Voltage Sensing - GE 869 Instruction Manual

CHAPTER 4: SETPOINTS
NOTE:

Voltage Sensing

Traditional VT
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CT BANK NAME
This setting allows the user to specify CT bank name which will appear in all menus and
metering screens.
PHASE CT PRIMARY
Range: 1 A to 12000 A
Default: 500 A
Enter the primary rating of the three-phase feeder CTs wired to the relay phase CT
terminals. With the phase CTs connected in wye (star), the calculated phasor sum of the
three phase currents (Ia + Ib + Ic = Neutral Current = 3I0) is used as the input for the
neutral.
GROUND CT PRIMARY
Range: 1 A to 12000 A
Default: 500 A
Enter the primary rating of the ground CT wired to the relay ground CT terminals. When
the ground input is used for measuring the residual 3I0 current, the primary current
must be the same as the one selected for the phase CTs.
The cut-off for current measurements is 0.02 x CT. This is the minimum value above which
metering functions.
The Voltage Sensing menu provides the setup for all VTs (PTs) connected to the relay
voltage terminals.
The 869 can be connected to 4 VTs, i. e. three-phase VTs from either a Wye (Star) or a Delta
connection, and one auxiliary VT. The VT inputs setup for the 869 is shown below:
Path: Setpoints > System > Voltage Sensing > Ph VT Bnk1-J2
PHASE VT BANK NAME
Range: Any combination of 13 alphanumeric characters
Default: Ph VT Bnk 1-J2
Enter the name of the phase voltage from bank J2.
PHASE VT CONNECTION
Range: Wye, Delta
Default: Wye
Select the type of phase VT connection to match the VTs (PTs) connected to the relay.
PHASE VT SECONDARY
Range: 10.0 to 240.0 V in steps of 0.1 V
Default: 120.0 V
Select the output secondary voltage for phase VTs connected to the J2 bank.
PHASE VT RATIO
Range: 1.00 to 5000.00 in steps of 0.01
Default: 1.00
Select the phase VT ratio to match the ratio of the VTs connected to the J2 bank.
AUX. VT NAME
Range: Any combination of 13 alphanumeric characters
Default: Ax VT Bnk1-J2
Enter the name of the auxiliary voltage from bank J2.
SYSTEM
4–69