![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 1025](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_12167261025.webp)
Date Code 20171006
Instruction Manual
SEL-400 Series Relays
Instruction Manual
S E C T I O N
7
Metering
The relay provides extensive capabilities for metering important power system
parameters.
This section provides basic information about metering capabilities in typical
SEL-400 series relays. Not all SEL-400 series relays support every metering fea-
ture described in this section. See
Section 7: Metering, Monitoring, and Reports
of the product-specific instruction manual for information on the specific meter-
ing capabilities of a specific relay.
SEL-400 series relays typically provide the following metering modes for measur-
ing power system operations:
➤
Instantaneous Metering on page 7.2
➤
Maximum/Minimum Metering on page 7.5
➤
➤
➤
Synchrophasor Metering on page 7.10
➤
➤
➤
Protection Math Variable Metering on page 7.12
➤
Automation Math Variable Metering on page 7.13
➤
Remote Analog Metering on page 7.13
Monitor present power system operating conditions with instantaneous metering.
Maximum/Minimum metering displays the largest and smallest system devia-
tions since the last reset. Demand metering includes either thermal or rolling ana-
lyzes of the power system and peak demand metering. Energy metering displays
the megawatt-hours imported, megawatt-hours exported, and total megawatt-
hours. Time-synchronized metering displays the line voltage and current syn-
chrophasors.
The relay processes various sets of currents and voltages, depending on the spe-
cific relay.
Use the
MET
command to access the metering functions. Issuing the
MET
com-
mand with no options returns fundamental measurement quantities. The
MET
command followed by a number,
MET
k
, specifies the number of times the com-
mand will repeat (
k
can range from 1–32767). This is useful for troubleshooting
or investigating uncharacteristic power system conditions.
lists some common
MET
command variants.
Table 7.1
MET Command (Sheet 1 of 2)
Name
Description
MET
Display fundamental line metering information
MET RMS
Display rms line metering information
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...