Selection and sizing of the electrical equipment in a building

• 30 March 2017
• Local News
• 8565 Views

Proper design, selection, and installation of electrical systems for buildings are crucial to using electricity safely and efficiently. Inferior wiring and equipment or wrong equipment selection cause hazardous conditions for humans and buildings, and often result in increased maintenance costs and greater risk of fire.

The mere fact that an electrical system “works” doesn\’t mean it\’s safe or will fail safe.

Indeed, faults in the electrical wiring systems of buildings account for the majority of fires and in some cases fatal electric shock accidents.

Every year in Cambodia more than 600 homes are consumed, dozens of people die or are severely injured, and many people lose their work means or assets such as cars, tractors, warehouses, etc.

According to recent statistics, about half (47 percent) of these fires result from electrical malfunctions. This is largely due to the absence of norms and standards in Cambodia when it comes to electricity.

Many products (circuit breakers, switches, sockets, multi-outlets extensions) sold on the local market would not be accepted in other countries due to their complete absence of safety.

Equally too often, the design and planning of the installation is not done according to international safety standards, and there is no consideration of potential future evolutions of the building.

Design & equipment selection

It is important to remember that design and selection should be done by a proper electrical engineer, who knows the necessary sizing and equipment for each location. Improper design like inferior wiring can lead to overheating.

Overheating occurs when installations are overloaded, a classic example being the use of multi-adaptors or multi-socket extension leads. These are not inherently dangerous as they can be used quite safely to connect several low power items such as TV, fans, etc. but they do facilitate overloading. If too many appliances are connected to an electrical circuit, excessive heat will be generated in the copper conductors which can lead to a breakdown of the insulation and a short circuit.

Especially in Cambodia, where most adaptors and multi-socket extensions are not protected against overheating this can become a big issue. To tackle this problem, Legrand has recently introduced fuse-protected multi-socket extensions which will protect you efficiently in case of overheating.

Incorrect equipment selection

Effects of incorrect selections can range from the slight discomfort of an outdoor socket broken with the rain (if a weatherproof socket has not been installed) to much bigger problems like electrocutions, fires, and sometimes death. A typical example of incorrect and dramatically dangerous equipment selection is the equipment next to a swimming pool. Too many cases happened when standard (non-weatherproof) switches and sockets had been installed nearby, and no proper (or insufficient) earth bonding had been made which transformed the swimming pool (water being a great conductor) in a deadly area leading to several death cases.

Installation, Inspection, Testing and Maintenance

Beyond the design and equipment selection, the installation, inspection, testing and maintenance of new or altered electrical systems should only be carried out by a competent qualified electrical contractor.

If you are seeking for professional contractors, Legrand Cambodia team can recommend a few which are recognised for their professional work in the Kingdom.

The electrical installation must be installed in accordance with the IEC 60364-1, which is the international standard covering all low voltage electrical installations.

It covers all fundamental principles, protection for safety, selection and installation of electrical equipment, as well as the requirements for special installation or locations, such as a medical facilities or swimming pools for instance.

Following IEC 60364-1 standard will come to an additional cost, but must be seen as a necessary investment as it is very affordable compared to the price of losing your building to a fire, or losing a relative because insufficient care has been taken with the electrical system.

In a market overrun by bad quality products, looking for a recognised brand name like Legrand, which manufactures 100 percent of its products according to international standards, is the best solution to protect your building and relatives 