DOC. MIE11110 Rev. 5
Page 12 of 110
be measured also generating current; however, with this
connection it is also possible to test the excitation curve.
The following table explains the AC voltage output to be used as a
function of CT parameters.
Given:
. VA = VA rating;
. IS = secondary current;
. KN = overload factor,
compute:
VSM = VA * KN / IS
And then VSM/2, that is the maximum test voltage, so that we
keep away from saturation and the related errors. Note that at
the saturation there is usually 1 V per turn; more rarely 0.5 V per
turn.
The test voltage range is the following.
VSM/2
< 80 V
80 TO 220 V
> 220 V
V RANGE
90 V
250 V
3000 V
The voltage input range is also selected as a function of the test
voltage and of the CT ratio.
Given:
. KCT = CT ratio;
. VP = voltage at primary,
Then, compute:
VP = VSM / (2 * KCT)
If VP > 10 V, then connect the CT’s primary to the 600 V
measurement input, else connect it to the 10 V measurement
input.
The connection diagram is the following.
Summary of Contents for T2000
Page 1: ...DATE 18 11 2009 DOC MIE11110 REV 5 T 2000 APPLICATION GUIDE ...
Page 45: ...DOC MIE11110 Rev 5 Page 45 of 110 ...
Page 81: ...DOC MIE11110 Rev 5 Page 81 of 110 2 Selection time about 30 ms LTC fails ...
Page 83: ...DOC MIE11110 Rev 5 Page 83 of 110 4 Same LTC as above fault on this selection ...
Page 91: ...DOC MIE11110 Rev 5 Page 91 of 110 The connection diagram is the following ...
