Standards & rules
These types of documents describe technical aspects of the products or of the electrical installation and art rules to ensure electrical safety.
It is obvious that the equipment and the material used in an installation should be safe. This means that they should be in accordance with the relevant standards and that they will not endanger the safety of persons and the conservation of property, when they are installed and maintained in a non-defective condition and when they are used in accordance with their intended purpose.
The electrical equipment will also be selected and installed according to the limitations and the environmental conditions of the place to which it can be subjected.
Because of its hazards and its complexity, rules for the erection of an electrical installation were set up and published in national and international standards. Following these rules will help protect persons during the installation, the operation, maintenance and usage of the electrical installation.
Standards are documents that are established by consensus and give the best practices for a process or a product. They are based on the consolidated results of science, technology and experience and are approved by recognized bodies.
Many countries have their own national installation rules / standards, and they are almost always based on the international standard IEC 60364 series.
It is imperative that the electrical installation is properly designed. The best practice therefore is following the rules laid down in the national or international standards.
- The following points, among others, are laid down in the standards:
- The electrical material (cables, protective devices, switches, socket-outlets, light fixtures, etc.): only safe material should be used;
- The protection against electric shock: the correct protective devices must be used;
- The protection against thermal effects (fire, arcs, explosion): the correct measures must be taken;
- The protection against overcurrent, overvoltages and voltage reductions.
- The use of RCD’s should be encouraged, even in the case of the supply being a TN-S system. A 30 mA RCD should protect all the socket-outlet circuits; this also constitutes an additional protection against direct contact in the event of failure of other protective measures against direct contact or in the event of an imprudent act by the user.
A third party should approve the plans, diagrams and calculation notes of the installation before any installation work is carried out.
Initial verification
When a new installation is finished there should be an inspection to verify that all the requirements of the standards have been met.
It is important that a full inspection of the complete installation is carried out. This is to confirm that the electrical equipment and materials:
- are in compliance with the safety requirements of the relevant equipment standards;
- have been correctly selected and erected according to the relevant rules and regulations and to the manufacturer’s instructions, in order that performance is not adversely affected;
- are not visibly damaged so as to impair safety;
- are suitable for the prevailing environmental conditions.
The inspector should also check that the schematic diagrams and the “as installed” drawings are available.
After inspection, the following tests shall be carried out:
- continuity of conductors;
- insulation resistance of the electrical installation;
- protection by SELV, PELV, or by electrical separation;
- automatic disconnection of supply;
- measurement of the resistance of the earth electrode;
- measurement of the fault loop impedance;
- polarity, functional, and operational tests;
- voltage drop.
Periodic inspection
Every existing electrical installation, even it has been initially inspected, should be regularly inspected.
Although is true that electrical installations do not deteriorate quickly, and therefore do not require much maintenance, they do not however retain their original condition: damage, corrosion, degradation of material, degradation of the insulation (the insulation hardens and it can crack), connections become loose, excessive electrical loading, ageing, environmental influences, normal wear and tear, …
Apart from deterioration over the years, the functionality of the electrical installations does not follow the ever-changing needs of its occupants.
Periodic inspections should comprise a detailed examination of the installation. They can be carried out without dismantling, or with partial dismantling the electrical installation.
A periodic inspection will reveal if any of the electrical circuits are overloaded (and thus that more circuits should be provided) and will reveal other potential electrical shock risks and fire hazards in the electrical installation.
It is recommended that electrical installations in homes be thoroughly inspected at least every 10 years. Every 5 years a lighter inspection could be carried out and if it is not possible to inspect all parts of the installation, a sampling should be carried out.
Periodic inspections can also be carried out when a property is going to be let or sold, or after a change of ownership.
Inspection report
At the end of an inspection, a report should be issued. This report can be considered as a certificate of the electrical installation, stating that the installation is safe for use, or a good report can be a “conditio sine qua non” before a certificate of conformity can be issued. This certificate should be limited in time.
The report should give a record of the testing and verifications carried out.
It should be clear what the extent is of the installation that has been inspected: were garages and other buildings that form part of the installation included? The whole installation should be included.
The report should also give a clear indication of the condition of the electrical installation. Al eventual damage, defects, deteriorations of the equipment should be listed in detail.
The report should state clearly if the (existing) installation is still safe to use and what needs to be done to remedy and to bring it back to a safe condition.
If any dangerous situations are discovered, the customer should be immediately warned so that he can take the necessary remediate actions to make the installation safe again. This warning should be in writing, highlighting the severity of the situation and stressing the need for an urgent action.
The report should be kept with the installation. It can later be used when the next inspection takes place, either after for instance 10 years, or when the installation is extended or altered or renewed, or when the house is being sold or rented to someone new.
Inspection for existing installations
As about more than 75% of the dwellings are more than 40 years, in all countries, we could consider the electrical installations as non-compliant, and certainly dangerous for maximum of them.
The aim is to mandatory a type of inspection (diagnostic) for existing electrical installations, in case of sale dwellings or changes of tenant, for common parts of collective dwellings, and for earth connection in common part of the buildings.
The inspection or diagnostic has to certify the conformity of the electrical interior installation of the dwelling.
Inspector
It is clear that the person carrying out an inspection of an electrical installation should be competent to do so. Apart from having a thorough knowledge of the applicable standards, the inspector should have a detailed understanding of safety in electrical installations. He must know how to carry out the tests and be able to work in a safe way with the testing equipment. He must avoid injury to him self and to others.
He must have all the pertinent information about the electrical installation to be able to carry out the inspection in a safe way. He must be in possession of the plans, diagrams and calculation notes of the installation he is to inspect so as to be able to work in a safe way.
He should continuously educate him self to stay ahead of the changing technology.
Electrical contractor or installer
The person carrying out the installation should be well qualified to do so. Persons who are not competent should not be allowed to carry out any electrical work.
This qualification should be documented and the installer should have a proven experience in the work of carrying out electrical installations and a proven knowledge of the rules and regulations of the applicable standard.
Follow-up trainings should be provided to make sure that the installer maintains his skills.
If a homeowner is allowed to undertake the wiring of the electrical installation of his own home, a third party like the Authorities or the Network Distributor, should test to see if he has sufficient knowledge to do so.
Role of utilities
The network distributor can play an important role in obtaining our goal: a safe domestic electrical installation. They can help implement the inspection schemes, put in place by the authorities, by requiring that a positive report or a certificate of the installation be issued before connecting the installation to the public network.
They can refuse to connect an electrical installation to the network as long as there is no such proof of a safe installation (report or certificate) stating that the installation is fully compliant with the applicable standards.
They can carry out random inspections on their customer’s electrical installations and if they come across unsafe installations, they can disconnect them from the public network.
Consumer education
All the citizens should be educated about the right behaviour to avoid the dangers of electricity. They must realise that electricity must be treated with the respect it deserves. They should realise that living with an unsafe electrical installation and using unsafe electrical equipment cab result in an electrical accident
Home users should be encouraged to take responsibility for the maintenance of their electrical systems. They should see the practical reasons for complying rather than simply having to follow yet another regulation.
The need for inspecting the electrical installation should not be considered as a burden, but as something obvious, related to one’s safety.
The owner should understand that an electrical installation does not remain safe and that a good earthing does not necessarily remain in a good condition.
In some countries, special teams visit the households to create awareness on preventive measures against the hazards of electricity.
The owner/user should take every opportunity to have the electrical installation assessed for safety.
Regulation
Although we do not want to live in an over-regulated world, it is be of great help to achieve our goal of safe electrical installations in the homes if the authorities put some regulations in place.
A first regulation would be to require that all electrical installations are build according to recognized standards.
A further regulation could be that all electrical installations have to be inspected before they are put into service and a further regulation would be to impose periodic inspections of the electrical installations.
It is obvious that this list can be extended, depending upon the local situation.
Labelling and certification
It is practically impossible for people to judge upon the suitability and the safety of an electrical component. Therefore it is a good thing to put into place a system of certification of the products and labelling them accordingly.
One must make sure that the labelling is clear and understood by all the parties involved.
Role of manufacturers
Although the first goal of a manufacturer is to make profit, he also has the obligation to produce qualitative and safe products. There are standards that help him to ensure a continuous quality of his production and there are product standards that, when followed, ensure safe and reliable electrical products.
Market surveillance
Unfortunately, there will always be unfair competitors who will try to gain a part of the market by offering second-class and unsafe electrical material. It will normally be the role of the authorities to set up a system of market surveillance to avoid or to stop this from happening.
The knowledge that there is market surveillance can help to deter fraudulent people from bringing unsafe electrical material on the market.