IEC 61958:2000 pdf download
IEC 61958:2000 pdf download.High-voltage prefabricated switchgear and controlgear assemblies – Voltage presence indicating systems.
4 Ratings
The followrng ratings of the switchgear shall also be applicable to the VPIS Incorporated In It:
— rated voltage;
— rated insulation level;
— rated frequency(ies).
In addition, the nominal voltage, or nominal voltage range, of the systems on which the VPIS can be used, shall be defined.
4.1 Rated voltage Refer to 4.1 of IEC 60694.
4.2 Rated Insulation level Refer to 4.2 of IEC 60694.
4.3 Rated frequency Refer to 4.3 of IEC 60694.
5 Design and construction
5.1 General
5.1.1 Parts of VPIS
A VPIS includes
— a coupling element;
— an indicating element;
— a connecting point (optional).
Both the coupling and Indicating elements are fixed and Incorporated In switchgear (see figure 1).
5.1.2 Phase comparison
VPIS should allow checking of phase relationship by means of a suitable phase comparator. The characteristics of the phase comparator shall be defined by the manufacturer of the VPIS.
5.1.3 Degree of protection (IP code)
Parts of the VPS which contribute to the switchgear enclosure shall meet the degree of protection defined for the switchgear.
If the VPIS includes hazardous parts when in service, it shall provide at least an IPXXB degree of protection according to IEC 60529. even when replaceable parts are removed.
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 10 $ 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 I 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.
5.4 Coupling element and voltage limiting device
5.4.1 insulation of coupling element
The coupling element shall provide adequate insulation between its output terminal and the main Circuit.
5.4.2 Voltage limiting device
To provide protection for operators against the presence of operating voltage on the connecting point. ii shall be ensured that any insulation failure of the coupling element will necessarily cause a permanent earth fault.
This shall be achieved by connecting the coupling element output terminal to earth via a voltage limiting device.
The voltage limiting device can be a specific component (for example, spark gap) or be one of the components permanently connected to the coupling element (for example, an indicating element component).
The effects caused by the response of the voltage limiting device shall be taken into account when determining the protection concept of the installation.
5.4.3 Threshold voltage of voltage limiting device
The threshold voltage of the voltage limiting device shall comply with the following requirements:
— it shall be lower than 30 % of the nominal voltage of the power system;
— it shall be less than the lowest limiting value of the dielectric strength In the remaining components of the VPIS.
5.4.4 Earth fault conditions
For systems with Insulated or resonant earthed neutral, earth fault currents are limited to low values and the equipment can be maintained In operation for a long period of time under these conditions.
In such cases, additional precautions shall be taken to ensure that either the earth fault condition can easily be observed by operators, or no dangerous voltage can occur on the connecting point for the earth fault duration.
