Electric Cables
Electric Cables – What is Legal
We get a lot of questions about which electric cables are legal and how they must be installed. So here is a brief rundown of the different types of legal cabling available and the way an installation could be done. There are various accepted methods and we illustrate a general one here. When a builder has to wire a home, he will first lay conduits, which are plastic or metal pipes fixed in place above the plastic damp-proof underlay and the steel reinforcing. (See the picture above.)
These pipes are laid out according to the house plans and extend upwards from the floor and will be built into the walls later when the bricklayers start their work. The concrete for the floors will then be placed, and the conduits will run within the floor slab. From there they can be chased, or cut, into the walls so that they can be routed to various outlet points where plug points and lights are required.
Surfix and Flat-Twin-and-Earth cables
The electrician will later pull the wires through these tubes. There are classes of cable that do not need to be encased in conduit and can be chased into, and laid directly under the plaster. Two examples of these are Surfix and Flat-Twin-and-Earth cables. A full specification can be found in the Aberdare brochure below. When the roof is on and waterproof the cables can also be laid in the roof space for overhead lighting and other fittings.
Be Guided by What the Law Says about Electricity and Electric Cables
By law, a fully qualified and registered electrician must be responsible for the wiring. It is a good idea for all homeowners to familiarise themselves with and be able to identify, different types of cable and flex to ensure that all materials used in the installation are up to standard (literally – they need to meet the relevant South African National Standard). The National Building Regulations and Building Standards Act does not cover electricity and nor does SANS 10400. Electricians must comply with SANS 10142: The Wiring of Premises.
Insulation Material
Depending on the class of cable the non-conductive insulation material around the wires inside cables and flex are different colours to make it easy to identify them. Green, or green and yellow, is the earth; live wires are brown or red; and neutral is either light blue or black. Once the wiring in a building is complete the entire system must be checked by an accredited person (from Eskom or the municipality/ local authority) who will issue a certificate of compliance.
A Registered Professional Is Needed When Installing Electric Cables in the Home
When it comes to electrical installations, it is always recommended to use a registered professional. Electrical work in the home can be complex and potentially dangerous if not done properly, which is why it is essential to hire a qualified electrician to install electric cables. In this article, we will discuss why a registered professional is needed when installing electric cables in the home.
Safety
The primary reason to hire a registered professional for electrical installations is safety. Electricity can be dangerous if not handled correctly, and a licensed electrician has the knowledge and expertise to install electric cables safely. They understand the correct procedures for grounding and bonding, and they know how to work with live wires without putting themselves or anyone else in danger. They also have the proper tools and equipment to do the job safely and efficiently, reducing the risk of accidents or injuries.
Code Compliance
Another reason to hire a registered professional when installing electric cables in the home is to ensure compliance with electrical codes and regulations. These codes are designed to ensure the safety of the electrical system and prevent hazards such as electrical shocks, fires, and other dangerous situations. A licensed electrician has a thorough understanding of these codes and regulations and will install electric cables in compliance with them. This ensures that the electrical system is safe and up to code, reducing the risk of accidents and injuries.
Quality Workmanship
A registered professional electrician has the knowledge and experience to do the job right the first time. They understand the correct methods and techniques for installing electric cables, and they have the necessary tools and equipment to do the job correctly. This results in high-quality workmanship that is reliable and long-lasting, reducing the risk of future electrical problems or failures.
Insurance
Another reason to hire a registered professional electrician when installing electric cables is insurance. If an unlicensed person does electrical work in your home and something goes wrong, you may not be covered by your insurance policy. This means that any damage or injuries resulting from the electrical work will be your responsibility. However, if a licensed electrician does the work, they are typically insured, and any damages or injuries resulting from the work will be covered by their insurance policy.
Warranty
Finally, a registered professional electrician typically offers a warranty for their work. This means that if anything goes wrong with the electrical installation within a certain period of time, they will come back and fix it at no extra cost. This provides peace of mind and ensures that the electrical work is done correctly the first time. In conclusion, when it comes to electrical installations, it is always best to hire a registered professional. They have the knowledge, expertise, and experience to install electric cables safely and correctly, ensuring compliance with electrical codes and regulations. They also provide quality workmanship, insurance, and a warranty, giving you peace of mind and protecting you from potential hazards and liabilities.
Aberdare Cables have an excellent brochure (see below) that should help to identify the various cables associated with the electrical installation in a house.
[Note that we have no affiliation with this company and reference to their brochure does not imply any particular recommendation.]
Hi Klasie, According to SANS 10142-1 (The Wiring Code of South Africa), electrical wiring in the roof of a house must be in conduit unless it meets specific conditions. Here’s what you need to know:
1. Wiring Requirements in a Roof Space
Conduit is required for most fixed wiring to protect cables from mechanical damage, rodents, and heat exposure.
Flexible cables (like twin and earth or surfix) may be used without conduit if they are secured properly and rated for open installation.
Bare or exposed wiring is not allowed — all cables must be properly insulated and installed to prevent electrical hazards.
2. When Conduit is Mandatory
If the wiring is subject to mechanical damage (e.g., near ceiling boards, accessible spaces, or crossing beams).
If the cables are low-quality or not designed for open-air installation.
If required by the local authority or an electrician’s safety assessment.
3. What You Should Do
Consult a Qualified Electrician to ensure compliance with SANS 10142-1.
Check the Local Municipality’s Regulations, as some areas may have stricter installation rules.
Use Properly Rated Cables if opting for flexible wiring without conduit.
Hi Patrick, Regulations for Running Electricity from a Main House to a Granny Flat in South Africa
When running an electrical cable between the main house and a new granny flat, it’s essential to follow the South African National Standards (SANS 10142-1), which regulates electrical installations to ensure safety and compliance.
Key Regulations and Guidelines:
Cable Depth for Underground Installation
The minimum depth for burying an electrical cable underground is 500mm (50cm) below the surface.
If the cable is to be laid under a driveway or area with vehicular traffic, the depth must be increased to 1,000mm (1 meter) for added protection.
Cable Protection
The cable must be a SWAC (Steel Wire Armored Cable) or similar type suitable for underground use.
Lay the cable on a bed of sand (about 100mm deep) to protect it from sharp objects.
Once the cable is laid, cover it with another 100mm of sand before filling the trench with soil.
Install a warning tape approximately 300mm above the cable to alert future diggers of its presence.
Distance from Other Services
If other services like water pipes, sewer pipes, or gas lines are present in the same trench, the electrical cable must be separated by at least 300mm horizontally and vertically.
Cable Type
Use an armored cable or conduit to prevent accidental damage.
The cable size must be calculated based on the load requirements of the granny flat (e.g., lights, plugs, appliances). Typically, a 6mm² or 10mm² cable may be required for this purpose, but an electrician should determine the correct size.
Circuit Protection
The cable must originate from the distribution board in the main house, with its own dedicated circuit breaker for protection.
Install an earth leakage unit in the granny flat’s sub-distribution board for additional safety.
Inspection and Compliance
All electrical work must be done by a qualified electrician who is registered with the Department of Labour.
A Certificate of Compliance (CoC) must be issued upon completion of the installation to certify that it meets SANS 10142-1 standards.
Important Considerations:
Trench Safety: Ensure the trench is dug safely, particularly if it exceeds 500mm in depth, to avoid collapses.
Permits: Check with your local municipality if additional permits are required for the electrical work.
Future Maintenance: To make future repairs easier, consider marking the route of the cable on a site plan.
Steps to Follow:
Engage a registered electrician to assess the load requirements and determine the appropriate cable size.
Dig a trench at least 500mm deep (or 1m under driveways) along the planned route.
Lay a sand bed, place the cable, cover with sand, and lay warning tape above the cable.
Backfill the trench with soil.
Install all required electrical protection (e.g., circuit breakers, earth leakage units) in compliance with SANS 10142-1.
Get the installation inspected and obtain a Certificate of Compliance.
By adhering to these regulations and hiring a qualified electrician, you can ensure that the electrical connection between the main house and the granny flat is safe, legal, and durable.
Hi Abubaker, Chasing in Building Blocks for Electrical Installations in South Africa
In South Africa, chasing into building blocks or walls for electrical installations is allowed, but it must comply with specific standards and guidelines outlined in the South African National Standards (SANS 10142-1), which governs electrical installations, and SANS 10400 (National Building Regulations).
Key Points to Consider:
Structural Integrity
Chasing into load-bearing walls or structural components must be done with extreme caution. Deep or wide chasing can compromise the strength of the wall. Always consult a structural engineer if there is any doubt.
Horizontal chasing in walls should be minimized as it poses a higher risk to the structural integrity compared to vertical chasing.
Avoid chasing near corners or at critical structural points such as beams or lintels.
Depth and Width of Chasing
The depth and width of the chase must be within limits that do not weaken the wall. As a general guideline, the depth of the chase should not exceed one-third of the thickness of the wall.
SANS 10142-1 Electrical Standards
All electrical work must comply with SANS 10142-1, which requires electrical installations to be safe, durable, and properly concealed. Conduits must be installed in the chases to protect the wiring from damage and ensure compliance.
The conduits should be securely fixed in place, and the chase must be properly plastered to prevent future issues, such as cracking.
National Building Regulations (SANS 10400)
SANS 10400 specifies that building work must be done in a way that does not weaken or compromise the safety of the structure. This includes making alterations to walls for electrical installations.
Use of Conduits
Electrical wiring should never be directly embedded into the wall without proper conduits or trunking. This is to:
Protect the wiring from damage.
Allow for future maintenance or replacements.
Ensure compliance with electrical safety standards.
Local Regulations and Inspections
Some municipalities may have additional regulations regarding wall chasing. It is always advisable to confirm with your local building inspector or electrical inspector.
Work should be inspected by a certified electrician, and a Certificate of Compliance (CoC) must be issued upon completion.
Practical Tips for Compliance:
Plan the Layout: Minimize the number and length of chases where possible by planning the electrical layout carefully.
Hire a Qualified Electrician: Ensure all work is done by a qualified electrician who is familiar with SANS 10142-1 and local regulations.
Patch Properly: Once the wiring and conduits are installed, the chase must be filled with a suitable plaster mix to restore the wall’s finish and strength.
Avoid Overloading Walls: In cases where extensive chasing is required, consider using surface-mounted conduits or trunking as an alternative.
When Not to Chase:
Hollow blocks or thin walls: Chasing into hollow concrete blocks or very thin walls can severely weaken the structure. In such cases, alternative methods (e.g., surface-mounted conduits) should be used.
Structural Walls: Avoid chasing into walls that are critical to the building’s stability without professional advice.
By following these guidelines and consulting a professional where necessary, you can ensure the electrical installation is safe, legal, and compliant with South African standards.
no you must have some sort of protection, warning tape etc, best is to place it in conduit, be sure to check your load
it is not legal, each addition should have a new feeder cable installed as the existing feeder cables are be
designed for a specific load, and should not be used for an extension, of any sort.
SABS is the answer, it is legal, as long as you get the result requested
no, you must do a proper load flow, staring from the flat, make sure what exact load are reuired, and do a load flow from there, also a armor cable must be used, check your volt drop and amps regarding buried in soil, air, or ducted system, then check your feeder cable and ensure that it can handle the load together with the breaker
no, check youe SABS i my years it was a max of 1,5 meter, a plumber wil not know this, but and electrician, it have changed in the years as you can have a cupboard dividing the exact length, and also some water appliances require you a connection within 30 cm from the the unit,
The wiring in a roof of a house, must that be in conduite or will the flex kind off kable enought?
Are you allowed to chase in building blocks?
(Electrical)
what are the regulations in running electricity from a main house to a new tech granny flat being built how deep must the cable be buried to cover the 15 meters between them
Only a qualified, registered electrician can do this work! If you do it the connection will be illegal.
This is not specified in the Building Regs