Omicron Lab CT Analyzer, User Manual

Page: 87 / 254

85
The CT Analyzer Test Cards
VA *
Cos
ϕ
Nominal burden of the CT, used to calculate the behavior of the CT at the
nominal burden.
Possible values: 0 to 300VA or soft keys 1.0VA to 30VA or ?
1
.
Depending on the burden and the selected test standard, the corresponding
cos
ϕ
is used (cos
ϕ
not editable by the user).
* This parameter is relevant for assessment. No automatic assessment is
available if the user did not enter data for this parameter prior to the test (see
page 82).
If the IEEE C57.13 standard is selected with the type "metering CT", the
CT Analyzer offers some soft keys (e.g. B-0.1 , B-0.2 , B-0.5 etc.) with
standard loads for the power. If these soft keys are used, the power is
calculated according to table 9 of IEEE C57.13. If the rated current is not 5A,
the resistance and inductance of the table is multiplied by the factor
If the IEEE C57.13 standard is selected with the type "protection CT" (class
C, K or T), the VA and Cos
ϕ
parameters are not accessible to the user. In
this case, the user has to enter the terminal voltage V
b
instead. See "Specific
parameters and settings displayed for IEEE C57.13 protection CTs" on
page 98.
Burden
Cos
ϕ
"Burden" and "Cos
ϕ
" are used to define the operating burden connected to
the CT. These parameters are used to calculate the behavior of the CT at
the operating burden (connected burden) and the corresponding cos
ϕ
.
Possible values for "Burden": 0 to 300VA or soft keys 1.0VA to 30VA or ?
1
.
Possible values for "Cos
ϕ
": 0 to 1.
These parameters can also be changed after the test or in a loaded test
report in order to check the CT behavior at different burden values.
Special behavior depending on available test cards:
If the test contains a
Burden card, a question mark is automatically entered
to the fields "Burden" and "cos ϕ " and entering the burden is not possible
until the test is finished. In this case, the value determined during the burden
test is automatically entered after burden measurement. If I
sn
is defined, the
burden is updated immediately after the burden test is finished. If I
sn
is not
defined (entry "?"), the burden is updated after the resistance test.
f Rated frequency of the CT.
Possible values: Integer value between 16 and 400 Hz or soft keys
16.7Hz ,
50Hz , 60Hz or 400Hz .
Default: Frequency defined in the default test settings.
Parameter Description
α
5
I
rated
-------------
 
 
2
=