Testing and Other Equipment

Testing of Three-Phase MT/BT Transformers and Other Equipment

Brollo Siet conducts instrumental tests to verify the proper functioning of components, reduce potential anomalies, and prevent service interruptions.

Tests on MT/BT transformers are a set of tests performed in accordance with the CEI EN 60076 standard, carried out on new, refurbished, and repaired transformers. Tests on medium-voltage three-phase transformers can be performed during normal operation to ensure correct functionality and allow timely intervention to prevent service interruptions.

Some tests can also be conducted at the customer's site without moving the transformer.

After the tests, a test report is issued.

The insulation test on MT cables with a test voltage of up to 80kV is carried out following the procedures indicated in paragraph 8.3 of the CEI 11-17 standard. According to this standard, all MT cables in a system must undergo a test after installation to ensure that the accessory assembly is defect-free or that the cables have not been damaged. The test can be performed on cables that have been de-energized for a long time, for periodic checks, or after performing joints or modifications to the MT network.

We also calibrate the relay with a certified box, mandatory for MT cabins and energy production plants. Following the test, a certified test report is issued according to CE 016, which must be conducted annually. For the test, a letter from the local distributor indicating the maximum thresholds to be inserted into the relay associated with the general protection of the electrical cabinet and the calibration values chosen by the system or medium-voltage cabinet designer is required.

We also conduct tests on MT switches, specifically:

•  Measurement of opening/closing times
•  Measurement of voltage drop across poles
•  Measurement of pole insulation