Frequency - GE Multilin 745 Instruction Manual

745
Transformer Management Relay
! W1 NEG SEQ
INST OC

Frequency

! FREQUENCY
5–66
c) Negative Sequence Instantaneous Overcurrent
PATH: SETPOINTS !" S4 ELEMENTS
[!] W1 NEG SEQ INST OC
FUNCTION: Disabled
W1 NEG SEQ INST OC
MESSAGE
TARGET: Latched
W1 NEG SEQ INST OC
MESSAGE
PICKUP: 10.00 x CT
W1 NEG SEQ INST OC
MESSAGE
DELAY:
W1 NEG SEQ INST OC
MESSAGE
BLOCK: Disabled
• W1(3) NEG SEQ INST OC PICKUP: Enter the level of negative sequence
current (in units of relay nominal current) above which the Winding 1(3)
Negative Sequence Instantaneous Overcurrent element will pickup and start the
delay timer.
• W1(3) NEG SEQ INST OC DELAY: Enter the time that the negative sequence
current must remain above the pickup level before the element operates.
FIGURE 5–28: Negative Sequence Instantaneous Overcurrent Logic
a) Main Menu
PATH: SETPOINTS S4 ELEMENTS
!"
[!] ! UNDERFREQUENCY
! UNDERFREQUENCY
MESSAGE
! FREQUENCY
MESSAGE
! OVERFREQUENCY
MESSAGE
The 745 can be used as the primary detecting relay in automatic load shedding
schemes based on underfrequency. This need arises if, during a system disturbance,
an area becomes electrically isolated from the main system and suffers generation
deficiency due to loss of either transmission or generation facilities. If reserve
generation is not available in the area, conditions of low system frequency occur
http://www.GEindustrial.com/multilin
!" NEG SEQ OC !" W1(3) NEG SEQ INST OC
Range: Enabled, Disabled
Range: Self-Reset, Latched, None
Range: 0.05 to 20.00 x CT in steps of
Range: 0 to 60000 ms in steps of 1
0 ms
Range: Logc Inpt 1 to 16, Virt Inpt 1 to
FREQUENCY
!"
[!]
See page 5–67.
1
[!]
See page 5–67.
2
[!]
See page 5–68.
DECAY
[!]
See page 5–70.
S4 Elements
0.01
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
GE Multilin