FOREWORD
1 General
   1.1 Scope
   1.2 Normative references
2 Service conditions
3 Definitions
4 Ratings
   4.1 Rated voltage
   4.2 Rated insulation level
   4.3 Rated frequency
5 Design and construction
   5.1 General
        5.1.1 Parts of VPIS
        5.1.2 Phase comparison
        5.1.3 Degree of protection (IP code)
        5.1.4 Impact resistance
        5.1.5 Testing element
   5.2 Threshold values for voltage presence indication
   5.3 Indication and perceptibility
        5.3.1 General
        5.3.2 Frequency of repetition
        5.3.3 Response time
        5.3.4 Indication until power source is exhausted
   5.4 Coupling element and voltage limiting device
        5.4.1 Insulation of coupling element
        5.4.2 Voltage limiting device
        5.4.3 Threshold voltage of voltage limiting device
        5.4.4 Earth fault conditions
        5.4.5 Maximum current delivered by the connecting point
   5.5 Marking
   5.6 Phase comparator and connecting point
        5.6.1 General
        5.6.2 Clear indication of phase comparators
        5.6.3 Perceptibility of indication
        5.6.4 Indication in case of absence of voltage on one side
        5.6.5 Indication in case of absence of voltage on both
               sides
   5.7 Electromagnetic compatibility (EMC)
6 Type tests
   6.1 General
        6.1.1 Sequence of tests
        6.1.2 Test specimens
        6.1.3 Conditioning procedure
        6.1.4 Test voltages
        6.1.5 Test conditions
        6.1.6 Values of currents and voltages
        6.1.7 Tolerances
   6.2 Arrangement, assembly, marking, and instructions for use
   6.3 Clear indication of VPIS
   6.4 Response time of VPIS
   6.5 Dielectric strength of the coupling element of VPIS
   6.6 Maximum current delivered by the connecting point
   6.7 Voltage limiting device
        6.7.1 General
        6.7.2 Threshold voltage
        6.7.3 Current-carrying capacity
   6.8 Clear perceptibility of visual indication
        6.8.1 Test voltages
        6.8.2 Test set-up
        6.8.3 Test procedure
        6.8.4 Test assessment
        6.8.5 Perceptibility of indication at maximum applied
               voltage
        6.8.6 Perceptibility of indication at low light level
   6.9 Impact resistance
   6.10 Clear indication of phase comparators
        6.10.1 Test set-up
        6.10.2 Incorrect phase relationship
        6.10.3 Correct phase relationship
        6.10.4 Absence of voltage on one side
        6.10.5 Absence of voltage on both sides
   6.11 Electromagnetic compatibility tests (EMC)
   6.12 Indication until power source is exhausted
        6.12.1 Test set-up
        6.12.2 Determination of test voltage
        6.12.3 Test procedure
        6.12.4 Repetition of test
        6.12.5 Multiple power sources
        6.12.6 Test assessment
7 Routine tests
   7.1 General
   7.2 Clear indication
8 Guide to the selection of VPIS
9 Information to be given with enquiries, tenders and orders
10 Instructions for use
   10.1 General
   10.2 Instructions for use of VPIS
   10.3 Instructions for use of phase comparators
11 Safety