3.4.32 Magnetizing Current
Magnetizing current is measured by applying an ac test voltage to the selected winding, and measuring the resulting current.
You may program the test to use either an rms, or a mean-sense (rms scaled) type of measurement to obtain a value for the current. Normally, an rms measurement is preferred, but the mean-sense measurement is also available as it is used by some low cost multi-meters.
On selecting ‘MAGI Magnetizing Current’ from the available tests window, a form fill-in dialogue box will be displayed:
To program the test :
- Enter the voltage and frequency limits (refer to Chapter 7 - ‘Test Conditions’ which lists recommended test conditions if required).
Note that the Measure button cannot be used to determine any of the required test parameters.
- Select (mouse click the button) the type of measurement you require - RMS or Mean sense. If in doubt, see chapter 7 for more information.
- Select (mouse click the button) the integration time you require.
'Medium' is the default setting. 'Long' will give more stable readings (for tighter limits) at the expense of an increased test time, and 'Short' will test at the maximum speed, but may give a slightly noisier reading.
- Enter the terminal names for the High and Low Terminals.
Click on the arrow to the right of the fill-in box and you will be provided with a choice of the available terminals. Click the required terminal.
- Select (mouse click the button) the type of limits you require and enter the values.
>< Enter minimum and maximum values.
< Enter just a maximum value.
Note that the Measure button may be used here as outlined in section 3.9.
- Select OK. The test specification will then be displayed in the program window.