6.3.4 Trim
If the TRIM test is included in a program, the behaviour in EXECUTE Mode is similar to the ‘Stop on Fail’ option described above:
If the test before the TRIM test produces a ‘Pass’ result, then the program proceeds directly to the next test after the TRIM test.
If the test before the TRIM test produces a ‘Fail’ result, then the front panel display will be similar to the following:
The main difference between this and the ‘Stop on fail’ display is that the reading on the fourth line will be continuously updated, allowing adjustments to be made to bring the test result within limits.
Pressing the ABORT soft-key again stops the program and allows the operator to throw away a transformer that cannot be adjusted to give a ‘Pass’ result.
After pressing the CONTINUE soft-key, the remaining tests in the program will be executed, and at the end of the measurement, the component will be classed as a ‘Fail’.
Pressing the RE-RUN soft-key will re-start the test sequence from the beginning.
Note: After making the necessary adjustments, you must press RE-RUN to enable the component to be recorded as a ‘Pass’.
If further adjustment is necessary, you may re-run from the start as many times as you like. Unless the option ‘Send Retry Results to Server’ is enabled, there will be no data sent back to the Server until the measurements for all tests in the program have been completed.
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As TRIM can only be applied to a test that uses a low voltage generator, the
safety interlocks will not be in operation while adjustments are being made.
All transformers are capable of generating voltages much higher than the test
voltage.
When making adjustments, take care not to touch any transformer terminals,
the transformer body, or any exposed metal on the test fixture. Ideally, make
sure that you use trimming tool with a well insulated handle.
When applying a test signal to a winding, always be mindful of the turns ratio of
the transformer you are testing. Very high voltages can be generated on the
other windings of the transformer, if these voltages exceed 7kV the tester may be
permanently damaged. |