Schweitzer Engineering Laboratories SEL-311C - Maximum;Minimum Metering; Maximum;Minimum Metering Updating and Storage

8.29
Date Code 20060320 Instruction Manual SEL-311C Relay
Breaker Monitor and Metering Functions
Maximum/Minimum Metering
Maximum/Minimum Metering
View or Reset
Maximum/Minimum
Metering Information
Via Serial Port
See MET M—Maximum/Minimum Metering on page 10.23. The MET M
command displays maximum/minimum metering for the following values:
The MET RM command resets the maximum/minimum metering values.
Via Front Panel
The information and reset functions available via the previously discussed
serial port commands MET M and MET RM are also available via the front-
panel {METER} pushbutton. See Figure 11.2.
Maximum/Minimum
Metering Updating
and Storage
The SEL-311C updates maximum/minimum values, if the following
conditions are met:
➤ SELOGIC control equation setting FAULT is deasserted
(= logical 0).
The factory default setting is set with time-overcurrent and
distance element pickups:
FAULT = 51G + 51Q + M2P + Z2G
If there is a fault, these elements pick up and block updating of
maximum/minimum metering values.
➤ The metering value is above the previous maximum or below
the previous minimum for two cycles.
➤ For voltage values, the voltage is above 13 V secondary.
➤ For current values, the currents are above:
➢ 0.25 A secondary {5 A nominal}
➢ 0.05 A secondary {1 A nominal}
➤ Megawatt and megavar values are subject to the above voltage
and current thresholds.
Currents
I
A,B,C
Input currents (A primary)
I
G
Residual ground current (A primary; I
G
= 3I
0
= I
A
+ I
B
+ I
C
)
I
P
Polarizing current (A primary)
Voltages
V
A,B,C
Input voltages (kV primary)
V
S
Input voltage (kV primary)
Power
MW
3P
Three-phase megawatts
MVAR
3P
Three-phase megavars