When making a decision about construction or renovation of a residential building, workshop or industrial hall, we need to ensure proper functioning of various networks and systems. Beside water, heating and ventilation systems, among the most important ones is an electric power system, which supplies and distributes electric power that is essential for functioning of many devices. Learn how to check it properly.
From this article you will find out:
- How an electric power system is constructed;
- What are the types of electric power systems;
- What is special about residential electric power systems;
- What are the ways to check electric power systems;
- How to avoid mistakes in electric power systems.
How is an electric power system constructed?
An electric power system is a low voltage distribution system (alternating current of 1000 volts and direct current of 1500 volts). In the context of power systems, we often mention the wiring, but it is important to remember that it also includes other devices that are plugged into it. All kinds of audio-video equipment and other household devices as well as computers are also a part of the electric power system.
Almost every electric power system consists of the same elements, and any possible differences result from its purpose. The important issue is how a given building will be powered, which is often determined by the power distribution company. Industrial facilities are often situated in large complexes of buildings, which is why they are powered by a few distribution boards located in various parts of such complexes. Detached houses have one distribution board and one electric meter each, usually placed next to one another, thanks to which reading the meter and providing a quick help (if, for example, we overload the system) is much easier.
Other important components are power cables which consist of an electrical conductor, most frequently made of copper, and insulation, which should be selected depending on the working conditions of a given electric power system. It is often the case that the cables which are suitable for residential electric power systems will not be sufficient in farm or industrial buildings.
Wiring in electric power systems
One big problem related to the durability of electric power systems are environmental conditions such as humidity, which can lead to short-circuits or other malfunctions. Therefore, it is very important to choose proper wiring to a specific building or even a single room. In detached houses, there are also places with increased humidity levels, for example bathrooms. Here, we recommend HELUKABEL 371359 cables with waterproof PVC insulation.
Apart from that, cables are characterized by a conductor diameter, whose different values are selected depending on the rated voltage or current-carrying capacity. Electric power system cables with a capacity of up to 14 amps are usually 1.5 mm2 in diameter. For 19-amp systems, the cables are 2.5 mm2 will be suitable. Naturally, a lot depends on the material from which the conductor was made – the figures above apply to copper wires.
Types of electric power systems
When talking about the types of electric power systems we can discuss various ways of categorizing such systems, for example, depending on the manner of installation, type of electric power receivers or a place where a given system is installed.
Location of an electric power system
An important factor in selection of an electric power system is the function of the building in which it will be installed. In this respect, we distinguish between:
Industrial electric power systems, which we can see in different kinds of halls, factories and warehouses. They are characterized by many distribution boards and are exposed to adverse environmental conditions, such as lowered temperature (cold rooms) or increased humidity levels. In such places, the devices usually work under high voltages and with high amperages – that is why individual elements of the power system must be adequately selected to match high electrical loads.
Residential electric power systems, which consist of every power system installed in buildings which are regularly inhabited. They usually have one distribution board, and do not require such durable components (for example conductors).
Types of receivers
Depending on the amount of power needed by a given device, we can use:
lighting systems, which consist of all kinds of lamps and other devices that are sources of light,
connection systems, which supply energy to devices that require a high level of power, for example: industrial machines or water heaters.
Residential electric power systems
Most of users deal with residential electric power systems on a daily basis. In our houses, there are increasingly many devices requiring electric power, which is why it is important to prepare the right number of sockets, and arrange them according to individual needs. The method of installation is equally important, and it can be divided into three types:
- Concealed wiring installation mainly used in brick detached houses. Before installation, chases are made in the walls, in which protective cable ducts are then placed. When the plaster is dry, we can pull the cables through the ducts and after that mount the receivers. This manner of installation effectively protects the cables against damage, but it is time-consuming and replacement of cables is rather complicated.
Flush-mounted installation where cables are laid before the plaster layer (minimum 5 mm). Cables are mounted directly to the raw wall surface with the use of nails, clips and wires or, nowadays increasingly often, they are simply fixed with self-adhesive cable holders such as KSS WIRING AP-0810. It is a simple way of installation, however, in the case of malfunction or alterations, it will be necessary to remove the plaster.
Surface-mounted installation is widely applied everywhere where looks are not important, e.g. in all sorts of humid spaces, such as basements, utility rooms or laundries, but also outside buildings. Before the installation of cables, we need to equip ourselves with pegs or nails which are mounted onto plastered walls. Only then can we attach the cables.
It is worth mentioning that in the process of designing an electric power system both connectors and lighting systems should be grouped in circuits, and every such circuit should be separately connected. This way, we avoid situations when, as a result of malfunction of one of the parts, we do not have power in the whole apartment. An optimal number of circuits is calculated depending on the surface area of the house, but obviously more circuits can be installed for future use.
Checking electric power systems
There are several reasons why we check the quality or proper operation of electric power systems. In the course of time, cables wear out, which may lead to malfunction or power outages. This is why it is important to check every once in a while if the supplied voltage is on an appropriate level, depending on the character of work of a given system. The more the system is exposed to external elements, the more often such tests should be conducted.
It is done by various testers, i.e. devices for measuring parameters such as the quality of power (including power from three-phase systems used in residential systems), insulation or earth resistance or circuit continuity. An example of such multifunctional tester is KYORITSU KEW6010B.
Measurement is carried out in a few steps:
Connect measuring probes (if needed) to the matching sockets of the meter.
Position the function/range switch in a desired position, or in such a way that it is situated within the right range. If the value of the measured signal is unknown, pick the highest measurement range.
Clutch the other end of the probe to the point of measurement, attach current clamps and push the right button or put the device close to it (only in the case of contactless measurements) in order to check the parameter.
The tester will inform you if the results of the measurement deviate from the norm. In that case, the malfunction should be fixed and the measurement should be repeated for the purpose of verification.
With such devices, even less experienced users can check if the power systems in their houses work properly, and those more experienced (electricians) use them in their everyday work. Among the latter, clamp meters – which are smaller, more ergonomic and easier to use – become more and more popular. FLUKE 1630-2 FC is worth recommending here.
One of the most frequent mistakes in the process of designing electric power systems is connecting all of the electrical connections (sockets) and sources of light to one circuit. There can be as many as 10 or 20 connections or light sources within one circuit, however, it is better to break it down into smaller ones. In case of malfunction, there will be no power only in some of the devices.
Another big problem is connecting all power receivers to one phase, when in fact we have three of them available – residential electric power systems are powered by three-phase voltage.
|CLEAN-CABLE4X1.50||Wire; Clean Cable; stranded; Cu; 4x1,5mm2; cross-linked polyethylene|
|AP-0810||Self-adhesive cable holder; 7.9÷10.3mm; polyamide; black; UL94V-2|
|KEW6010B||Appliance meter; LCD 3.5 digit (1999); IP40|
|FLK-1630-2FC||Ground clamp loop tester; LCD (9999)|