IEC 60871-1-2014 pdf free download.Shunt capacitors for a.c. power systems having a rated voltage above 1 000 V-Part 1: General.
IEC 60871-1 gives requirements for capacitors intended for use in the following conditions:
a) Residual voltage at energization
This shall not exceed 10% of the rated voltage (see Clause 21, Subclause 19.2 and Annex 0).
b) Altitude
If the altitude exceeds 1 000 m above sea level a correction factor shall be applied to all external insulation requirements as stipulated in Clause 18.
c) Ambient air temperature categories
Capacitors are classified in temperature categories, each category being specified by a number followed by a letter. The number represents the lowest ambient air temperature at which the capacitor may operate. The letters represent upper limits of temperature variation ranges, having maximum values specified in Table 1. The temperature categories cover the temperature range of —50 °C to +55 °C.
The lowest ambient air temperature at which the capacitor may be operated should be chosen from the five preferred values ÷5 DC. —5 °C. —25 °C, —40 °C, —50 DC.
NOTE With the agreement of the manufacturer, the capacitor can be used at a lower temperature than the limits above, provided that energization takes place at a temperature at or above these limits (see 27.3.1).
Table 1 is based on service conditions in which the capacitor does not influence the ambient air temperature (for example outdoor installations).
Any combination of minimum and maximum values can be chosen for the standard temperature category of a capacitor, for example —40/A or —5/C. Preferred standard temperature categories are: —40/A, —25/A, —5/A and —5/C.
4.2 Unusual service conditions
Unless otherwise agreed between manufacturer and purchaser, this standard does not apply to capacitors, the service conditions of which, in general, are incompatible with the requirements of the present standard.
5 Quality requirements and tests
5.1 General
Clauses 5 to 17 give the test requirements for capacitor units.
Supporting insulators, switches, instrument transformers, external fuses, etc. shall be in accordance with relevant IEC standards.
NOTE The year of issue (version number) of referred standards is given in test reports.
5.2 Test conditions
Unless otherwise specified for a particular test or measurement, the temperature of the capacitor dielectric shall be in the range +5 °C to +35 °C.
When a correction has to be applied, the reference temperature to be used is +20 °C, unless otherwise agreed between the manufacturer and the purchaser.
It may be assumed that the dielectric temperature of the capacitor unit is the same as the ambient temperature, provided that the capacitor has been left in an unenergized state at a constant ambient temperature for an adequate period.
The a.c. tests and measurements shall be carried out at a frequency of 50 Hz or 60 Hz independent of the rated frequency of the capacitor, if not otherwise specified.
6 Classification of tests
6.1 General
The tests are classified as routine tests, type tests and acceptance tests.
Any combination of minimum and maximum values can be chosen for the standard temperature category of a capacitor, for example —40/A or —5/C. Preferred standard temperature categories are: —40/A, —25/A, —5/A and —5/C.
4.2 Unusual service conditions
Unless otherwise agreed between manufacturer and purchaser, this standard does not apply to capacitors, the service conditions of which, in general, are incompatible with the requirements of the present standard.
5 Quality requirements and tests
5.1 General
Clauses 5 to 17 give the test requirements for capacitor units.
Supporting insulators, switches, instrument transformers, external fuses, etc. shall be in accordance with relevant IEC standards.
NOTE The year of issue (version number) of referred standards is given in test reports.
5.2 Test conditions
Unless otherwise specified for a particular test or measurement, the temperature of the capacitor dielectric shall be in the range +5 °C to +35 °C.
When a correction has to be applied, the reference temperature to be used is +20 °C, unless otherwise agreed between the manufacturer and the purchaser.
It may be assumed that the dielectric temperature of the capacitor unit is the same as the ambient temperature, provided that the capacitor has been left in an unenergized state at a constant ambient temperature for an adequate period.
The a.c. tests and measurements shall be carried out at a frequency of 50 Hz or 60 Hz independent of the rated frequency of the capacitor, if not otherwise specified.
6 Classification of tests
6.1 General
The tests are classified as routine tests, type tests and acceptance tests.IEC 60871-1 pdf download.