10-20
Serial Port Communications and Commands
Date Code 20001006
SEL-351 Instruction Manual
If no IRIG-B code is present at the serial port input or if the code cannot be read successfully, the
relay responds:
IRIG-B DATA ERROR
=>
If an IRIG-B signal is present, the relay synchronizes its internal clock with IRIG-B. It is not
necessary to issue the IRI command to synchronize the relay clock with IRIG-B. Use the IRI
command to determine if the relay is properly reading the IRIG-B signal.
LDP Command (Load Profile Report - Available in Firmware Versions 1, 2, 3 and 4)
Use the LDP command to view the Load Profile report. For more information on Load Profile
reports, see
Section 8: Breaker Monitor, Metering, and Load Profile Functions
.
MET Command (Metering Data)
The MET commands provide access to the relay metering data. Metered quantities include phase
voltages and currents, sequence component voltages and currents, power, frequency, substation
battery voltage, energy, demand, and maximum/minimum logging of selected quantities. To make
the extensive amount of meter information manageable, the relay divides the displayed information
into four groups: Instantaneous, Demand, Energy, and Maximum/Minimum.
Note:
If the serial port AUTO setting is DTA, the SEL-351 Relay response for MET and
MET D will be formatted differently on that serial port than shown below.
MET k – Instantaneous Metering
The MET k command displays instantaneous magnitudes (and angles if applicable) of the
following quantities:
Currents
I
A,B,C,N
Input currents (A primary)
I
G
Residual ground current (A primary; I
G
=3I
0
= I
A
+ I
B
+ I
C
)
Voltages
V
A,B,C,S
Wye-connected voltage inputs (kV primary)
V
AB, BC, CA,S
Delta-connected voltage inputs (kV primary)
Power
MW
A,B,C
Single-phase megawatts (wye-connected voltage inputs only)
MW
3P
Three-phase megawatts
MVAR
A,B,C
Single- and three-phase megavars (wye-connected voltage inputs
only)
MVAR
3P
Three-phase megavars
Power Factor PF
A,B,C
Single-phase power factor; leading or lagging (wye-connected
voltage inputs only)
PF
3P
Three-phase power factor; leading or lagging
Sequence
I
1
, 3I
2
, 3I
0
Positive-, negative-, and zero-sequence currents (A primary)
V
1
, V
2
Positive- and negative-sequence voltages (kV primary)
3V
0
Zero-sequence voltage (kV primary, wye-connected voltage
inputs only)
Summary of Contents for SEL-351
Page 14: ...Courtesy of NationalSwitchgear com ...
Page 16: ...Courtesy of NationalSwitchgear com ...
Page 40: ...Courtesy of NationalSwitchgear com ...
Page 74: ...Courtesy of NationalSwitchgear com ...
Page 146: ...Courtesy of NationalSwitchgear com ...
Page 186: ...Courtesy of NationalSwitchgear com ...
Page 220: ...Courtesy of NationalSwitchgear com ...
Page 304: ...Courtesy of NationalSwitchgear com ...
Page 340: ...Courtesy of NationalSwitchgear com ...
Page 380: ...Courtesy of NationalSwitchgear com ...
Page 450: ...Courtesy of NationalSwitchgear com ...
Page 506: ...Courtesy of NationalSwitchgear com ...
Page 528: ...Courtesy of NationalSwitchgear com ...
Page 534: ...Courtesy of NationalSwitchgear com ...
Page 536: ...Courtesy of NationalSwitchgear com ...
Page 550: ...Courtesy of NationalSwitchgear com ...
Page 562: ...Courtesy of NationalSwitchgear com ...
Page 570: ...Courtesy of NationalSwitchgear com ...
Page 584: ...Courtesy of NationalSwitchgear com ...
Page 602: ...Courtesy of NationalSwitchgear com ...