GE Multilin 565 Instruction Manual page 85

Location Message Line
S 9.1
SETPOINTS
VOLTAGE
Table 6-1 Phase Configuration for Voltage Alarms and Trips
VT CONNECTION
WYE
OPEN DELTA
S 9.2
VT CONNECTION
Only message S 9.21 will appear if the VT connection is selected as NONE in message S 9.2.
S 9.3
VT NOMINAL SEC
VOLTS 120 VOLTS
S 9.4
VT PRIMARY VOLTS
S 9.5
ZERO VOLTS
DETECT
Description
The setpoints page 9 header. The 565 Relay can provide protection
against voltage related faults. In this page the voltage related setpoints are
entered.
UNDERVOLTAGE
TRIP
ANY TWO
PHASE
TWO MEASURED
PHASES
(Vab & Vbc)
This message asks for the type of voltage transformer sensing which you
intend to use. There are three possible systems, as shown in wiring Figure
WYE
2.6. The choices for the setpoint are:
1. Wye.
2. Open Delta.
3. Delta/Wye
4. None
The Delta/Wye choice allows the 565/575 to measure secondary voltages
wired as Wye and display them as phase to phase quantities on the
primary side of a Delta/Wye connected transformer. Hence, selecting
Delta/Wye does not multiply the result by √3. For example:
In a 2.4 kV:120 V PT system (i.e. 120 V into the relay), WYE displays 2.4 kV
A-N, DELTA/WYE displays 2.4 kV A-B, NOT 2.4 kV × √3.
If none is selected, voltage sensing will be disabled.
Refer to your system specifications or one line diagram to determine which
your system is. Use the NEXT CHOICE key to select the appropriate one
and press the STORE Key to save the new value.
The voltage transformer which you are using to sense voltage may operate
at various secondary voltages depending on the sensing system used.
The 565/575 has the ability to be programmed for the desired secondary
rating, which should be the rated secondary voltage stamped on the
transformer's nameplate. This will be the phase to neutral voltage for a Wye
system, or a phase to phase voltage for an Open Delta system. The range
is from 48 to 240 V in steps of 0.1 V.
The primary voltage of the VT which monitors the feeder is entered here.
This is the "nameplate" primary voltage. The voltage transformer primary
1.20 kV
rating range is from 0.10 to 69 kV in steps of 0.01 kV.
When enabled, this setpoint allows undervoltage alarms and trips to occur
with the 565/575 reading all phase voltages as zero. For the 565/575, zero
ENABLED
is when the voltage is below 48% of the nominal rating. When disabled, all
phases reading below 48% are considered a normal no voltage condition.
Thus, no alarms or trips will be declared. As always, undervoltage trips
SETPOINTS MODE - VOLTAGE
UNDERVOLTAGE
OVERVOLTAGE TRIP
ALARM
ANY SINGLE
PHASE
ONE MEASURED ONE MEASURED
PHASE
(Vab OR Vbc)
OVERVOLTAGE
ANY SINGLE ANY SINGLE
PHASE
ONE MEASURED
PHASE
(Vab OR Vbc) (Vab OR Vbc)
ALARM
PHASE
PHASE
5-41