2)

Copper continues to dominate South African LV power distribution because of:

• Superior conductivity

• Excellent corrosion resistance (important in coastal areas)

• Mechanical strength

• High reliability in fault conditions

South Africa’s utilities (ESKOM and municipal distributors) overwhelmingly prefer copper SWA cables for LV feeders.

PVC Insulation

PVC is widely used because it offers:

• Solid dielectric performance

• Flame retardance

• Cost-effective installation

• Flexibility for smaller core sizes

• Temperature range: –20°C to +70°C

Climate considerations:
The Highveld reaches over 35°C in summer, and coastal regions are humid—but PVC holds up well in both environments, making SANS 1507-3 ideal for national use.

PVC Bedding Layer

The bedding provides:

• A cushion between insulation and armour

• A smooth surface to prevent abrasion

• Additional mechanical protection

It ensures the armour wires maintain proper alignment.

Steel Wire Armour (SWA)

Made from galvanised steel, the armour provides:

• High mechanical protection for direct burial

• Resistance to rocks, tools, and accidental digging

• Excellent rodent protection (critical in rural KZN and Limpopo)

• A reliable earth-fault return path (for multi-core cables)

SWA is one of the main reasons SANS 1507-3 cables survive decades in demanding field conditions.

Outer PVC Sheath (Black with Blue Stripe)

The sheath offers:

• Weather and UV resistance

• Additional abrasion protection

• Chemical and oil resistance

• Identification through the blue stripe (mandatory marking)

Blue = PVC insulated
Red = XLPE insulated

Incorrect identification has caused installation errors in the past—hence the importance of visible stripe markings.

Core Identification

South Africa follows traditional core colours:

• 2-Core: Red, Yellow

• 3-Core: Red, Yellow, Blue

• 4-Core: Red, Yellow, Blue, Black

This helps maintenance teams quickly identify phases and neutrals during fault repairs or terminations.

Technical Specifications

Voltage & Temperature Rating

• Uo/U = 0.6/1kV

• Max conductor temperature: 70°C

• Installation temperature: ≥ –20°C

Complies fully with municipal LV distribution requirements for feeders, street lighting, pump stations, and commercial buildings.

Mechanical Characteristics

Minimum bending radius:

• Small sizes (1.5–16mm²): 6 × overall diameter

• 25mm² and above: 8 × overall diameter

Armour allows direct burial without conduits—reducing installation cost.

Dimensional Overview

Cross-sectional areas range from 1.5mm² up to 240mm².

Larger sizes provide:

• Lower resistance

• Higher current carrying capacity

• Lower voltage drop

• Better performance for long rural lines

This is especially relevant for long feeder lines in remote electrification projects.

Electrical Characteristics

Conductor DC Resistance

Resistance decreases as core size increases. Engineers calculate voltage drop using these values, especially for:

• Long farm connections

• Mine camp power lines

• Solar plant auxiliary circuits

Voltage drop is a common concern in rural Limpopo and Eastern Cape installations where feeder distance is long.

Current Carrying Capacity

Depends on:

• Soil thermal resistivity

• Ambient temperature

• Installation method

• Number of cables grouped

SANS 1507-3 cables have lower current ratings than SANS 1507-4 (because PVC handles less heat), but they remain sufficient for:

• Urban distribution

• Building feeds

• Industrial MCC circuits

Short-Circuit Performance

PVC insulation can withstand high temperatures for short durations. SWA armour provides a robust fault return path, which is critical in:

• Mining substations

• MCC (Motor Control Centres)

• Municipal LV switchboards

Applications in South Africa

General Use

Suitable for:

• Direct burial

• Cable trays

• Building service feeders

• Pump and motor circuits

• Street lighting systems

Mining Sector

Mining relies heavily on SWA armoured cables because they:

• Resist crushing and impact

• Survive harsh, abrasive environments

• Provide stable LV power for conveyors, pumps, and underground lighting

SANS 1507-3 is widely used in:

• Gold mines (Gauteng)

• Platinum mines (North West)

• Coal mines (Mpumalanga)

Energy & Infrastructure

Common in:

• Municipal LV networks

• Renewable energy plants

• Commercial complexes

• Industrial automation circuits

Solar farms use SWA PVC cables for:

• AC auxiliary power

• Control rooms

• Inverter station connections

Petrochemical & Industrial

Because of the flame-retardant PVC sheath, these cables are ideal for:

• Factories

• Processing plants

• Warehouses

• Fuel storage areas

South African Case Studies

Case Study 1 – Rustenburg Platinum Mines

Application: Conveyor drive motors
Cable Type: 3-core 35mm² SANS 1507-3
Reason for Choice:

• PVC insulation suitable for moderate temperature rise

• SWA armour preventing mechanical damage from rocks and loaders

• Cost-effective for long runs

Outcome: Mechanical failure rate reduced by over 40% after replacing unarmoured cables.

Case Study 2 – KwaZulu-Natal Rural Electrification

Application: LV feeder lines to villages
Cable Type: 4-core 16mm² SANS 1507-3
Benefits:

• Direct burial reduces installation time

• Armour protects from rodents and accidental digging

• Stable long-distance performance

Result: Noticeable reduction in supply outages compared to older PVC unarmoured cables.

Case Study 3 – Northern Cape Solar Plant

Application: Auxiliary LV circuits
Challenge: Extreme ambient temperatures (40°C–45°C)
Solution: SANS 1507-3 SWA cables with UV-resistant sheath
Advantages:

• Armour resists termite damage

• PVC sheath withstands sun and dust

• Long service life under harsh climate

Compliance, Testing & Safety Requirements

SANS 1507-3 Compliance

South African projects require cables to meet:

• Dimensional accuracy

• Mechanical performance

• Electrical resistance

• Voltage withstand tests

• Flame retardance

Local inspectors check:

• Markings

• Blue stripe identification

• Manufacturer certifications

Flame Retardance – IEC 60332-1-2

This is not fire resistance—rather flame retardance, meaning the cable won’t propagate fire. Essential for:

• Buildings

• Tunnels

• Mining environments

Procurement Quality Assurance

Engineering teams should check:

• SANS markings

• Batch numbers

• Armour quality (galvanisation)

• Outer sheath thickness

• Conductor purity

Fake or non-compliant cables have caused faults in several municipal projects—QA is essential.

Selecting the Right SANS 1507-3 Cable

Key Selection Factors

Consider:

• Load current

• Voltage drop

• Cable run length

• Soil thermal conditions

• Mechanical protection needs

• Whether the environment is hot or abrasive

Installation Guidelines

Key recommendations:

Direct Burial

• Use free-draining soil

• Maintain spacing for heat dissipation

• Avoid sharp stones

• Place warning tape above cable

Bending Radius

• Follow 6× or 8× overall diameter guidelines

Terminations

• Use proper SWA glands

• Ensure correct earthing of armour

• Seal glands against moisture ingress

Common Mistakes to Avoid

• Overbending

• Using incorrect glands

• Identifying PVC cable as XLPE due to missing stripe

• Directly exposing sheath to chemicals not compatible with PVC

Frequently Asked Questions (FAQ)

1. Is SANS 1507-3 suitable for underground mining?
Yes, for fixed installations, pump rooms, lighting, and MCC circuits.

2. Can it be installed directly in soil?
Yes. SWA armour provides full mechanical protection.

3. What is the difference between SWA and AWA?
SWA = Steel Wire Armour
AWA = Aluminium Wire Armour (used only for single-core due to magnetic fields)

4. When should I choose SANS 1507-3 vs SANS 1507-4?
1507-3 for cost-effective general use;
1507-4 for higher temperatures or higher current loading.

5. Does PVC insulation affect performance in hot climates?
Only if ambient temperature is close to limits—in such cases XLPE is preferred.

6. How do I identify authentic SANS-approved cables?
Look for markings + blue stripe + manufacturer certificate.

7. Can SANS 1507-3 be used in coastal environments?
Yes, galvanised armour resists corrosion, but regular inspection is recommended.

8. What size should I choose for a 100m motor feeder?
Depends on current rating and voltage drop—typically 16–35mm² for small motors.

9. Is it flame retardant?
Yes—IEC 60332-1-2 compliant.

10. What is the maximum operating temperature?
70°C.

Conclusion

SANS 1507-3 SWA PVC 0.6/1kV cables have earned their reputation as one of South Africa’s most reliable and versatile low-voltage power cables. Their combination of:

• Mechanical strength

• Flame retardance

• Cost-effectiveness

• Ease of installation

• Compliance with South African standards

makes them suitable for almost every LV application—from mining, municipal distribution, and commercial buildings to renewable energy plants.

Whether you are designing a mining MCC, a municipal electrification project, or an industrial installation, SANS 1507-3 remains a trusted, proven, and highly dependable choice in the South African power cable landscape.