NDB Technologies CTT Series User Manual page 47

C T T S e r i e s - U s e r M a n u a l
11.1.1 Voltage Set Too High
Using the same example CT requiring only 400V to saturate its largest ratio, only
this time max test voltage was set to 2000V. This has for effect of reducing the
instrument's accuracy while plotting the saturation graph. This lack of resolution
will influence the accuracy of the ratio readings. It is worth noting this will not
damage the CT or the CTT instrument in any way, because the CTT has a built-in
distortion/crest factor detection circuit that will limit the test voltage output to
prevent applying excessive voltages and risking over saturation of the CT.
11.1.2 Voltage Set Too Low
Using once again the same example CT requiring 400V to saturate its largest ratio,
only this time max test voltage was set to only 200V. This has for effect of reducing
the range of voltage in which the instrument is able to saturate the CT. In this
example, the instrument wasn't able to saturate the CT for any of the ratios. The
ratio test and saturation tests are then invalid. It is worth noting this will not damage
the CT or the CTT instrument in any way, only the test results will be altered.
47