3.2 Testing Line Frequency Transformer
Bobbin wound transformer ;Part Number 1797 - 12VA
This transformer is tested using a plug-in fixture.
Although this transformer uses only 9 terminals, the fixture has all 10
terminals connected so that the fixture can be used with any other
transformer designed on the same bobbin.
The fixture program describes the relationship between the terminal name
on the plug-in socket and the AT SERIES node that it has been wired to. It
allows the test program that is written for the transformer, and all test
results, to refer to the transformer terminal names.
Recommended measurements for line frequency transformers
Test
|
Why?
|
| Winding Resistances |
To ensure correct wire size has been used and correct tension
during winding. Checks that transformer properly installed in test
fixture |
| Magnetizing Current and Open Circuit Voltages |
Checks for correct core material and core construction. Ensures
that operating on correct point on B-H curve. |
| Leakage Current |
Open circuit voltage tests confirm that
windings have correct turns and have
correct phasing |
| Insulation Resistance |
Only required on transformers used in
patient contact in medical applications |
| Hi-Pot |
Checks isolation between windings
Checks safety isolation
primaries to secondaries (and to core if
required) |