GE 850 - Page 411

CHAPTER 6: PROTECTION SETPOINTS FREQUENCY ELEMENTS
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–143
Figure 6-62: Overfrequency Protection logic diagram
892738A3.cdr
LED: PICKUP
SETPOINTS
BLOCK :
Off=0
AND
SETPOINTS
OVERFREQ 1 FUNCTION : Disabled Alarm Latched Alarm Configurable
OR
Voltage Inputs
None
SETPOINTS
OVERFREQ 1 PICKUP : f ≥ PICKUP RUN
SETPOINTS
OVERFREQ 1 PICKUP DELAY : t
PKP
t
DPO
OVERFREQ 1 DROPOUT DELAY :
Overfreq1 OP
FlexLogic Operands
Overfreq1 PKP
AND AND
Command
RESET
OR
LED: ALARM
SETPOINTS
OVERFREQ 1 MINIMUM OPERATING VOLTAGE : V ≥ MINIMUM FREQUENCY f RUN
SETPOINTS
OUTPUT RELAYS (3): Do Not Operate , Operate
S
LATCH
Set-
Dominant
R
Trip
AND
LED: TRIP
Operate Output Relay 1 (TRIP)
WYE
DELTA
VA
VAB
VB VBC VC VCA
Vx
SETPOINTS
OVERFREQ 1 SIGNAL INPUT :
Positive -
sequence
Composite
X