4.169
Date Code 20170927 Instruction Manual SEL-751 Relay
Protection and Logic Functions
Global Settings (SET G Command)
If the contact fail-safe is enabled, the relay output is held in its energized posi-
tion when relay control power is applied. The output falls to its de-energized
position when control power is removed. Contact positions with de-energized
output relays are indicated on the relay chassis and in Figure 2.15 and
Figure 2.16.
When TRIP output fail-safe is enabled and the TRIP contact is appropriately
connected (see Figure 2.19), the breaker is automatically tripped when relay
control power fails.
MIRRORED BITS
Transmit SELOGIC
Control Equations
See Appendix J: MIRRORED BITS Communications and SEL-751 Settings
Sheets for details.
Global Settings (SET G Command)
General Settings
The phase rotation setting tells the relay your phase labeling standard. Set
PHROT equal to ABC when B-phase current lags A-phase current by 120
degrees. Set PHROT equal to ACB when B-phase current leads A-phase cur-
rent by 120 degrees.
Figure 4.100 Phase Rotation Setting
Set the FNOM setting equal to your system nominal frequency. The DATE_F
setting allows you to change the relay date presentation format to the North
American standard (Month/Day/Year), the engineering standard (Year/
Month/Day), or the European standard (Day/Month/Year).
Table 4.66 General Global Settings
Setting Prompt Setting Range Setting Name := Factory Default
PHASE ROTATION ABC, ACB PHROT := ABC
RATED FREQ. 50, 60 Hz FNOM := 60
DATE FORMAT MDY, YMD, DMY DATE_F := MDY
MET CUTOFF THRES Y, N METHRES := Y
FAULT CONDITION SEL
OGIC FAULT := 50G1P OR 50N1P OR
51P1P OR 51QP OR 50Q1P OR TRIP
B
C
A
C
PHROT = ABC
A
PHROT = ACB
B
To Next Page
Loading...
