IEC 60099-6 pdf download – Surge arresters – Part 6: Surge arresters containing both series and parallel gapped structures – Rated 52 kV and less

IEC 60099-6 pdf download – Surge arresters – Part 6: Surge arresters containing both series and parallel gapped structures – Rated 52 kV and less
1General1.1scope
This part of lEC 60099 applies to non-linear metal-oxide resistor type surge arresters withspark gaps designed to limit voltage surges on a.c. power circuits.
This standard basically applies to all metal-oxide surge arresters with gaps and housed ineither porcelain or polymeric housings.
This standard specifies requirements and tests for metal-oxide surge arresters with internalseries gaps, with rated voltages 52 kv and below.
The following arrester types and ratings are presently under consideration， but are notaddressed in this standard. They will not be addressed until more information can beascertained on the individual subjects:
series gapped arresters above 54 kV;externally gapped arresters, all ratings;shunt gapped arresters, all ratings;line discharge class 2,3,4 and 5.
1.2 Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60060-1:1989，High-voltage test techniques – Part 1: General definitions and testrequirements
IEC 60060-2:1994,High-voltage test techniques – Part 2: Measuring systems
IEC 60099-1:1991,Surge arresters – Part 1: Non-linear resistor type gapped surge arrestersfor a.c. systems
IEC 60099-3:1990,Surge arresters – Part 3: Artificial pollution testing of surge arresters
IEC 60099-4:1991,Surge arresters – Part 4: Metal-oxide surge arresters without gaps for a.c.systems
Amendment 1 (1998)Amendment 2 (2001)1
IEC 60270: 2000,High-voltage test techniques – Partial discharge measurements
2Definitions
For the purposes of this part of lEC 60099, the following definitions apply.
2.1
metal-oxide surge arrester without gaps
arrester having non-linear metal-oxide resistors connected in series andlor in parallel withoutany integrated series or parallel spark gaps
NOTE See 2.55 for metal-oxide surge arrester with series gapped structures.
2.2
non-linear metal-oxide resistor
part of the surge arrester which by its non-linear voltage versus current characteristics acts asa low resistance to overvoltages,thus limiting the voltage across the arrester terminals,andas a high resistance at normal power frequency voltage
2.3
internal grading system of an arrester
grading impedance,in particular linear/non-linear resistors and/or grading capacitorsconnected in parallel to one or to a group of non-linear metal-oxide resistors and/or seriesgap，to control the voltage distribution aiong the arrester and/or between the metal oxideresistors and gaps
2.4
grading ring of an arrester
metal part usually circular in shape,mounted to modify electrostatically the voltagedistribution along the arrester
2.5
section of an arrester
complete,suitably assembled part of an arrester necessary to represent the behaviour of acomplete arrester with respect to a particular test
NOTE A section of an arrester is not necessarily a unit of an arrester.
2.6
unit of an arrester
completely housed part of an arrester which may be connected in series and/or in parallel withother units to construct an arrester of higher voltage andlor current rating
NOTE A unit of an arrester is not necessarily a section of an arrester.
2.7
pressure relief device of an arrester
means for relieving internal pressure in an arrester and preventing violent shattering of thehousing following prolonged passage of fault current or internal flashover of the arrester
2.8
rated voltage of an arrester, u.
maximum permissible r.m.s. value of power frequency voltage between its terminals at whichit is designed to operate correctly under temporary overvoltage conditions as established inthe operating duty tests, see 7.5
NOTE 1 The rated voltage is used as a reference parameter for the specification of aperating characteristics.
NOTE2 The rated voltage as defined in this standard is the 10 s power frequency voltage used in the operatingduty test after high current.Tests used to establish the voltage rating in the IEC 60099 series,，as well as somenational standards，, invalve the application of repetitive impulses at nominal impulse current with power frequencyvoltage applied.Attention is drawn to the fact that these two methods used to establish rating do not necessarilyproduce equivalent values.(A resolution to this discrepancy is under consideration.)