| 摘要 |
PURPOSE:To prevent the temperature of winding from exceeding a given temperature by an apparatus wherein the oil of lower temperature is mixed with an oil which flows circulating through a transformer under a heavy load to lower the oil temperature temporarily. CONSTITUTION:When a heavy load is applied during the time a cooler 6 is operated with cooling fans 7 and feeding pumps 8 in the reduced number under a light load, a judging section 12 judges that the load current of a winding 2 has increased beyond a given value. A signal from a control section 13 then causes a solenoid valve 18 to be opened. On the other hand, the outlet part of a nozzle 19 provided in a lower piping 5 has an oil passage with the reduced sectional area, so that the flow speed of oil becomes larger and the static pressure is lowered at the nozzle part. Thus, upon opening of the solenoid valve 18, the oil of lower temperature within an oil chamber 15 is attracted into the lower piping 5 through a bypass pipe 17 to be mixed with oil circulating through a tank 3 of the transformer and then sent to the winding 2 for cooling the same. |
