GE D30 Instruction Manual page 485

CHAPTER 5: SETTINGS
— Establishes a maximum voltage magnitude for V2 in 'pu'. Below this magnitude, the V2
SYNCHK1 DEAD V2 MAX VOLT
voltage input used for synchrocheck is considered "Dead" or de-energized.
— Establishes a minimum voltage magnitude for V1 in 'pu'. Above this magnitude, the V1 voltage
SYNCHK1 LIVE V1 MIN VOLT
input used for synchrocheck is considered "Live" or energized.
— This setting establishes a minimum voltage magnitude for V2 in 'pu'. Above this magnitude,
SYNCHK1 LIVE V2 MIN VOLT
the V2 voltage input used for synchrocheck is considered "Live" or energized.
Notes on the synchrocheck function
1. The selected sources for synchrocheck inputs V1 and V2 (which must not be the same source) can include both a
three-phase and an auxiliary voltage. The relay automatically selects the specific voltages to be used by the
synchrocheck element in accordance with the following table.
Number V1 or V2 (source Y)
1 Phase VTs and
Auxiliary VT
2 Phase VTs and
Auxiliary VT
3 Phase VT
4 Phase VT and Auxiliary
VT
5 Auxiliary VT
The voltages V1 and V2 are matched automatically so that the corresponding voltages from the two sources are used
to measure conditions. A phase to phase voltage is used if available in both sources; if one or both of the Sources have
only an auxiliary voltage, this voltage is used. For example, if an auxiliary voltage is programmed to VAG, the
synchrocheck element automatically selects VAG from the other source. If the comparison is required on a specific
voltage, the user can externally connect that specific voltage to auxiliary voltage terminals and then use this "Auxiliary
Voltage" to check the synchronism conditions.
If using a single CT/VT module with both phase voltages and an auxiliary voltage, ensure that only the auxiliary
voltage is programmed in one of the sources to be used for synchrocheck. An exception is that synchronism cannot
be checked between Delta connected phase VTs and a Wye connected auxiliary voltage.
2. The relay measures frequency and Volts/Hz from an input on a given source with priorities as established by the
configuration of input channels to the source. The relay uses the phase channel of a three-phase set of voltages if
programmed as part of that source. The relay uses the auxiliary voltage channel only if that channel is programmed
as part of the Source and a three-phase set is not.
D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
V2 or V1 (source Z) Auto-selected combination
Source Y
Phase VTs and Phase
Auxiliary VT
Phase VT Phase
Phase VT Phase
Auxiliary VT Phase
Auxiliary VT Auxiliary
CONTROL ELEMENTS
Auto-selected
voltage
Source Z
Phase VAB
Phase VAB
Phase VAB
Auxiliary V auxiliary
(as set for source Z)
Auxiliary V auxiliary
(as set for selected
sources)
5
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