AREVA INSTALLATION AND MAINTENANCE MANUAL

INTRODUCTION : AREVA Surge Arresters, based on state of the art technology for manufacture of Gapless Zinc Oxide Arresters, are primarily intended for over-voltage / surge protection of High Voltage Power Equipment. These Arresters could be used either indoor or outdoor and can be used up to an altitude of 3000 meters. DESCRIPTION : Each Arrester pole consists of one unit. A nameplate located on the top end casting gives complete arrester voltage rating and other relevant details. The complete arrester will include a line terminal bracket, a ground terminal bracket and terminal connectors. Fasteners are also provided to mount arrester on to the structure and also to attach the line terminal connectors to line terminal bracket. The Arrester voltage indicates maximum rms voltage at which the arrester can be stressed for a maximum period of 10 seconds. COV is the continuous operating voltage at which the arrester can be stressed continuously. If the rated voltage is exceeded above this period or COV is exceeded continuously, the arrester would be damaged. For contingencies, special rating and/or COV have to be applied and so it is advised to contact our technical department for necessary information. Recommended minimum clearances from the arrester to the earthed objects and from the arrester pole to another arrester pole have been provided in the table. PACKING AND TRANSPORTATION : All arresters are normally packed in wooden crates designed to withstand normal handling shocks. It is essential that the cases are kept in upright position always. It is essential to handle the crates carefully. RECEIVING : On receipt of the crates, detailed inspection is to be carried out for any visible signs of damage. Unpack the units carefully and examine for breakage or other damage especially to Porcelain. If damage or shortage is noticed, inform AREVA Marketing Department as well as the concerned carriers. STORAGE : It is essential that the crated arresters are stored indoor to prevent the wood getting damaged by rain or sun or moths. The floor area should preferably be concrete. Surge Monitors, if procured, also should be stored indoor and the area should be free from water logging. INSTALLATION : Before proceeding with the installation, the arresters should be identified clearly. Remove the arrester from the wooden crates. Clean the end surfaces and porcelain of the arrester thoroughly and ensure that the arrester surface is clean. The arrester should not be climbed on for any reason. Also, the arrester should not be tilted. They should be handled only in an upright position. Nylon rope can be wound around the porcelain and can be used for lifting.

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MOUNTING ARRANGEMENT

STRUCTURE

ARRESTER END CASTING

STRUCTUREBASE

GROUND TERMINALBRACKET

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Mount the arrester on to the structure. Fix the arrester to the structure with the fasteners supplied, as shown in the diagram. Connect the line end to the terminal connector and earth flat to the ground terminal bracket. It is strongly recommended to use flexible conductor for connecting line end to the terminal connector. To give the highest degree of protection, the arresters should be located near the equipment to be protected using leads of the shortest possible lengths. The arrester ground lead / earth flat should be connected to common earth. TESTING AND COMMISSIONING : No simple field tests will verify the complete characteristics of an Arrester. This requires extensive, rather specialized test facilities. Since the arrester have no series or parallel gaps, the leakage current at system line to ground voltage is a good indicator of the condition of the arrester. If the arrester is installed with the accessories, insulating base and surge monitor, the Arrester along with the insulating base (fixed to the arrester) is to be mounted on to the structure and connection to be taken through the surge monitor as shown in the drawing. The surge monitor will indicate the leakage current. It is to be noted that contamination on the porcelain surface may result in misleading readings. Under such conditions, reading should be taken after cleaning the Arrester porcelain.

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:: 3 :: If, even after this process the reading remains in red region, the arrester is to be removed from service. It is necessary to monitor the condition of arrester through surge monitor rather than relying on a Meggar test, which measures the insulation resistance of the arrester at a very low voltage. Since the arrester consist of non-linear ZnO resistor elements, the Meggar test will yield misleading results. If Electrical Tests are proposed at site, care must be taken to use a low KVA test source to prevent damage to a good arrester. For power frequency test, the voltage stress on the arrester should not ever exceed its MCOV or rated voltage for a short period. MAINTENANCE : Arrester requires no regular maintenance other than occasional inspection. In locations where porcelain becomes dirty due to contaminants, it is recommended that Arresters be cleaned periodically. A regular log of surge monitor readings (where installed) should be maintained giving leakage current and counter operation. If more operations of a particular arrester are observed through counter, analysis of the system must be undertaken to find causes for such occurrence. It recommended that arrester which has registered more operations should be removed from service for detailed testing. AREVA T&D Lightning Arresters Private Limited, AREVA T&D Lightning Arresters Private Limited R.S. 38/2, Sedarapet Main Road, Registered Office : 457, Anna Salai Sedarapet Village, PONDICHERRY 605 111 Teynampet, CHENNAI 600 018 Ph: 0413 2677401/402/403 Fax : 0413 2677 316