For transformers with forced oil circulation air cooling, water cooling and water cooling, when the cooling system (referred to as fan, submersible pump, cooling water system, etc.) fails and the cooling device is deactivated, the following treatments shall be carried out:
(1) When the light word signal of "cooling device working power failure" or "standby power supply failure" appears on the transformer control panel, the cause should be immediately identified to enable the cooling device to resume operation as soon as possible.
(2) When the "cooling water interruption" optical word signal appears on the transformer control panel, the cause should be quickly checked to restore the cooling device to work.
(3) If the above two fault signals appear at the same time, attention should be paid to changes in the oil temperature and oil level of the upper layer of the transformer. When all the cooling devices are shut down, there will be a sharp rise in oil temperature and the possibility of running oil from the explosion-proof pipe (or safety air passage). When the cooling device resumes operation, the oil level of the oil pillow drops sharply again, and the oil level drops below the scale -20 ℃ and there is a continuing downward trend, the heavy gas protection device should be immediately disabled. If the cooling device cannot be returned to operation within the specified time, the value should be reported and the transformer should be taken out of operation.