Undervoltage Restoration - GE 750 Instruction Manual

750/760
Feeder Management Relay

Undervoltage Restoration

UNDERVOLTAGE
RESTORATION
5–106
PATH: SETPOINTS S7 CONTROL
[ ] UNDERVOLT RESTORE
FUNCTION: Disabled
UNDERVOLT RESTORE
MESSAGE
RELAYS (3-7): -----
UNDERVOLT RESTORE
MESSAGE
SOURCE: Bus
PHASES REQUIRED FOR
MESSAGE
OPERATION: All Three
UNDERVOLT RESTORE
MESSAGE
MIN VOLTS: 0.90 x VT
UNDERVOLT RESTORE
MESSAGE
DELAY:
INCOMPLETE SEQUENCE
MESSAGE
TIME:
This scheme is initiated by either the Bus or Line Undervoltage elements. After the
feeder breaker has been tripped, it will display the
the function is set to "Alarm" or "Latched Alarm") and operate any programmed
output relays. Once initiated it will monitor the bus voltage level, and send a close
command to the Close Relay when the voltage on the programmed number of
phases has risen above the programmed level for a selected time interval. The
scheme is equipped with an incomplete sequence timer, so it will not remain
initiated for an indeterminate time, but will automatically reset if the voltage does
not recover during the programmed interval. Initiation of the scheme can be
canceled by a reset command. Cancellation of a previous initiation is only effective if
the voltage is above the restoration threshold. A "Block Restoration" logic input is
available to prevent both initiation and operation. It is recommended that if
automatic undervoltage restoration is to be used, that the cold load pickup feature is
also enabled, to prevent the breaker from tripping shortly after it is automatically
closed.
The
PHASES REQUIRED FOR OPERATION
is "Bus".
SOURCE
FIGURE 5–64: Undervoltage Restoration Logic
http://www.GEmultilin.com
UNDERVOLTAGE RESTORATION
Range: Disabled,
Alarm, Control
Range: Any combination of 3 to 7
Auxiliary relays
Range: Bus, Line
Range: Any One, Any Two, All Three.
Range: 0.00 to 1.25 x VT in steps of
0.01
Range: 0 to 10000 s in steps of 1
10 s
Range: 1 to 10000 min. in steps of 1
100 min
UVolt Restore Init
setpoint is seen only if
S7 Control
Alarm, Latched
message (if
UNDERVOLT RESTORE
GE Multilin