Humidity: No accessibility must certanly be allowed to the transformer liquid-filled area in problems of excessive moisture or rain. If moisture exceeds 70% as an example, dried air should really be consistently excited into the gasoline space. Liquid-filled transformers that are shipped with Nitrogen in the gasoline space should be purged by putting dry air for at the least 30 minutes before company workers may enter the tank. Oxygen concentrations of 19.5% to 23.5% are advised. Examination and filling: You must produce a final examination of the transformer.
Liquid Examination: If the insulating fluid for inspection needs to be attracted down, be sure you have gear for clear and dried storage of the water all through examination and for filter the fluid prior to refilling the tank. It is transformer vital that most related gear used in the handling of the water (hoses, pushes, etc.) may also be very clear and dry. If this gear was applied before with an alternative form of liquid, clean all contaminated items. When you eliminate the water, its level should not move below the most truly effective of windings.
Force Preservation: Liquid-filled transformers might be saved outdoors upon delivery. Adequate fuel pressure must be preserved to allow a positive force of just one psi to 2 psi at all times, also at minimal ambient temperature. The pressure-vacuum gauge, if provided with the transformer, will display stress modifications with ambient temperature. Stress and ambient heat numbers must certanly be noted regularly. The manufacturer's recommendations must certanly be referred to for storage of accessories.
Filling: After applying complete voltage, the transformer must be kept below remark throughout the first several hours of operation under load. After several times, always check the fat for oxygen material and dielectric strength. All temperatures and difficulties ought to be tested in the transformer tank all through the first week of operation. Except for specific types, transformers may be operated at their rated kVA if the average normal heat of the cooling air doesn't exceed 86'F in any 24-hr period, and the height doesn't exceed 3300 ft.
