5.7
Date Code 20081022 Instruction Manual SEL-787 Relay
Metering and Monitoring
Metering
All maximum and minimum metering values will have the date and time that
they occurred. The analog quantities from Table 5.5 are checked
approximately every 1.0 seconds and, if a new maximum or minimum value
occurs, this value is saved along with the date and time that the maximum or
minimum value occurred. Maximum and minimum values are only checked if
relay element FAULT is deasserted (no fault condition exists) for at least one
second. Additionally, the following minimum thresholds must also be met:
➤ Current magnitudes of IAWn, IBWn, and ICWn: 3% of the
nominal current (INOM • CTRn). (n=1 or 2 depending on the
winding)
➤ Current magnitude of IGWn: IAWn, IBWn, and ICWn all must
be above their thresholds (n =1 or 2 depending on the winding)
➤ Current magnitude of IN: 3% of the nominal IN rating
(INOM • CTRN)
➤ Voltage values (phase-neutral and phase-to-phase): 7.5 • PTR V
and 13 • PTR V, respectively.
➤ Power values (real, reactive, and apparent): All three currents
(IAWn, IBWn, ICWn) and all three voltages (VA, VB, VC or
VAB, VBC, VCA) must be above their thresholds.
Figure 5.7 shows an example device response to the METER M command.
=>>MET M <Enter>
SEL-787 Date: 11/01/2007 Time: 14:32:32
TRNSFRMR RELAY Time Source: Internal
MAX DATE TIME MIN DATE TIME
IAW1 (A) 607.5 11/01/2007 10:57:48 485.9 11/01/2007 10:56:20
IBW1 (A) 608.3 11/01/2007 11:02:09 604.8 11/01/2007 10:56:35
ICW1 (A) 733.7 11/01/2007 10:56:13 609.7 11/01/2007 11:02:44
IGW1 (A) 1411.5 11/01/2007 10:57:57 2.1 11/01/2007 11:02:57
IN (A) 3002.3 11/01/2007 11:03:07 177.7 11/01/2007 10:55:58
IAW2 (A) 607.8 11/01/2007 10:57:48 116.2 11/01/2007 10:56:20
IBW2 (A) 606.8 11/01/2007 11:02:09 235.8 11/01/2007 10:56:35
ICW2 (A) 608.4 11/01/2007 10:56:13 364.5 11/01/2007 11:02:44
IGW2 (A) 1200.5 11/01/2007 10:58:04 158.8 11/01/2007 11:03:33
VA (V) 10004 11/01/2007 10:57:41 6701.4 11/01/2007 11:03:30
VB (V) 10006 11/01/2007 10:58:02 6704.9 11/01/2007 11:02:32
VC (V) 10025 11/01/2007 10:56:55 6714.7 11/01/2007 11:00:30
KW3P (kW) 9626.1 11/01/2007 11:02:03 -1561.9 11/01/2007 10:56:21
KVAR3P (kVAR) 1814.3 11/01/2007 10:57:42 -7408.9 11/01/2007 11:01:17
KVA3P (kVA) 12133 11/01/2007 11:02:57 2330.7 11/01/2007 10:56:07
FREQ (Hz) 60.0 11/01/2007 11:01:18 60.0 11/01/2007 10:58:05
LAST RESET = LAST RESET = 11/01/2007 10:55:52
=>>
Figure 5.7 METER M Command Report
To reset maximum/minimum meter values, issue the MET RM command as
shown in Figure 5.8. The max/min meter values can be reset from the serial
port, the front panel, or assertion of the RSTMXMN relay element. The date
and time of the reset are preserved and shown in the max/min meter report.
=>>MET RM <Enter>
Reset Metering Quantities (Y,N)? Y <Enter>
Reset Complete
=>>
Figure 5.8 METER RM Command Response
All maximum and minimum metering values are stored to nonvolatile
memory four times per day and within one minute of the maximum and
minimum metering values being reset.
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