A key question that anyone contemplating the purchase of a transformer needs to ask is whether the selected manufacturer has a facility capable of testing the product in accordance with the relevant international standards and is in possession of the correct certification.
Another important point to clarify is when was the last time that the facility was audited; this will give peace of mind that all the equipment has been correctly calibrated. It is a requirement to have test equipment calibrated and certified, annually.
You also need to enquire as to how the results of the test have been derived, and whether this is the facility’s own programme. If so, you need to find out if an independent third party has verified the programme, and specifically that it cannot be manipulated to produce favourable results.
When witnessing a factory acceptance test, it is crucial that the person witnessing these tests understands them and is able to scrutinise the results provided and not simply take them at face value.
At the end of the day, you need to know that the results correlate with what you placed an order on. Most facilities will also issue, a couple of days before witnessing the testing of the transformer, a test procedure guide.
The person witnessing these tests needs to familiarise him or herself with how the tests will be conducted, as different facilities have different procedures for testing, and whether the tests to be conducted are in accordance with the relevant standards.