If the line is closed where a three-phase VT failure is present, the overcurrent detector will not operate and a VTS
block will be applied. Closing onto a thr
ee-phase fault will result in operation of the overcurrent detector and
prevent a VTS block being applied.
3.4 VTS IMPLEMENTATION
VTS is implemented in the SUPERVISION column of the r
elevant settings group.
The following settings are relevant for VT Supervision:
● VTS Status: determines whether the VTS Operate output will be a blocking output or an alarm indication
only
● VTS PickupThresh: determines the threshold at which the phase voltage detectors pick up
● VTS Reset Mode: determines whether the Reset is to be manual or automatic
● VTS Time delay: determines the operating time delay
● VTS I> Inhibit: inhibits VTS operation in the case of a phase overcurrent fault
● VTS I2> Inhibit: inhibits VTS operation in the case of a negative sequence overcurrent fault
VTS is only enabled during a live line condition (as indicated by the pole dead logic) to prevent operation under
dead system conditions.
3.5 VTS LOGIC
This logic will only be enabled during a live line condition (as indicated by the pole dead logic) to prevent operation
under dead system conditions (i.
e. where no voltage will be present and the VTS I> Inhibit overcurrent element will
not be picked up).
P24xM Chapter 14 - Supervision
P24xM-TM-EN-2.1 277