In June 2006, Surge Technology was approached by Graham Smith of Energy Management, regarding the surge and lightning problems being experienced at Pezula Private Estate.
Even though the Knysna area is perceived as a low lightning area and thus low risk, Pezula Private Estate had suffered damages in excess of R250 000 to its CCTV system, access control and electrified fence system due to lightning and overvoltage damage.
Pezula had asked the company, The Corporation, which does the maintenance on the site, to obtain quotations for the required surge and lightning protection equipment, but these proved to be very expensive and Pezula approached Graham Smith of Energy Management to investigate alternative solutions.
The insurance industry recommended that Surge Technology be contacted for a quotation based on its excellent solutions offered to other clients.
It was decided that Surge Technology needed to conduct a site inspection to gain first-hand knowledge of the site and make a risk evaluation of the site. Paul van As of Surge Technology and Graham Smith of Energy Management met on site with Rossouw Engelbrecht, the technician from The Corporation, and did a thorough site inspection.
It was found that the initial proposals offered to Pezula were incorrect, and Surge Technology submitted a complete proposal, which came in at less than 20% of the original proposal. Naturally, the client was very concerned at the massive cost reduction and was concerned that the proposal would offer adequate protection.
Surge Technology assured them that this was a complete solution, and based on over 20 years of experience protecting similar systems in much harsher lightning areas, offered many sites as reference.
The solution offered by Surge Technology was more cost-effective mainly due to the fact that the solution offered was specific to the site and not a general protection approach, as had been previously tendered, and thus resulted in a major cost saving to the client. The products recommended would offer the highest level of protection in the most cost-effective manner instead of trying to protect each piece of equipment individually.
Typically, DEHNguard Class 2 arresters were installed in the electrical distribution boards rather than Class 3 Plugtop type surge arresters which, although fitted at each piece of equipment, cannot offer the required level of protection. SANS 10142-1:2003 states that Class 3 arresters can only be used if Class 2 arresters are installed upstream.
In addition, Surge Technology pointed out typical installation errors, which were easy to rectify at next to no cost, but which resulted in the surge and lightning protection being able to operate more effectively. The biggest factor being that earths must be positively bonded to ensure good conductivity, and most importantly, potential equalisation. When equipment is correctly earthed and bonded, surge currents flow via the earth paths instead of via expensive equipment causing unnecessary damage.
The site had a very high exposure to surge, lightning and overvoltage damage due to the fact that the cable runs are extremely long and all daisy-chained. This meant that in the event of a surge, it would flow along the length of the cable, affecting all equipment.
Although extensive use had been made of fibre optic cabling between buildings, the site was exposed to damage via copper cables leaving the buildings to field equipment and these cables all required surge arresters.
The Surge Technology proposal was accepted by Pezula and installed by Rossouw Engelbrecht, the technician from The Corporation. Shortly after the installation, the Knysna area had major storms hit the area with intense lightning activity. The South African Weather Services Lightning Detection Network recorded a strike of 140kA in the area and no damage was reported to any of the equipment that had been protected.
This just goes to show that even though the client perceived it would be expensive to approach the experts, the additional costs of having the initial site inspection resulted in a considerable saving, as the most cost-effective solution was proposed, which was considerably cheaper than a so-called off-the-shelf solution. In addition, due to the fact that other minor faults were identified by experts in the field and then rectified, it has prevented further damage.
Pezula now has the peace of mind that by approaching specialists in the field of surge and lightning protection, it has the correct solution which will minimise the risk of further damage, and the total solution has resulted in a major cost saving.
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