7SR224 Argus Commissioning & Maintenance Guide
©2010 Siemens Protection Devices Limited
Chapter 6 Page 31 of 73
Calculated Timing values in seconds for TM =1.0
Curve
2 xIs
5 xIs
IEC-NI 10.03
4.28
IEC-VI 13.50
3.38
IEC-EI 26.67
3.33
IEC-LTI 120.00
30.00
ANSI-MI 3.80
1.69
ANSI-VI 7.03
1.31
ANSI-EI 9.52
1.30
Note that the operate time may be subject to the
Minimum op time
setting for the element and/or may have a
Follower DTL
applied.
If VTS action is set to BLOCK, this option should be tested. Apply balanced voltage and current. Reduce a-phase
voltage to cause a VTS condition. Increase a-phase current and check that the element does not operate.
If VTS action is set to Non-Directional, this option should be tested. Apply balanced voltage and current. Reduce
a-phase voltage to cause a VTS condition. Increase a-phase current and check that the element operates at its
normal setting. Reverse the voltage phase direction whilst checking that the element does not reset.
2.7.3.1
Element Blocking
The Sensitive Earth Fault elements can be blocked by Binary Input Inhibit and VT Supervision. The Characteristic
can be made non-directional by VT Supervision. This functionality should be checked.
Element
BI Inhibits
VTS action
51SEF-1
51SEF-2
51SEF-3
51SEF-4
50SEF-1
50SEF-2
50SEF-3
50SEF-4