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Serial No: Use the virtual keyboard to fill CT serial no. from the nameplate of the
CT under test.
Asset ID: This is a user defined field.
Phase: Can be used to identify the phase that the CT is located on
Metering or Relaying: Select the type of CT. Selection of the type of CT affects the performance
of the excitation test. Typically a metering class CT will saturate and thus have a knee point of
less than 30V. So in order to gather enough data points to calculate the knee point, if the type
of CT is set to “Metering” the MVCT will increment the voltage during the excitation by ½ V
increments. Conversely a relaying/protection class CT will saturate at much higher voltage
levels. So if the type of CT is set to “Relaying” the MVCT will increase voltage increment with
each subsequent step until the knee point is reached. This allows the MVCT to reduce the
number of data points and thus the testing time of relaying class CT. Please note that if the type
of CT is unknown then it is best to omit this selection. For if the type of CT is unknown then the
MVCT will increment the voltage by ½ V up to 30 V and then begin increasing the voltage
increment until the knee point is reached.
Saturation Standard: Select which standard will be used when testing the CT. The user can
select between the 2 ANSI methods of ANSI 45 or ANSI 30, or several different IEC methods. The
different IEC methods are IEC 60044-1; IEC 60044-6, and IEC 61869-2
Accuracy Class: Use the drop down menu to select the CT accuracy class from available options
such as
aa) C10 h) T10
b) C20 i) T20
c) C50 j) T50
d) C100 k) T100
e) C200 l) T200
f) C400 m) T400
g) C800 n) T800
VA: The VA rating of the CT can be obtained from the nameplate
Burden The Burden rating of the CT can be obtained from the nameplate
Buried CT in Delta Connection: The CT ratio is measured as ratio = Vx/Vh. However since the
induced voltage measured through the H terminals of a Delta winding is V = 2/3Vh. Thus the
measured ratio is 3/2 higher than actual ratio. By checking this box when the CT under test is in
a delta configuration, the MVCT will display the correct ratio by reducing measured ratio by 2/3
Simulated Primary Lead Swap Allows the user to simulate swapping polarity of the primary
leads. This is for report purposes only
In Service Tap: Can be sued to identify which tap is in service. This value is for report purposes
only
Actual Burden (VA): Allows the user to identify the actual amount of burden connected to the
CT. In the second page of the report, in the ratio and phase error tables, the performance of
the CT is currently evaluated with 100%, 50%, 25%, and 12.5% of the rated burden. If a value is
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