Once, during a storm, we would quickly disconnect our most valuable home appliances from the power source. Everyone knew that they could be irreversibly damaged, although most of us had no idea why. To this day, many people, seeing lightning in the sky, disconnect their computer, washing machine or TV from the power supply, although in modern buildings, electrical devices are usually well protected. Effective protection of the electrical installation and devices connected to it is provided by, among others, surge arresters. What is a surge arrester and how does it work? Which surge arrester should you choose for the planned network layout? Where and how to connect it? We answer!
Check surge arresters at the Onninen wholesaler
What is a surge arrester?
A surge arrester is a device used to protect electrical devices against transient overvoltages, i.e. against a sudden, short-term increase in supply voltage. The arrester limits the duration and frequency of the follow current. By blocking with inductive coils or by short-circuit current, it effectively reduces the voltage to an acceptable, safe level. Standard surge arresters consist of a base and a replaceable insert with a spark gap (class B) or a varistor (class C). A spark gap surge arrester is the simplest and cheapest variant. The phase conductor and the protective PE conductor are connected to the surge arrester.
Why are surge arresters used?
Surge arresters of all types are used to reduce surges. Surge surges can occur in various situations, such as during a storm, when lightning strikes an overhead line, or when switching on/off an unloaded overhead line. Surge surges can damage insulation and destroy other elements of the electrical network. Modern RTV/AGD equipment is particularly sensitive to surges. Although complete physical destruction due to surges rarely occurs in practice, interruption of work, memory reset, or data transmission problems are already very real threats. No surge protection solution will give us a 100% guarantee of the safety of home appliances. However, the risk of threats can be effectively minimized. Is it enough to connect a surge arrester? Not necessarily...
When is it worth using surge arresters?
Guidelines on the use of surge arresters in electrical installations are regulated by various legal acts and Polish Standards, in particular the Regulation of the Minister of Infrastructure of 12 April 2002 on the technical requirements that buildings and their location should meet (Journal of Laws of 2002, No. 75, item 690, as amended) and the PN-IEC 60364-4-443 standard, concerning surge protection in electrical installations. In accordance with § 183. 1. of the aforementioned regulation, surge protection devices should be used in electrical installations .
However, the legislator did not include a detailed definition of such devices or specific requirements in the legal act. Individual recommendations and guidelines for the use of surge arresters are often issued by manufacturers of electrical devices and insurance companies. Installing a surge arrester may even be a condition for the insurer, seller or manufacturer to accept liability in the event of damage caused by surge.
If you care about safety and do not want to constantly worry about the voltage supplied to expensive home appliances, it is worth investing in surge arresters - necessarily high-class, with parameters confirmed by tests/certificates. It is best to plan the selection of arresters and their location at the building design stage, and entrust the installation to an experienced electrician.
It is necessary to mention situations in which surge protection is not required because the anticipated costs of preventing the hazards would most likely be higher than the benefits. Detailed information on this subject is provided in one of the chapters of the PN-IEC 60364-4-443 standard.
Check surge arresters at the Onninen wholesaler
Which surge arrester should I choose for my apartment?
There is no clear answer to this question, because surge arresters must be adapted to the requirements of the devices in question and the specifics of a given electrical installation, in particular its layout. It is not indifferent whether a 3+0 or 3+1 surge arrester is used in a TN-C system. Therefore, the installation design, taking into account each arrester and protective conductor cross-section, should be performed by a qualified electrician.
Arresters designed for low voltage areas are divided into types/classes. It is recommended to install protectors of individual classes/types in buildings in a cascade manner, i.e. gradually reduce the voltage level.
-
A type 1 (class B) surge arrester , commonly called a lightning arrester, provides home electronic equipment with protection against surges caused by lightning striking a power line. It limits the voltage impulse to a value below 4 kV. Type 1 surge arresters are spark gap arresters. The protective element in them is a spark gap. - A type 2 (class C) arrester , commonly called a surge arrester, provides protection for installations against sudden voltage surges (commutation surges) of low values - from 1 to 1.5 kV. Its design includes a varistor.
- The type 3 (class D) arrester provides protection for specific, most sensitive electrical equipment. It can be mounted in the switchboard, behind the socket in the electrical box or in the device itself.
On the market, including of course in our wholesale store, you will also find hybrid models, such as the B+C surge arrester , which is a combination of B C protectors. It is used in electrical installations that may be directly exposed to atmospheric discharges.
Where to connect the surge arrester?
If you are looking for specific, uniform guidelines on where or how to connect a surge arrester, then... you will not find them, because the aforementioned standard contains only general information on the installation of surge arresters in building installations. They are most often installed in the main switchboard as close to the connector as possible. Type 3 (class D) surge arresters can, instead of in the switchboard, be located behind the socket in an electrical box or directly in the protected devices.
Just inserting a surge arrester into the switchboard is not enough. The key factor in the effectiveness of the implemented surge protection is the skills of the electrician and whether he bases it on the current state of knowledge or on practices from 30 years ago.
Surge arresters at the Onninen wholesaler
In the Onninen electrical wholesaler, a wide range of surge arresters awaits business and individual customers - standard and less popular types. In our offer you will find a DC surge arrester , commonly used in renewable energy and electric vehicles. You can choose from selected solutions from renowned manufacturers and brands. You can buy from us, among others:
- Dehn surge arrester ,
- Hager surge arrester ,
- Eaton surge arrester ,
- Schneider surge arrester ,
- Legrand surge arrester ,
as well as various accessories: cables, terminals, lightning protection barriers, grounding connection blocks, protective devices and many others.
Remember that you can count on the professional support of Onninen experts when purchasing the right products. We will help you choose safe and effective surge arresters and all the accessories necessary for the project, including protective cables with the right cross-sections. Write, call or visit us in person at 1 of 36 branches.