2.1 CTY - Continuity
Where Used
The continuity
test is available to be placed as the first test in the program to check
that the transformer has been inserted correctly into the test fixture.
The test checks
that every winding has a resistance less than a user specified limit,
with the same limit being applied to all windings. The CTY test is an
alternative to using an R (Winding Resistance) test on each winding
separately.
The CTY test
has the advantage of speed of execution; but with the R test, individual
limits can be applied to each winding, and manufacturing faults such as
the use of the wrong wire gauge can be identified.
If
you choose to use it, the continuity test will be quicker to execute
than a series of resistance tests applied to each winding
Specifying the Test Limit
When specifying
the test limit, remember that the same limit is applied to each winding,
so you must choose a value higher than the resistance of the biggest
winding.
For most
transformers, where the winding resistances are less than 1 kW, a test limit of 10 kW should be used, as this will give the
quickest test execution.