High Voltage Surge Arresters
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995477 High Voltage Surge Arresters Buyer's Guide Power and productivity for a better world1

labie itents Product information Introduction 3 Dfinitions 4 Simplified slection proc驩dure 7 Design features - Porcelain-housed surge arresters, EXLIM 15 Design features - Silicone polymer-housed surge arresters, PEXLIM 17 The PEXLINK concept 22 Quality control and testing 28 Technical information Zinc oxide surge arresters with silicone polymer-housed insulator: PEXLIM R, IEC class 2 29 PEXLIM Q, IEC class 3 36 PEXLIM P-X, IEC class 4 45 PEXLIM P-Y, IEC class 4 52 HS PEXLIM P-T, IEC class 4 59 HS PEXLIM T-T, IEC class 5 65 Zinc oxide surge arresters with porcelain-housed insulator: EXLIM...

Safe, secure and conomie supply of electricity with ABB surge arresters ABB surge arresters are the primary protection against atmospheric and switching overvoltages. They are generally connected in parallel with the equipment to be protected to divert the surge current. The active elements (ZnO blocks) of ABB surge arresters are manufactured using a highly non-linear ceramic resistor material, composed primarily of zinc oxide mixed with other metal oxides and sintered together. Strong focus on quality at all stages, from raw material through to finished product, ensures that ABB surge...

Dfinitions NOTE! The standards referred to hereunder are the latest ditions of IEC 60099-4 and ANSI/IEEE C62.11 - ANSI (MCOV) ANSI lists the maximum continuous operating voltage (MCOV) for all arrester ratings used in a table. The value is used in all tests specified by ANSI. MCOV is less stringent as regards uneven voltage distribution in an arrester. Temporary overvoltages (TOV) Temporary overvoltages, as differentiated from surge overvolt-ages, are oscillatory power frequency overvoltages of rela-tively long duration (from a few cycles to hours). The most common form of TOV occurs on the...

- Single-impulse energy This is the maximum permissible energy, which an arrester may be subjected to in one single impulse of 4 ms dura-tion or longer and remain thermally stable against speci-fied TOV and Uc. NOTE! Corresponding values based on Uc are obtained by multiplying the catalogue values by the ratio Ur/Uc. Short-circuit capability This is the ability of an arrester, in the event of an overload due to any reason, to conduct the resulting system short-circuit current without violent shattering which may damage nearby equipment or injure personnel. After such an operation, the...

Dfinitions Transmission Line Arresters Backflashover Occurs when lightning strikes the tower structure or overhead shield wire. The lightning discharge current, flowing through the tower and tower footing impedance, produces potential differences across the line insulation. If the line insulation strength is exceeded, flashover occurs i.e. a backflashover. Backflashover is most prevalent when tower footing impedance is high. Compact insulation lines Transmission lines with reduced clearances between phases and between phase and earth and with lower insulation level withstand than for normal...

Simplified slection procdure The s驩lection is carried out in two major steps: - Matching the electrical characteristics of the arresters to the system's electrical demands - Matching the mechanical characteristics of the arresters to the system's mechanical and environmental requirements. The final selection is reflected in the arrester type designation. System/arrester parameters System parameters Arrester parameten Insulation Levels Uw/Uws Protective Levels --------------------------------------- Up/Ups TOV capability T0V --------------------------------------VOLTAGE Um Maximum system...

Flowchart for simplified slection of surge arresters Electrical slection System voltage (Um) System earthing Rated voltage (Ur0) See Table 1 Select rated voltage = maximum (Ur0, Ur1,... Urn) Earth-fault duration Other TOV (amplitude & duration) Rated voltage (Ur1,...,rn = Utov1/T1 ...Utovn/Tn) [TOV curves] Line/apparatus energy Line discharge class and arrester type See Table 2 Equipment external withstand values (Uwl, Uws) Calculate protection margins ((Uwj/Upj) - 1) x 100) ((Uws/Ups) - 1) x 100) YES Mechanical s驩lection SELECTION COMPLETE Pollution level Creepage distance Short-circuit...

Matching the system characteristics Arrester rated voltage (Ur) For each system voltage, the tables "Guaranteed protective data" show a range of Ur and maximum continuous operating voltages Uc, all of which are capable of withstanding the ac-tual continuous operating voltage (Uca) with sufficient margin. Hence, the selection of Ur is only a function of the applied temporary overvoltages, TOV, (Utov), taking into account their amplitudes and duration. TOV are long-duration, mostly power frequency (p.f.) or nearly p.f. voltages, with or without harmonics, generated by system events. The...

Matching the system characteristics Energy capability Normal discharge (2 impulses) application kJ/kV (Ur) range (Um) EXLIM R 2 5.0 < 170 kV PEXLIM R 2 5.1 < 170 kV EXLIM Q 3 7.8 170-420 kV PEXLIM Q 3 7.8 170-420 kV EXLIM P 4 10.8 362-550 kV PEXLIM P-X 4 12.0 362-550 kV PEXLIM P-Y 4 12.0 330-550 kV HS PEXLIM P 4 10.5 362-550 kV EXLIM T 5 15.4 420-800 kV HS PEXLIM T 5 15.4 420-800 kV Protection levels (Upl and Ups) For insulation coordination purposes, consider the lightning impulse protection level (Upl) at 10 kA for Um < 362 kV and at 20 kA for higher voltages. Similarly, the switching...

Matching the system characteristics Protection margins Protection margins (in %), calculated at coordinating impulse currents as per Table 3, are defined as follows: - Margin for lightning impulses = ((UW|/Upi)-1) x 100, where Uwl is the external insulation withstand of the equipment against lightning impulses. - Margin for switching impulses = ((Uws/Ups)-1) x 100 where Uws is the external insulation withstand of the equipment for switching impulses. Note! ANSI standards refer to Uwl as BIL and Uws as BSL. Margins are normally excellent due to the low Upl, Ups and also that most equipment...