Overcurrent Time Phase; Overcurrent Time Neutral Or Ground; Directional Time Overcurrent Phase 67 - Siemens ISGS Operator's Manual

3.7.7 Overcurrent Time Phase 51 (Address
1700)
Use this address block to change the time phase overcur-
rent curve, pickup, time dial, and filter. Refer to Appendix A
for detailed trip curve information. The available relay subad-
dresses are listed in Table 3.11.
Subaddress Parameter Selection
1702 Curve Inverse,
Short nverse,
Long nverse,
Moderately Inverse,
Custom,
Very Inverse,
Extremely Inverse,
Definite Inverse,
Sli!Jltly Inverse,
12T w/o Unit
1703
Pickup 5 ACT's: 0.5- 20 A
or
1ACTs:0.1
4A
1705
Time Dial 0.1 -9.9
1706
Filter rms or Fundamental
1710 FreezeWfm1
01
Pickup, on Trip,
or None
1711
FreezeWfm2 on Pickup, on Trip,
or None
Table
3.11
51 Phase Configuration, Major Block 1700
The phase time overcurrent protection begins timing when
any individual phase current exceeds the pickup current set-
ting (1705). The phase time overcurrent protection cannot
te
disabled. The time overcurrent characteristic curve
(1702) may be selected from one of the curves prepro-
grammed in the relay, or a custom curve may be pro-
grammed. For the preprogrammed curves, the time dial
(1705) may be adjusted from 0.1 to 9.9, in steps of 0.1. The
function may be configured (1706) to respond on the basis
of rms sensing (fundamental plus harmonics), or on the
basis of the fundamental current value only (ignores har-
monics).
Each of the two waveform capture buffers can be indepen-
dently programmed to freeze the snapshot on pickup, on
trip, or not at all (1710 and 1711). For this protection ele-
ment, the default for buffer 1 is "on Trip" and for buffer 2 it is
"None." These settings are not included in the altemate
parameter sets.
The settings for phase time overcurrent (51) are independent
of the settings for ground time overcurrent (51N) and the
instantaneous overcurrent settings (50 and 50N).
3.7 .8 Overcurrent Time Neutral or Ground 51 N
(Address 1800)
Use this address block to change the time neutraVground
overcurrent curve, pickup, time dial, and filter. Refer to
Siemens Energy & Automation, Inc.
3
Operation
Appendix A for detailed trip curve information. The available
relay subaddresses are listed in Table 3.12.
Subaddress Parameter Selection
1801 Function Enable or Disable
1802
Curve Inverse,
Sh:Jrt Inverse,
Long nverse,
Moderately nverse,
Custom,
Very Inverse,
Extremely Inverse,
Definite Inverse,
Slightly nverse,
12T w/o U·nit
1800
Pickup 5 A CT 's: 0.5 - 2J A
or
1 A CT 's: 0. 1 - 4 A
1805
Tine Dial 0.1 - 9.9
1806
Filter rms or Fundamental
1810
Freeze Wfm1 on Piclq_Jp, on Trip,
or None
1811
Freeze Wfm2 on Pickup, on Trip,
or None
Table3.12
51N Neutral or Ground Configuration, Major
Block 1800
This function is similar to the phase time overcurrent ele-
ment described
n
section 3 .7.7, except that the protection
respond~ to current input to the fourth (intemaO CT, and this
protection can be enabled or disabled. The form of protec-
tion provided depends on the manner in which the extemal
CT's are connected to the ISGS relay. Figure 3.4 shows the
correct CT connections and polarities.
Each of the two waveform capture buffers can be indepen-
dently programmed to freeze the snapshot on pickup, on
trip, or not at all (1810 and 1811). For this protection ele-
ment, the default for buffer 1 is "on Trip" and for buffer 2
it
is
"None." These settings are not included in the altemate
parameter sets.
The settings for neutral/ground time overcurrent (51N) are
independent of the settings for phase time overcurrent (51)
and the instantaneous overcurrent settings (50 and 50N).
3.7.9 Directional Time Overcurrent Phase 67
(Address 1900)
Use this address block to change the directional time phase
overcurrent curve, pickup, time dial, and filter. In addition,
the directional sensitivity relative to normal power flow (for-
ward or reverse), and the angle of the directional character-
istic in the complex plane are specified. Refer to Appendix A
for detailed trip curve information. This protective function is
available only if the voltage input option is installed on the
relay. The associated relay subaddresses are fisted in Table
3.13.
23