Transformers regulate the right flow of electricity within your premises by stepping up or stepping down the voltage as required. Such power transformers in India prove to be the lifeline of any business, and any kind of failure of these transformers means loss in production, and in turn loss of profits. This is why it is very important that these transformers are well maintained, especially when they are dry type transformers, as they don’t use any insulating liquid to cool the system, but rather use air. Thus, the windings of such dry type transformers need to be kept free from moisture at all times. If these transformers are not taken care of, and are left alone in areas where there is high humidity, dampness, or extreme fluctuations in temperature, moisture accumulates in the windings. Thus, there should be a routine inspection and maintenance schedule in place to ensure smooth functioning of your transformer.
However, there are certain precautions to be kept in mind before undertaking such maintenance. For instance, the transformer should be de-energized before conducting maintenance, and the transformer terminals should be connected to the ground. And then, before energizing the transformer again, these connections should be removed. Once you have undertaken these precautions, you can take up the maintenance procedure. And for that, here are certain tips you can follow.
As mentioned above, dry type transformers need to be kept free from moisture. Thus, there should be regular inspection for rusting, corrosion, and requirement for paint or varnishing. Also, the insulation should be checked for wear and tear, and if observed, immediate corrective measures should be taken. Auxiliary devices should also be inspected.
Windings are an important part of any transformer, which is why they must be completely checked. Check for contaminants on the insulation of the windings, or where air flow could be restricted. Loose connections, terminal boards, and tap changers should be checked. Also, checks for heating and carbonization should be made. Windings and insulators should be kept dust-free to permit sufficient circulation of air, and prevent the breakdown of insulation. Also, the vents should be cleaned appropriately. You can use a vacuum cleaner, compressed air, or blower to do the same. You can use a brush or dry lint-free cloth to clean the lead supports, terminal boards, tap changers, bushings, and every other part of the transformer and windings. Avoid using liquid cleaners.
Insulation resistance check
The moisture content of the insulation material in the transformer can be determined with this check. Transformers that are over 500kVA, with primary voltage more than 600V, malfunction due to moisture. Both primary and secondary windings should be examined for resistance between them, and between the individual windings and the ground.
Applied voltage test
The difference between the test voltage and related winding voltage should not be more than 1kV. Also, the minimum resistance readings should match the manufacturer recommendations before the transformer is energized. The presence of moisture is indicated for resistance readings less than 20,000 ohms per volt, which is measured by a hi-pot tester.
With all of the above mentioned tests, you can ensure the quality and performance of your dry type transformer. And, to maximize the potential of your transformer, make sure you purchase your dry type power transformers in Germany from a reliable manufacturer with extensive experience and engineering standards, one like Miracle Electronics.