Successful Maintenance of Transformers at Coca-Cola Kwanza

At Industrial Automation and Electrical Systems, we understand that reliable power is critical to the success of any operation. Recently, our team completed a comprehensive preventive maintenance project for Coca-Cola Kwanza Company Limited in Dar es Salaam, ensuring their transformers remain in optimal condition. This article provides an in-depth look at the steps involved in this service. This shows our commitment to maintaining optimal transformer performance and reliability.

The preventive maintenance for the transformers was carried out from March 25 to March 26, 2023. This involved the inspection, cleaning, and a series of electrical tests on four transformers, each with specific details and requirements. The transformers, manufactured by TSS, included models with capacities of 1000 KVA, 1250 KVA, and 2000 KVA. By detailing the procedures and practices followed during the servicing, we aim to highlight the importance of regular transformer maintenance and its impact on industrial productivity and safety.

How we did it

Our team began with a thorough visual inspection of the transformers. This included checking the tank, radiators, and bushings for oil leaks or damage. We also inspected transformer accessories such as conservators, breathers, and Buchholz relays. During the inspection, we noted some issues such as saturated silica gel in the breathers and oil leaks due to improper tightening.

To address these issues, we replaced the old silica gel in all transformer breathers and tightened the rubber gaskets in the Buchholz relay junctions and HV bushes to prevent oil leakage. We also ensured that the transformers and their accessories were clean and free from debris, dirt, and moisture. This general cleaning is crucial in maintaining the transformers’ performance and longevity.

In addition to the physical inspection and cleaning, we conducted a series of electrical tests to assess the health of the transformers. These tests included winding ratio tests to ensure no short circuits in any windings. Winding resistance tests to check the quality and condition of the windings. Insulation resistance and polarization index tests to measure the strength of the insulation. We also verified the proper operation of the Buchholz relays and conducted transformer earthing resistance tests to ensure the safety of the transformers.

One of the critical tests performed was the oil breakdown voltage (BDV) test, which assesses the dielectric strength of the transformer oil. All transformers passed this test, indicating that there was no immediate need for oil filtration. The service confirmed that all transformers were in good operating condition. We recommended regular testing of transformer oil dielectric strength and dissolved gas analysis every six months. Additionally, we suggested annual earth resistance testing as part of the preventive maintenance plan.

Conclusion

By addressing minor issues and performing essential maintenance tasks, we have significantly reduced the risk of unexpected failures. Regular maintenance and testing are crucial for sustaining the transformers’ performance and preventing downtime.