ThispartofIEC62271 is applicable to the voltage detecting and indicating system (VDIS) to be installed on indoor and outdoor high-voltage equipment . The VDIS as defined by this document includes a coupling system per phase (capacitive, resistive coupling or other technology) to connect to live parts (main circuit). The VDIS is applicable on systems with nominal voltage s above 1 kV and service frequencies from 16,7 Hz up to and including 60 Hz. The VDIS is used to detect and indicate the presence or absence of operating voltage . It is not intended to distinguish between voltage not present (i.e. U < 10% of nominal voltage ) and dead circuit state (i.e. U =0V). NOTE1 The use of a specific means of connection to earth of the main circuit (e.g. by an earthing switch) provides the \'dead circuit\' (U =0V) state. NOTE2 The VDIS has the same threshold values as the voltage presence indicating system (VPIS) ( IEC62271‑206 ) and the voltage detecting system (VDS) ( IEC61243‑5 ) for not indicating presence of voltage and for detecting an absence of operating voltage , respectively. The VDIS is fixed on equipment such as switchgear and controlgear according to the IEC62271series or transformers according to their own standards. The products designed and manufactured in accordance with this document contribute to the safety of the users, provided they are used by skilled or instructed persons in accordance with safe methods of work and the instructions for use.