The normal operation of 300kva transformer is of great importance to the electrical system. Different maintenance methods should be used to ensure their stable operation and extend their service life.
Daily inspections are essential. The appearance of the 33kv transformer must be checked daily for any oil spills or spills from the housing. Also check for clear and complete labels and markings and for deformations, damage or corrosion of the cover. Operating noise should be heard at least once a week. It is normally a uniform zoom. Abnormal noises can indicate internal defects and can be assessed using an acoustic detection device. The pressure gauge and oil pressure gauge must also be checked daily. The oil temperature should be within the normal range and the oil level should be between the upper and lower limits.
Regular maintenance should be carried out according to the plan. 300kva pad mount transformer oil immersed in the oil should be sampled and tested every six months or one year. Evidence includes dielectric strength, dielectric loss factor, water content, etc. The quality of the oil must be purified or replaced on the basis of the test results. The insulation resistance test shall be carried out at least once a year. After adjustment of the power and all the connecting wires, the insulation resistance between the windings and between the winding and the ground is measured respectively. Isolation status should be assessed by comparing test results. The strength test of the dc winding is carried out every one or two years. The imbalance rate is calculated. If it exceeds the specified value, the winding is checked in detail. In the case of air-cooled transformers, the operation of the fans is controlled and the radiators and other components are cleaned monthly. In the case of transformers with forced cooling of the oil circulation, the operating condition of the oil pump must also be checked.
Maintenance in special situations cannot be neglected. After overload, oil temperature, level and noise should be monitored over time. Isolation resistance and direct current resistance of the winding occur. Determine whether or not to repair based on test results. After short circuit shock, the outdoor dry type transformer should be stopped immediately for inspection. Emphasis is placed on the deformation of the winding and the condition of the iron core. After a full inspection, the components should be repaired or replaced according to the degree of failure to ensure safe operation of the transformer in the future.