Siemens 7SR12 Argus Manual page 320

7SR11 & 7SR12 Commissioning and Maintenance Guide
50SEF-3
50SEF-4
2.9.4.2 ANSI Reset
If the element is configured as an ANSI characteristic, it may have an ANSI decaying reset delay applied.
ANSI reset times from operated condition to fully reset are as follows for zero applied current and TM = 1.0. The
reset curve characteristic type and TM is defined by the operating characteristic.
Curve
ANSI-MI
ANSI-VI
ANSI-EI
Apply current in the following sequence, a) 2x setting for a time to ensure element operation, b) Zero current for
the reset time above (xTM), c) 2x setting for a time to ensure element operation. Check that the second operation
(c) is similar to the first (a) and in line with the expected operate time for the element at this current level.
Repeat the test with the reset time (b) reduced to 50% of the previous value. Ensure that the second operate time
(c) is 50% of the first (a) operate time.
Operate time Reset time
(expected) (calculated)
Check correct indication, trip output, alarm contacts, waveform record.
2.9.4.3 IEC Reset
If the element is configured as an IEC characteristic, it may have an IEC (decaying) reset delay applied.
IEC reset times from operated condition to fully reset are as follows for zero applied current and Time multiplier
(TM) = 1.0. The reset curve characteristic type and TM is defined by the operating characteristic.
Curve
IEC-NI
IEC-VI
IEC-EI
IEC-LTI
Apply current in the following sequence, a) 2x setting for a time to ensure element operation, b) Zero current for
the reset time above (xTM), c) 2x setting for a time to ensure element operation. Check that the second operation
(c) is similar to the first (a) and in line with the expected operate time for the element at this current level.
Repeat the test with the reset time (b) reduced to 50% of the previous value. Ensure that the second operate time
(c) is 50% of the first (a) operate time.
Operate Reset time
(calculated)
time
(expected)
©2017 Siemens Protection Devices Limited
Fully operated to reset with Zero current applied & TM=1 (secs)
Operate time
(measured)
First test (c)
Fully operated to reset with Zero current applied & TM=1 (secs)
Operate time 50% Reset
(measured)
Time
(calculated)
First test (c)
4.85
21.6
29.1
50% Reset 50% operate
Time time
(calculated) (calculated)
9.7
43.2
58.2
80
50% operate
time
(calculated)
50% operate
time
(measured)
Second Test (c)
50% operate time
(measured)
Second Test (c)
Chapter 6 Page 36 of 72