What is an electrical wiring harness?
An electrical wiring harness, also known as an electrical spider system, is a solution designed to make the installation and distribution of electrical wiring easier. The harness comes as a pre-wiring kit that you can install yourself to supply electricity throughout an individual home. In practical terms, all the wires needed for your equipment (switches, electrical sockets, lighting, washing machine, dishwasher, television, etc.) are grouped together and pre-wired in conduits in advance according to their location in the home. All the ICTA conduits are grouped towards a junction box, which is connected to the electrical panel via the Housing Technical Duct (GTL). The conduits are then deployed to the corresponding room or rooms. Depending on the size of your home, you may need several electrical wiring harnesses.
It takes its name from its appearance, which resembles an octopus, with the box representing the body and the conduits the legs or tentacles. To create the electrical wiring harnesses, a design office produces an electrical routing plan for the installation. This makes it easy to determine the lengths of conduit, the number and lengths of the corresponding wires, the number of junction boxes, etc. To make identification and installation easier, each conduit is coded on the plan and then fitted with a label during production.
The advantages of installing an electrical wiring harness
A simplified and accessible electrical installation
Specially designed to make installation easier, the electrical wiring harness is easy to install thanks to the electrical diagram supplied and the various markings on the electrical accessories. Overall, the most complicated work has already been done upstream. Everything is already determined by the design office and the conduits are already pre-wired using a Mecaspin MS03-type pre-wiring machine, which reduces the risk of errors. Inserting wires into conduits is indeed a tedious and time-consuming stage, even for specialist installers.
A major time saving on your worksite
The easier it is, the more time you save on site. Allow 2–3 days to complete the installation, whereas an installation without an electrical wiring harness can take an electrician up to 3 times longer.
Reduce the cost of your electrical installation
The major advantage of installing an electrical wiring harness is that the cost is halved. This solution will therefore be considerably more economical if you are prepared to carry out the work yourself. You can complete the installation without prior electrical knowledge. What is more, when buying from an electrical wiring harness manufacturer, you will pay less for your electrical equipment thanks to the attractive prices they can offer because of their substantial purchasing volumes.
Reduce the risk of errors
If you decide to install your electrical wiring harness yourself, you will not have to worry about making mistakes. Have I chosen the right conduit diameter? Do I have the right number of electrical wires? Do I have the right length? All these tasks are carried out by a professional in the factory using a pre-wiring machine. They will also provide you with the pre-wired electrical panel, which is certainly one of the most tedious tasks to complete yourself. You can also forget about accidentally omitting equipment when purchasing, as everything is supplied in the ready-to-install electrical wiring harness kit.
How much does a custom electrical wiring harness kit cost?
The cost of your wiring harness kit can vary considerably depending on your requirements. You need to take into account the floor area of your home, the number of rooms, your requirements (power sockets, switches, etc.) and your electrical equipment (heating, mechanical ventilation, home automation, air conditioning, heat pump, etc.).
For a 120 m² house, the estimated cost is around €4,500 to €6,000, or approximately €50/m². An electrician will charge around €9,000 for the same service including installation.
Compliance with the NF C 15-100 standard
The electrical wiring harness, like your entire installation, must meet the requirements of the NF C 15-100 standard. This standard ensures the compliance and safety of your electrical installation, whether for a detached house or a renovation/extension. It covers information such as the number and location of sockets, switches, lighting points, etc.
Professionals in the sector undertake to provide you with a wiring harness kit that fully complies with the standard and regulations. It is therefore important to use a qualified electrical wiring harness manufacturer for this type of work. If you have questions about the connection requirements for your electrical installation in relation to the standard, they will be able to answer them.
If you would like more information, we invite you to read our article about the NF C 15-100 standard.
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Can you make an electrical wiring harness kit yourself?
It is possible, but you will need some electrical skills and, as mentioned above, knowledge of the NF C 15-100 standard and its equipment and technical requirements. You must not forget any equipment and need to provide enough ICTA conduit, electrical wires, junction boxes, flush-mounting boxes, DCL boxes, equipment for pre-wiring, etc. You will also need to be vigilant about installation and connection errors, which can be costly.
You should also bear in mind that, for a new-build home, your installation will be inspected and must obtain Consuel certification. Without this certificate, you will not be able to connect to the electricity network and energise your installation.
Where did the electrical wiring harness come from?
Invented after the Second World War in 1944 by Arthur William Marshall Hartley, the electrical wiring harness originated in Great Britain under the name Project OCTOPUS. The invention was used particularly for reconstructing buildings destroyed during the war.
In 1946, the project arrived in France in the form of invention patent No. 912612, described as an “improvement to electrical wire installations in buildings”.
In 1947, a French company called OCTOPUS began using the process. In 1949, the CSTB (Scientific and Technical Centre for Building) granted approval for the new materials and non-traditional construction processes. The electrical wiring harness then became a standard installation method for electrical companies.
As you will have understood, if you can install it yourself, choosing a custom electrical wiring harness kit for your home electrical installation is very worthwhile. Whether in terms of cost, practicality or installation speed, you stand to benefit. For the production of the kit, if you are not an electrical expert, it is better to use an electrical wiring harness manufacturer who will support and guide you through the project and ensure compliance with the standards.
