Dead Busbar And Live Line; Dead Busbar And Dead Line; Check Synchronism Settings - GE MiCOM P40 Agile Technical Manual

P44x/EN AP/Hb6
(AP) 5-144
5.9.2

Dead Busbar and Live Line

If there is a circuit breaker and busbar at the remote end of the radial feeder mentioned
above, the remote breaker might be reclosed for a dead busbar / live line condition.
5.9.3

Dead Busbar and Dead Line

This mode is not integrated in the internal logic, however it can be created using a dedicated
PSL:
This setting may also be used to allow manual close with specific test conditions on the CB.
5.9.4

Check Synchronism Settings

The main three phase VT location (busbar or line is set in the 'CT & VT RATIOS / Main VT
Location' setting to allow the previously described logic to operate correctly. (see DDB
description below)
Note that the check synchronism VT input may be driven from either a phase to phase or
phase-to-neutral voltage 'CT & VT Ratios / C/S Input' cell.
If the VTS feature internal to the relay operates, the check synchronism element is inhibited
from giving an 'Allow Reclosure' output. This avoids allowing reclosure in instances where
voltage checks are selected and a VT fuse failure has made voltage checks unreliable.
Measurements of the magnitude angle and delta frequency (slip frequency) – system rated
frequency is displayed by default in the event of problems with the delta f calculation: No line
voltage or no bus voltage or neither of the check synchronism voltages are displayed in the
'MEASUREMENTS 1' column.
Individual System Check logic features can be enabled or disabled by means of the C/S
Check Scheme function links. Setting the relevant bit to 1 will enable the logic, setting bits to
0 will disable that part of the logic. Voltage, frequency, angle and time-delay thresholds are
shared for both manual and autoreclosure, it is the live/dead line/bus logic which can differ.
Application Notes
MiCOM P40 Agile P442, P444