Voltech AT3600 User Manual page 152

P T
ROGRAMMING ESTS
3. Enter the number of impulses.
4. Enter the high and low terminal names. Use the mouse to pull down the menu
5. Select (mouse click the button) the type of limits you require and enter the
6. Select OK. The test specification will then be displayed in the program window.
P 3.4.46.
AGE
In AUTO mode, the tester automatically determines the ideal sample rate and
duration after testing the first sample in a batch. AUTO mode is recommended
for new test programs. If you are converting an existing test program from fixed
to AUTO surge testing mode, beware that under some conditions the measured
result may change.
Note that the Inductance value may also be entered from a measurement on the
specimen by using the Measure button.
You may choose only to have one impulse; the test will be quicker to execute,
but there will be less chance of promoting a failure in a transformer where the
inter-turn insulation is damaged and weakened, but not yet causing a complete
short. More impulses give a greater chance of detecting damaged insulation.
along side the fill-in box, and double click to select the terminal.
values.
% Enter a nominal value and then the limits as negative and positive
percentage values.
>< Enter minimum and maximum values.
> Enter just a minimum value.
It is very difficult to predict the minimum and maximum areas from theory.
A practical approach is to use the Measure Button (see section 3.9 of this
chapter):
Measure the area on a known good transformer; let this result be area A
Wrap an additional single turn round the core, short the two ends together,
and re-measure the area; let this result be area A
Set the limits as follows:
= 3
Max Area
= (
Min Area
Remember that these limits are taken from only one transformer, and may
need to be revised after more have been tested.
A 2
G
A + A ) 2
G F
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