Iec Reset - Siemens 7SR18 Solkor Manual

7SR18 Commissioning & Maintenance Guide
3.3.3
IEC R
ESET
If the element is configured as an IEC characteristic, it may have an IEC (decaying) reset delay applied. If IEC
reset is selected for an IEC characteristic element, the reset will be instantaneous.
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
time (calculated)
(expected)
Check correct indication, trip output, alarm contacts, waveform record.
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Fully operated to reset with Zero current applied & TM=1 (seconds)
Operate time 50 % Reset
(measured) Time
(calculated)
First test (c)
9.7
43.2
58.2
80
50 % operate 50 % operate time
time
(calculated)
Second Test (c)
©2018 Siemens Protection Devices Limited
(measured)