Curve Fully Operated to Reset with Zero Current Applied
& Tm = 1 (s)
IEC-NI 9.7
IEC-VI 43.2
IEC-EI 58.2
IEC-LTI 80
Apply current in the following sequence, a) 2 times setting for a time to ensure element operation, b) Zero
current for the reset time above (xTm), c) 2 times 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
(expected)
Reset Time
(calculated)
Operate Time
(measured)
50 % Reset Time
(calculated)
50 % Operate
Time (calcu-
lated)
50 % Operate
Time (meas-
ured)
First test (c) Second Test (c)
50GS/51GS Sensitive Earth Fault
Other protection functions may overlap with these functions during testing, it may be useful to disable some
functions to avoid ambiguity. Calculated EF, Measured EF, Sensitive EF & Restricted EF protec-
tions can be Enabled/Disabled individually or as groups in the Function Config menu.
Sensitive EF (GS) elements can be separated from Calculated EF by secondary injection of current
through the CT4 input circuit only.
If any of these elements are defined as directional the correct residual voltage phase direction will be required
to produce correct operation of the 67GS element for an operation of those elements.
The 67GS elements will normally operate on the residual current through the CT4 input but can be set to
operate on only the real (wattmetric) component of this current by setting 67GS I
res
Select to I
res
Real. If this
option is selected, the residual current and voltage should be set in anti-phase during testing to so that the
applied current is purely real and can be measured directly.
If 67GS Wattmetric is set to Enabled, the residual real power must also exceed the 67GS Wattmetric
Power setting to permit any directional 50GS element operation
Directional Polarity
See 10 Technical Data for testing details.
If 67GS Wattmetric is set to Enabled, the residual real power must also exceed the 67GS Wattmetric
Power setting to permit GS operation. As the directional boundary is approached, the wattmetric current, will
by definition reduce towards zero. It is therefore necessary to increase the residual current or to temporarily
disable the Wattmetric function to allow the directional boundary to be tested.
If the 67GS Compensated Network setting is set to Enabled, the directional boundaries will be extended
to MTA + 87° and MTA - 87°.
MTA
Forward Reverse
Lag (point C) Lead (point A) Lead (point B) Lag (point D)
Pick-up Drop-off Pick-up Drop-off Pick-up Drop-off Pick-up Drop-off
MTA -85 MTA +85 MTA -85 MTA -85
GS
Definite Time Overcurrent (50GS)
If DTL setting is small, gradually increase current until element operates.
If DTL is large apply 0.9 times setting, check for no operation, apply 1.1 times setting, check operation.
9.9.14
Functional Tests
9.9 Protection Functional Tests
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 479
C53000-G7040-C014-1, Edition 11.2019
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