SELECTION AND DESIGN OF LOW VOLTAGE SURGE ARRESTERS

The selection of low voltage surge arrester systems and their specifications create debates, and systems are put under protection with wrong products within the scope of a huge chaos and competition anxiety. As a result, systems are damaged due to sudden overvoltage and lightning impulses. As Yılkomer, we put systems under protection by combining surge arrester selection and design, which we approach with correct survey and correct product recommendation as much as possible, with correct application. In this article, we will proceed step by step on LV Surge Arrester selection and try to enlighten you.

AS YILKOMER, WE USE RAYCAP – ISKRA ZASCITE BRAND PRODUCTS AND PREFER SAFETEC TECHNOLOGY.

As Yılkomer, we carry out the country responsibility of the German company Raycap. Raycap is the company that holds the patent for STRIKESORB technology, which is integrated in series into systems we will launch in the upcoming period, and produces the most powerful surge arresters in this regard. With the company Iskra Zascite it has incorporated, it is also making a serious breakthrough in the panel type product group. It has 2400 different product types in the low voltage surge arrester group with its production facilities located in Germany, USA, Slovenia, and Greece. As Yılkomer, we protect every system at every voltage and current level by combining it with our engineering design with the 2400 different protection products we have.

The concept of technology is extremely important primarily in low voltage surge arrester systems. As Yılkomer, we prefer SAFETEC technologies. Using products with only varistor technology causes the products to be easily damaged. At this point, our only goal is not to allow lightning impulses with safetec technology products where MOV+GDT, i.e., varistors are protected with gas discharge tubes. In addition, this technology, which protects the temperature effect in surge arresters with strong Thermal Control circuits, stands out as the best in its class.

COMPLIANCE WITH STANDARDS IS EXTREMELY IMPORTANT IN LOW VOLTAGE SURGE ARRESTER SYSTEMS

Product and brand selection before design is extremely important. Compliance with international norms is of great importance in this regard. If we look at low voltage surge arrester standards;

While IEC 62305 Ed.2 offers the most general risk analysis and design details on this subject, the IEC 62561 Standard gives us the details of the components used in the products. In terms of components, non-standard products cannot be expected to be successful against lightning impulses. The IEC 61643 Standard is a very important standard that determines the test criteria of Low Voltage Surge Arrester systems. Compliance with the IEC 61643 norm should be noted in the product tests received.

IEC 61643-11 ensures the determination of basic surge arrester electrical parameters. We indicate the important ones of these simple parameters below;

• Uc (Maximum Continuous Operating Voltage)
• Test Class: I, II, III
• In (15 shots)
• Imax (8/20)
• Iimp (10/350)
• SCCR (Short Circuit Current Rating) kA
• External/Internal disconnector
• TOV

Based on the IEC 61643-11 standard, manufacturers receive test certificates from independent organizations such as VDE, KEMA, TUV. RAYCAP products comply with all relevant standards.

IF THE SUBJECT IS LIGHTNING, TYPE 1 10/350ms IMPULSE SELECTION SHOULD BE BASED ON

After choosing the right product, brand, and technology, we can move on to our design steps. The lightning impulse has a 10/350ms curve. If the subject is lightning protection, the surge arrester we buy must definitely have a test value in the 10/350ms test curve. The product tested at 10/350ms against lightning impulse is called CLASS B SURGE ARRESTER or TYPE 1, CLASS 1 surge arrester. CLASS B Surge Arrester must be used in the main panel, in open field environments, in areas directly exposed to lightning such as solar power plants, and at building entry points. In buildings with external lightning protection systems such as Lightning Rods (Paratoner) or Faraday Cages, CLASS B SURGE ARRESTER MUST be used in main panels, and in floor panels next to the main panel of structures where the external lightning protection system descends uninsulated. In Type 1 surge arrester products, the protection level varies in the 10/350ms curve; there are many products here from 5kA protection value to 150kA value. Surge arrester selection starts here. As a result of risk analysis, the protection level should be selected according to the regional risk. A product with a protection value of 12.5kA remains helpless at a point where 100kA comes. The 10/350ms curve value is included as Iimp in datasheets. Surge arrester can be selected by checking the Iimp value. Generally, the concept of CLASS B 100KA surge arrester is settled in our country. However, we do not have to use this product at every point; we can select the right products by making risk analysis design.

TYPE 2 8/20ms IS IMPORTANT AGAINST GRID IMPULSES AND SWITCHING ELEMENTS

We witness that Type 2 Surge Arresters are used in main panels in low voltage surge arrester systems, and the facility is put at great risk. TYPE 2, CLASS C SURGE ARRESTERS only protect against grid impulses; they do not provide protection against lightning impulses. Products called TYPE 2, CLASS C SURGE ARRESTER, CLASS 2 are tested according to the 8/20ms curve. Sudden voltage surges, harmonics, switching impulses are dampened with this product. However, if lightning comes to this product, the product explodes. Therefore, when choosing a product, CLASS C SURGE ARRESTER should be preferred in sub-panels and points that will not be directly exposed to lightning. The characteristic of Class C surge arresters is Imax. Generally, 40 kiloampere CLASS C Surge Arresters are used in our country.

IF WE WANT TO PROTECT AGAINST BOTH LIGHTNING AND GRID IMPULSE, WE CAN CHOOSE COMBINED PRODUCTS

Combined products provide protection against both lightning and grid impulses.

Combined surge arresters named as Type 1+2+3 LV Surge Arrester, Type 1+2 LV Surge Arrester, Class B+C LV Surge Arrester provide protection against both lightning and grid impulses. CLASS B+C SURGE ARRESTER should be used in all panels located in the open field. Class B+C surge arresters also vary according to protection values. In this category, Type 1+2+3 100kA Protected products provide great advantage especially in residential protections such as villas.

WE CANNOT PROTECT THE ENTIRE FACILITY BY PROTECTING ONLY ENERGY LINES. CLASS D SURGE ARRESTERS ARE OF GREAT IMPORTANCE AT THIS POINT

Class D surge arresters in surge arrester selection are generally skipped and not included in the design; project companies do not touch upon this subject much either. However, data, coaxial, and communication lines are as important as energy lines. Data line protection, Cat line lightning protection, POE lightning protection products, Weak current 24v, 48v surge arresters, coaxial surge arrester line protections, RS232, 485 Communication module surge arresters are of great importance in this category. For example, in a camera protection system, cat line surge arrester is of great importance for the lightning protection of cameras and switches, or TELECOM LINE LIGHTNING PROTECTION Surge Arresters are very important against impulses coming from telecom lines. Therefore, we have to give special importance to TYPE 3, CLASS D, CLASS 3 Surge Arresters. If we do not give this importance, our entire facility can be damaged in a short time.

A SAMPLE CAMERA PROTECTION SYSTEM

If we share a sample design on Lightning Protection of Cameras, you can see the protection of energy, data, and coaxial lines;

In conclusion, lightning protection of systems requires expertise, and products need to be selected according to system features in different systems. Lightning impulse definitely damages our systems significantly, and at this point, low voltage surge arrester selection and design, and the application of surge arresters are extremely important. You can apply via the Yılkomer free survey and support line and ask us to suggest the most correct solution for your facility.

Don’t forget Yılkomer ‘Protects Your Values’.