Sparks Electrical News January 2019

EARTHING & LIGHTNING

12

A SIMPLER APPROACH FOR SURGE AND LIGHTNING PROTECTION INSURANCE FOR THATCHED ROOFED BUILDINGS

per SANS Code of Practice 10313. • A certificate of compliance (COC) is required before the in- surance policy can be underwritten, as a method of assur- ance that the components will work and the workmanship is compliant. • Whenever a property is sold, the COC must be renewed. “DEHN is able to guarantee or offer insurance as a combina- tion of public and product liability, professional indemnity and the underwriting of electronic equipment insurance,” explains Oelofse. “The company is proud to introduce DEHNinsure for thatched roofs powered by HVI. The three-in-one offering of product and public liability, professional indemnity, and electronic equipment insurance means that insurance companies will have the surety and peace of mind of knowing that the damages they used to pay for, or equipment they used to replace as a result of lightning strikes, will now be covered or repaid by DEHN Africa, in the event of failure for the reasons outlined above. This is all due to the com- bination of today’s technology improvements in lightning protec- tion and DEHN Africa’s faith in its products, systems, employees and solutions,” concludes Oelofse.

sufficiently, and also needs to be serviced annually, as insufficient bonding and earthing may lead to flashovers to the thatch roof and hazardous step and touch potentials around the mast. A mast alone is not sufficient to prevent damage to the equipment in a home, so a separate surge protective device is still necessary.” Today, however, the nature of lightning protection for thatched roofs has changed with improvements in technology. “For some years now, DEHN Africa has provided lightning pro- tection system (LPS) components for use specifically on thatched roofs,” Oelofse says, “and our high-voltage-resistant insulated (HVI) lightning protection system, which is compact and neat, re- moves the need for a 30+ metre lightning mast. The HVI system is far less visible to the naked eye and arguably provides better protection from a lightning strike than a thirty-metre mast. Plus it is accepted by leading insurance companies.” Oelofse says that, given the technical expertise offered by the HVI technology, and the company’s confidence in its product, DEHN Africa is now prepared to offer insurance guarantees linked to its HVI system, through the launch of DEHNinsure. According to the terms and conditions of insurance underwrit- ers as regards thatched roofs: • All insurance companies require that an LPS be installed, as

DEHN Africa has been involved in a number of installations of lightning protection systems for thatched roofs and, in what is be- lieved to be a first in South Africa, has launched a new and excit- ing initiative, which combines the company’s expertise in lightning protection with a holistic insurance offering. Thatched roofs are an aesthetically pleasing option for game lodges and other buildings looking to cultivate a rural feel, but they require significant maintenance, including protective measures against the possibility of a fire outbreak. At the same time, be- cause they are so potentially flammable compared to other types of roofs, the insurance requirements on buildings with thatched roofs can be onerous. For numerous insurance companies, a thatched roof is regard- ed as a non-standard construction – in contrast to roofs made of tile, slate, concrete, asbestos, metal or zinc, which are deemed to be standard – and this is taken into account when determining home insurance cover and premiums. The insurer will expect you to take steps to reduce fire risk, these steps include the following: • Have your thatched roof installed and maintained by profes- sionals. • Protect it against fire, using fire-retardant materials that can help to delay the fire’s spread over the roof, and make sure that any chimneys are protected. • Have fire extinguishers strategically available, and service them annually. • Protect against lightning: The direct lightning flash density is high in large areas of South Africa, and can cause fires. DEHN Africa managing director, Hano Oelofse, notes that tradi- tionally, external lightning protective equipment for thatched roofs involved the use of a free-standing lightning mast, which must be higher than the thatched roof. “The idea,” he says, “is that the lightning flash will ‘seek’ a pathway to the ground and thereby discharge itself through the lightning mast; preventing a flammable roof from being struck by the lightning instead. However, the masts are highly visible which defeats the object of having a thatched roof that blends into the environment. The mast has to be installed at a height derived from the lightning risk assessment whereby the correct angle of protection is given according to each lightning protection level. The lightning mast must be high enough to cover the enire building. “A free-standing lightning mast must be earthed and bonded

Enquiries: www.dehn-africa.com

• DEHN’s LPS components for use specifically on thatched roofs are recommended for the following reasons: • The lightning current-carrying core of these conductors is coated with insulating material in such a way that the required separation distance to other conductive structural features or electric lines and pipes is easily maintained. There are no further measures required. • Flexibility and safety at the highest level are offered. • Appearance and design are becoming increasingly important for modern buildings. • HVI® conductors can be installed behind the façade, while HVI® conductors with grey sheathing can be painted the same colour as the building. • For the client (home-owner and architect) this means optimal adjustment to the architecture of the building and completely new design possibilities. • Installation takes place directly next to conductive structural parts or electric lines or pipes. • In addition, the LPS components for use specifically on thatched roofs are easy to mount – with modular components and the use of special tools, such as the HVI®-Strip, mounting is safe, quick and easy. • The LPS components are flexible when retrofitting, and subsequent installation on the roof is possible without adapting the lightning protection system.

PROTECT APPLIANCES AGAINST POWER SURGES

LED DRIVER SURGE PROTECTORS

W ith the growing demand for electricity on our power grid, and the unpredictable supply of power from both Eskom and your local mu- nicipality, along with load shedding it is important to have all valuable appliances protected from power surges. A power surge can occur when power is restored after an interruption in the electricity supply, load shedding, vandal- ism to substations, cable theft, general power outages and when socket outlets are overloaded as a result of plugging in too many devices to the same socket. Even though the duration of a spike is typically less than a thousandth of a second, never underestimate the extent of damage that could be caused to household appliances and electronic equipment. Generally, when speaking of a surge, most people would think of a lightning strike. A lightning induced surge can similarly cause irreparable damage to your electronics and household appliances. A dip in power or what is referred to as a ‘brown-out’ can also cause damage to equipment in your home. This oc-

small surges and dips in power – some that we may not even notice – the electronic parts in your equipment are degraded and parts may suffer damage. As we live in a country with unstable power supply, care to protect our household appliances and electronic equip- ment is paramount. Ellies has a range of surge protectors to cater for all needs at the home or at the office. The range includes medium surge protection adaptors, multiplugs and extension leads, plugs to protect fridges and TVs, and a high surge range with a R30 000, two-year surge war- ranty for protection of items including the telephone, fax machine or modem. Always buy good quality electrical products to use with appliances and electronic equipment, and check them reg- ularly to make sure they are in good working order. Ensure that all the electrical wiring from the distribution board to the sockets is compliant and only allow qualified electri- cians to work on the electrical wiring in a home or office.

MIMIC COMPONENTS has on offer LED driver surge protectors for series and parallel connections. The range includes thermal disconnect with built in indicators to monitor the protection status. The surge protector has a status indicator or 5 A relay contact for remote monitoring, tripping and the like. As most LED drivers do not have surge suppression between earth ground and any of the input wires – and because of the effect these have during hi-pot testing – it has been established that it is more practical to install the devices in the fixture or external to the LED driver. The maximum surge rating required is 10 kA for the high exposure level. Mimic’s surge protectors are fitted with four 10 kA varistors and connected to improve the differential mode surge capability. In addition, the LED driver surge protectors are fitted with EMI filters, containing X and Y capacitors and specially wound inductors to eliminate the flickering effect sometimes found when using LED light dimmers as well as when using emergency generators during blackout periods. They provide additional surge protection for long term reliability to minimise failure of LED lighting systems. LED driver surge protectors also suppress noise that causes interference to electronic equipment and entertainment systems.

Enquiries: +27 (0)11 490 3800

curs when the power supply drops usually by a fault in the distribution network, or when your electric- ity supplier reduces the supply. A dip in power can also be caused by appliances that draw a large amount of power when in use – you may see a slight dimming of your lights when this occurs. Surges and dips in power are beyond our control. Even though your equipment may not suffer a catastrophic failure during a surge or brown-out, over time with the

Enquiries: +27 (0)11 689 5700

SPARKS ELECTRICAL NEWS

JANUARY 2019