Golf courses usually extend over large areas and include facilities such as clubhouses, caddy sheds, change rooms, halfway houses, shelters, golf cart parking lots and widespread irrigation and sprinkler systems that ensure the quality of the greens. They are also often located in areas where low voltage power supply is not readily available and receive power from the distribution network operator as medium voltage. Lightning strikes cause about 150 deaths per year in South Africa and six percent of these occur while golfing in an open field. It is therefore advisable by DEHN Africa for these facilities to have effective lightning protection measures in place.

The first step to achieving this is an assessment of the potential risk resulting from a lighting strike as per the IEC 62305-2 (EN 62305-2) lightning protection standard and, based on these risk analysis findings, to plan protection measures. These should include a combination of external lightning protection and lightning equipotential bonding for all service lines entering and leaving a building or property, such as metal gas, water pipes and power supply feeder and control lines. 

The following points encompass the various protection measures required for the different facilities of a golf course.

Protection for shelters
The purpose of shelters on golf courses is not only to protect golfers from storms and rain, but also from lightning interference. An external lightning protection system in combination with feasible measures to reduce inadmissibly high step and touch potentials at the entrance and in the shelter are required in case of a lightning strike. Therefore, shelters should not be installed at exposed locations such as on hills, and at the edge of a forest beneath isolated trees.

Protection for clubhouses
The power supply feeder cable to the main low-voltage distribution board is often located in the basement of the clubhouse, together with different sub-distribution boards supplying power to the restaurants, halfway house, offices, shops, and other detached buildings. Regardless of whether an external lightning protection system exists, a type 1 combined arrester should be installed in the main low-voltage distribution board to prevent potentially damaging lightning currents entering through the power supply feeder cable. In addition, the sub-distribution boards should be equipped with type 2 surge arresters. Telephone and data / internet access (Uk0 lines) usually have a dedicated service room in a clubhouse, this is where a type 1 combined arrester for IT equipment is installed for the Uk0 lines near the entrance point into the building.

Office communication and RFID systems for ball machines, access control and the rental of golf carts play an important function. Thus, the network card should be protected by a surge arrester for LAN connections and the power supply by a type 3 surge arrester. However, it is equally as important to protect the protective circuit for the transmit / receiver antenna of the RFID system or for the TV and radio satellite antenna as well, near the entrance point into the building.

Caddy/ trolley shed with integrated driving range
Measures to avoid inadmissibly high step and touch voltages in case of lightning interference are imperative, particularly in the case of highly frequented entrances and shelter areas. To this end, numerous measures can be employed, for example keeping a surface resistance ≥ 100 kΩ within a limited protective area of three metres around the down conductor (e.g. five cm asphalt). As described above, lightning equipotential bonding has to be implemented for the different systems directly at the entrance point into the building and, if necessary (depending on the results of the risk analysis), further surge protection measures upstream of the terminal device should be provided.

Moreover, the same protection measures as for the clubhouse or the caddy / trolley shed must be taken for the golf cart parking garage and the cart shed.

Protecting the irrigation system
Water is mostly pumped from reservoirs, with pumps that are installed in underground ducts, but controlled and monitored from a service station. The pressurised water pipe runs throughout the entire golf course and the sprinkler systems that are supplied by these pipes maintain the grass and plants. The water flow is controlled through magnetic valves that are installed either directly at the sprinkler or in ground level boxes. In addition, the magnetic valves that activate the sprinklers are controlled by decoders, while the data transmission and power supply for the valves is provided by a two-wire ring conductor. The conductor and the magnetic valves provide the highest risk in terms of surges and, therefore corresponding surge protective devices are installed on the two-wire ring conductor at intervals not exceeding 150 m.

Protection for the service station
Lightning equipotential bonding has to be implemented at the entry point into the service station for the pressurised water pipes, the two-wire ring conductor, the IT and the power supply feeder cable and the pump line. Also, it depends on the building size as to whether further surge protection measures are necessary for the internal conductors upstream of the corresponding control systems as lightning and surge protection have to be individually adjusted to the natural and structural conditions.

The market leader DEHN, a globally active family-owned electrotechnical company with more than 1600 employees worldwide, offers innovative products and solutions as well as comprehensive services in the field of surge protection, lightning protection and safety equipment. DEHN focuses on the protection of system and building technology, the transportation, telecommunication and process sector, photovoltaic systems, wind turbines, etc. The company's continuous growth is based on more than 100 years of tradition and experience as well as highest quality standards and consistent customer and market orientation throughout the world.