3. Tests

The tests to be carried out on instrument transformers are defined in IEC standards 44-1 to 44-5. However, they are generally specified in the specifications, in addition to the standards cited as references.

There are essentially two categories of test:

• individual (or routine) tests, carried out on all units;

• type testing, carried out on a single unit of each type, to demonstrate that all transformers built to the same specification satisfactorily meet the requirements not checked by the individual tests.