3 Fundamental Problems Faced by Facilities Around Telecom Towers Against Lightning

Telecom towers were traditionally located in protected areas and at certain distances from cities; however, today network densification is carried out to provide high data speeds, and therefore towers are positioned within cities and close to residential areas. Small cells, mini cabinets, and small street cabinets—important components of the infrastructure—are located right at the center of densely populated metropolises. A lightning strike on or near the distributors located here can cause the entire telecom infrastructure to be taken out of service and may damage surrounding systems and structures. In fact, a telecom tower close to a city center is in a Risk 1 condition in terms of attracting lightning and must protect both itself and its surroundings against lightning.

A telecom distribution system or base station damaged by lightning will prevent nearby users from accessing services, and in this highly competitive sector, this may result in serious customer loss. In addition, fires and physical injuries caused by lightning strikes may become an issue. In such cases, operators may face substantial compensation claims.

For service continuity and customer satisfaction, the only thing telecom service providers need to do is to protect their systems with the RIGHT LIGHTNING PROTECTION DESIGN. When lightning strikes a base station or a telecom tower, all facilities in its vicinity may be affected; the resulting major damage may cause serious problems for the telecom company.

Historically, lightning protection and grounding systems installed for telecommunication systems have focused on protecting the systems themselves. What must not be forgotten is that lightning also harms people through step and touch voltages. If lightning strikes a facility and step voltage precautions have not been taken, people in the surrounding area may also be electrocuted. Especially for systems installed in the very center of cities, measures must be taken to ensure that people are not harmed by lightning.

In addition to human injuries, a lightning strike on a facility may damage all devices in nearby homes, therefore this issue must be addressed with an integrated approach.

In this article, we will explain the 3 main causes leading to this situation and their basic solutions.

1. The Coupling Effect of Lightning Striking a Telecom Tower Affecting Surrounding Lines

Lightning striking a telecom tower may affect all power lines within a 2 km radius. As a result of inductive coupling, this surge may travel along bidirectional lines and be directed toward nearby homes’ power, data, and telecom lines. If this area is an organized industrial zone, it can easily reach companies’ server rooms. Lightning entering through the grounding lines of nearby facilities may burn the entire electrical system.

To control these induced currents, a Type 1+2 LV Surge Protection System must be used in the panel supplying power to the telecom site. In addition, Type 1+2 or Type 1+2+3 surge protection systems should also be used in the main incoming panels of surrounding buildings.

Due to high Up values, conventional LV surge arresters may not prevent the surge from propagating to surrounding areas in facilities exposed to strong surges. At these critical points, the Raycap Strikesorb system is the most accurate and ideal solution for telecom towers. Since it is integrated in series into the system, it ensures that the surge is completely blocked.

Additionally, appropriate surge arresters must be installed on Ethernet lines, DC lines, and communication lines.

2. Increase of Ground Potential Around the Telecom System

When lightning strikes a telecom tower or system, a significant ground potential rise occurs around the telecom tower.

Under normal conditions, this issue can be resolved with equipotential bonding in nearby facilities. However, this is impossible over an area of 2–3 km. Facilities close to the telecom tower must be brought into equipotential bonding.

In this case, in order to prevent the lightning strike from spreading rapidly and powerfully, the tower grounding system must be designed accordingly.

To prevent this, the first thing we must do is keep the grounding resistance very low. Achieving a resistance value between 2–5 Ohms will be beneficial. In the grounding system we install, it is very important that electrodes are driven symmetrically and that potential gradient concepts are considered. During the design, ring conductors should be formed around the tower and electrodes should be driven accordingly. This will contribute to rapid dissipation of the surge. The impedance value should be kept as low as possible.

To achieve low impedance, attention should be paid to the following steps.

• In addition to vertical grounding electrodes, more horizontal conductors should be installed.
• In addition to resistance-reducing chemicals, soil with low resistivity may be imported.
• Steel conductors should be used in tower and equipment foundations to support foundation grounding.

In very high-risk facilities, implementing this grounding ring system in nearby facilities will prevent potential problems.

3. Magnetic Field Effect of Lightning Striking a Telecom Tower

A lightning strike also creates a significant magnetic field effect as it descends. This can damage systems on the tower as well as affect nearby facilities.

In this case, besides equipment damage, touch voltage is also a major risk. To prevent this, it is extremely important to use insulated external lightning protection systems and insulated down conductors. Completely isolating the surge and conducting it to ground, then dissipating it through radial ground rings, and protecting equipment with the Strikesorb surge protection system is the most rational and important approach.

As a lightning protection center, we offer the most accurate solutions for protecting telecom stations; with Raycap Strikesorb Systems and Gromtor Insulated External Lightning Protection Systems, we provide the right solutions to ensure that both the tower and its surroundings are not damaged.

You can find more information about our Strikesorb and insulated down-conductor systems on the Yılkomer blog page; you can contact YILKOMER engineers for site surveys and design.

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