IEC 61958 pdf download

IEC 61958 pdf download.High-voltage prefabricated switchgear and controlgear assemblies – Voltage presence indicating systems
1 General
1 .1 Scope
This International Standard is applicable to voltage presence indicating systems (VPIS) incor- porated in a.c. switchgear and controlgear covered by IEC 60298 or IEC 60466. Voltage presence indicating systems are devices used to provide information to operators about the voltage condition of the main circuit of the switchgear in which they are installed. The indication of VPIS alone is not sufficient to prove that the system is dead: if operating procedures make it mandatory, relevant voltage detectors according to IEC 61 243 shall be used. This standard is also applicable to phase comparators specifically designed for use with VPIS.
1 .2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
3 Definitions
For the purpose of this International Standard the following definitions apply. 3.1 voltage presence indicating system (VPIS) device used to indicate the presence of operating voltage NOTE 1 VPIS may also be used in conjunction with phase comparators. NOTE 2 VPIS are not designed to detect reliably the absence of voltage: for this purpose, only voltage detectors or voltage detecting systems (VDS according to IEC 61 243-5) should be used. 3.2 coupling element part of the VPIS connected to the main circuit which transmits to the indicating element a signal related to the voltage condition of this circuit. Different physical principles can be used for the coupling element, for example, capacitive, resistive, optical, etc. 3.3 indicating element part of the VPIS which gives a visual indication depending on the input signal received from the coupling element 3.4 connecting point point of the indicating element where a suitable phase comparator may be connected 3.5 phase comparator apparatus which indicates the phase relationship between the connecting points of two VPIS 3.6 nominal voltage ( U n ) suitable approximate value of voltage used to identify a system or device [IEV 601 -01 -21 , modified] NOTE 1 The nominal voltage of the VPIS is the parameter associated with its clear indication. VPIS may have one nominal voltage U n , or a nominal voltage range. Limit values of the nominal voltage range are named U nmin and U nmax . NOTE 2 In this standard, the nominal voltage of a three-phase system is the normal phase-to-phase voltage. The nominal voltage of a single-phase system is the normal voltage between lines. 3.7 voltage limiting device protective device that limits the voltage at the output terminal of the coupling element in the case of insulation failure
5.3 Indication and perceptibility
5.3.1 General The indicating element of a VPIS shall provide a clear visual indication of the voltage state. The indication shall be clearly perceptible to the user when in the recommended operating position and under practical lighting conditions. Some types of VPIS are restricted to indoor use, and others are suitable for indoor and outdoor use. 5.3.2 Frequency of repetition In the case of a repetitive visual indication, the frequency of repetition shall be at least 1 Hz. This requirement shall be met for an actual line-to-earth voltage equal to, or greater than, 45 % of the nominal voltage. For a line-to-earth voltage lower than 1 0 % of the nominal voltage, the indication corresponding to “voltage not present” shall appear with no active signal allowed for a VPIS having no built-in power source. For single-phase systems, the applicable threshold values according to 5.2 shall be used. 5.3.3 Response time The indicating element of a VPIS shall indicate the change of state of voltage within 1 s. 5.3.4 Indication until power source is exhausted VPIS with a built-in power source shall give a clear indication of voltage presence until the power source is exhausted, unless their usage is limited by an indication of non-readiness or automatic shut-off.