
EN_FANOXTD_GUIDE_SIL_OCEFPrimaryDist_SILA_R002.doc 34 / 36
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51N/G Inverse time neutral overcurrent protection:
TEST 1
Settings:
-
Function Enable: YES.
-
Curve: IEC Inverse.
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Dial (TMS): 0.05
-
Current Tap: 0.3xIn.
-
Theoretical tripping time= 3.67 seconds (Fault current 0.33A)
The following information will be checked
:
-
Pick-up at 110% of the tap
-
Output 4 is activated
-
LED 3 is activated
TEST 2
Settings:
-
Function Enable: YES.
-
Curve: IEC Inverse.
-
Dial (TMS): 1
-
Current Tap: 0.3xIn.
-
Theoretical tripping time = 5.75 seconds (fault current 1A)
The following information will be checked:
-
Pick-up at 110% of the tap
-
Output 4 is activated
-
LED 3 is activated
TEST 3
Settings:
-
Function Enable: YES.
-
Curve: IEC Inverse.
-
Dial (TMS): 1.
-
Current Tap: 0.3xIn.
-
Theoretical tripping time = 2.97seconds (Fault current 2A)
The following information will be checked
:
-
Pick-up at 110% of the tap
-
Output 4 is activated
-
LED 3 is activated
Note: In TEST 2 and TEST 3 for 51 and 51G, fault current will be injected the directly to
check the theoretical tripping time. Take into account this, time is calculated through an
equation and this time depends on the injected current, so doing a ramp is possible but
the theoretical tripping time will not be checked.