Nmetal-oxide surge arrester pdf files

This is especially true for surge arresters, which are generally installed on the train roof, immediately adjacent to the pantograph, as they must protect all downstream electrical equipment against incoming overvoltages. It eliminates the risk of spark over and also the risk of shock to the system when the gaps break down. A surge arrester is capable of repeating these functions a large number of times as specified. Metaloxide surge arresters in highvoltage power systems. Hvdc valve arrester with several parallel metal oxide columns in a common housing. Application guidelines overvoltage protection metaloxide.

A surge arrester is a protective device for limiting surge voltages on equipment by diverting surge current and returning the device to its original status. The gap is generally a single air gap in series with the arrester the fundamental difference between this arrester. Tasks and operating principles of metaloxide arresters. They are very reliable devices that are able to offer decades of service without causing any. Also considered in this document are assessment methods carried out when the arrester is off line or in the lab. Metal oxide zno surge arrester type series sb 6 to 396sma0 previously sb xxx10. At the normal operating condition, the leakage current in the zno is very low as compared to other diverters. Metal oxide zno surge arrester metalloxidableiter zno. Equipment mounted on the outside of such rolling stock must be designed to withstand faster airflow.

Guidelines for selection see vde 06755 or iec 600995 design type tested according to iec 600994 active part reinforced with frp rods. The mor has roughly the same characteristics as a standard mov arrester. Selection of metal oxide zno surge arresters the selection of the rated and the continuous operating voltage of the arresters depends on the neutral point treatment of the network. The externally gapped line arrester egla has two basic components, the metal oxide resistor mor and series gap. A tool for lightning stroke analysis muhammad shaban academia. Todays technology for surge arresters intended for use in mediumvoltage systems is the gapless.