4.84
SEL-787 Relay Instruction Manual Date Code 20150130
Protection and Logic Functions
Global Settings (SET G Command)
IRIGC
IRIGC defines whether IEEE C37.118 control bit extensions are in use.
Control bit extensions contain information such as Leap Second, UTC time,
Daylight-Saving Time, and Time Quality. When your satellite-synchronized
clock provides these extensions, your relay will be able adjust the
synchrophasor time-stamp accordingly.
➤ IRIGC := NONE will ignore bit extensions
➤ IRIGC := C37.118 will extract bit extensions and correct
synchrophasor time accordingly
Coordinated Universal Time (UTC) Offset Setting
The SEL-787 has a Global setting UTC_OFF, settable from –24.00 to 24.00
hours, in 0.25 hour increments.
The relay uses the UTC_OFF setting to calculate local (relay) time from the
UTC source when configured for Simple Network Time Protocol (SNTP)
updating via Ethernet. When a time source other than SNTP is updating the
relay time, the UTC_OFF setting is not considered because the other time
sources are defined as local time.
Automatic Daylight-Saving Time Settings
The SEL-787 can automatically switch to and from daylight-saving time, as
specified by the eight Global settings DST_BEGM through DST_ENDH. The
first four settings control the month, week, day, and time that daylight-saving
time will begin, while the last four settings control the month, week, day, and
time that daylight-saving time will end.
Once configured, the SEL-787 will change to and from daylight-saving time every
year at the specified time. Device Word bit DST asserts when daylight-saving time is
active.
The SEL-787 interprets the week number settings DST_BEGW and
DST_ENDW (1–3, L = Last) as follows:
➤ The first seven days of the month are considered to be in
week 1.
➤ The second seven days of the month are considered to be in
week 2.
Week Of The Month To Begin
DST
1–3, L DST_BEGW := 2
Day Of The Week To Begin DST SUN, MON, TUE, WED,
THU, FRI, SAT, SUN
DST_BEGD :=
SUN
Local Hour To Begin DST 0–23 DST_BEGH := 2
Month To End DST 1–12 DST_ENDM := 11
Week Of The Month To End DST 1–3, L DST_ENDW := 1
Day Of The Week To End DST SUN, MON, TUE, WED,
THU, FRI, SAT, SUN
DST_ENDD :=
SUN
Local Hour To End DST 0–23 DST_ENDH := 2
Table 4.37 Time and Date Management Settings (Sheet 2 of 2)
Setting Description Setting Range
Setting Name :=
Fac tory Default
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