IEC 60433 pdf free download
IEC 60433 pdf free download.Insulators for overhead lines with a nominal voltage above 1 000 V – Ceramic insulators for AC systems – Characteristics of insulator units of the long rod type.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
long rod insulator
suspension or tension insulator consisting of an approximately cylindrical insulating part provided with sheds and equipped at the ends with external metal fittings
Note 1 to entry: The insulator is designed in such a manner that the shortest puncture path through solid insulating material is at least equal to half the arcing distance. Therefore it is a class A insulator according to
IEC 60383-1.
4 Characteristics, dimensions and type of long rod insulators
String insulator units of the long rod type are characterised by the following specified characteristics:
— the standard lightning impulse withstand voltage (see IEC 60071-1);
— the wet power frequency withstand voltage (see IEC 60071-1);
— the tensile mechanical failing load;
— the maximum nominal length L of the insulator;
— the maximum nominal diameter D of the insulating part;
— the minimum nominal creepage distance;
— the standard coupling.
The corresponding values are specified in Table 1. The minimum nominal creepage distances are based on a unified specific creepage distance of 27,8 mm/kV for the lowest value of the highest voltage for equipment corresponding to the specified value of the standard lightning impulse withstand (in accordance with IEC 60071-1).
NOTE 1 The tolerances given in IEC 60383-1 are applicable to all the dimensions in Table 1, even if the adjectives “minimum” or “maximum” are used before the term “nominal”.
NOTE 2 Dry lightning impulse withstand voltage and wet power frequency withstand voltage are specified in Table 1 for single unit string insulators. Values of withstand voltages of insulator strings consisting of more than one unit are not contained in this document.
NOTE 3 The rod diameter is not specified since it depends on the mechanical characteristics of the insulating material. Information on the definition and classification of ceramic insulating materials can be found in IEC 60672-1 and IEC 60672-3.
NOTE 4 Examples of shed profile are given in Clause 8, Choice of profile” of IEC TS 60815-2:2008.
5 Designation and marking
Long rod insulators are designated in Table 1 by the letter L, followed by a figure indicating the specified mechanical failing load in kilonewtons. Then follows the letter B or C indicating socket or clevis coupling respectively, followed by the value of the lightning impulse withstand voltage in kilovolts.
EXAMPLE:
L 160 B 550 indicates:
L: long rod insulator;
160: specified mechanical failing load, tension, 160 kN;
B: socket coupling;
550: dry lightning impulse withstand voltage 550 kV.
The insulators shall be marked either on the upper shed or on the metal parts with the name or trade mark of the manufacturer and the year of manufacture. In addition, each unit shall be marked with the specified mechanical failing load, by using the first part of the designation; for instance, the insulator shall be marked L 160 for the units with 160 kN specified mechanical failing load.
These markings shall be legible and indelible.
Figure 1 shows a long rod insulator with clevis couplings. Figure 2 shows a long rod insulator with socket couplings.IEC 60433 pdf download.
