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2.1
Measured Earth fault (50G)
Current Inputs:
Disable:
Map Pickup LED:
Other protection functions may overlap with these functions during testing, it may be useful to disable the
Restricted Earth Fault function to avoid ambiguity. This can be Enabled/Disabled in the 'Function Config' menu.
2.1.1
Definite Time Overcurrent
If DTL setting is small, gradually increase current until element operates.
If DTL is large apply 0.9x setting, check for no operation, apply 1.1x setting, check operation
Apply 2x setting current if possible and record operating time
Input
Is
(Amps)
I
G1
Check correct indication, trip output, alarm contacts, waveform record.
2.1.1.1
Element Blocking
The Measured Earth Fault elements can be blocked by Binary Input Inhibit, VT Supervision and Inrush Detector
operation. The Characteristic can be made non-directional by VT Supervision. This functionality should be
checked.
Element
50G-1
50G-2
Check correct indication, trip output, alarm contacts, waveform record.
©2013 Siemens Protection Devices Limited
Chapter 6) 7SR23 DAD Commissioning & Maintenance Guide
Figure 2-1 Measured Earth Fault
I
G
87REF
50G-n - Self Reset
(50G)
DTL
P.U. Current
(sec)
Amps
BI Inhibits
Operate Time
2 x Is
Inrush Detector
Chapter 6 Page 13 of 26
NOTES
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