Restricted Earth Fault (64H); Figure 2-10 Restricted Earth Fault - Siemens 7SR21 Manual

2.9

Restricted Earth fault (64H)

Voltage Inputs:
Current Inputs:
Disable:
Map Pickup LED:
The setting resistance should be measured and the value compared to that specified in the settings data. Both
values should be recorded.
Settings Data Resistor Value
The high value of setting resistance R will often interfere with secondary current injection when using a digital test
set. It is normal practice in these cases to short out the resistor to allow testing, the shorting link should be
removed after testing.
Since the DTL setting is generally small the pick-up setting can be tested by gradually increasing current until
element operates. The relay should be disconnected from the current transformers for this test.
©2010 Siemens Protection Devices Limited
7SR21 & 7SR22 Argus Commissioning and Maintenance

Figure 2-10 Restricted Earth Fault

n/a
I (I )
5 REF
51SEF, 50SEF, 79
64H - Self Reset
Measured
Chapter 6 Page 37 of 69