Operation and maintenance of the Dry Type Transformers
Environmental requirements for cast resin dry-type power transformer operation:
rainproof, moisture-proof and dust-proof, to prevent the intrusion of harmful gases and small animals. There should be effective ventilation and heat dissipation conditions for the transformer. Especially in the season of high temperature, should pay attention to the reduction of indoor temperature. Ventilation is selected according to loss per kw (P0+PK) 3 ~ 4m3/min. Kw.
The temperature around the transformer should not exceed 40℃ in a closed space (i.e. inside the transformer housing), and the air relative humidity should not exceed 95% during operation. For hot and humid coastal areas, basements and poorly ventilated transformer operation, it is recommended to install air-conditioning dehumidification and cooling in the transformer room.
When adjusting the gear of the transformer, if it is a non-excitation voltage regulation, the high and low voltage power supply of the transformer should be cut off, and the grounding wire should be connected. The three coils should be adjusted to the same position simultaneously. If the output voltage is required to decrease, adjust to the first gear, and if the output voltage is required to increase, adjust to the n gear. At the same time, pay attention to the tightness of the gear screws. If they are not tight in place, the terminal will easily be burnt due to discharge. If it is too tight, the screws will be broken. So have a feel. The recommended output voltage is 390～400V.
Parallel operation of transformers. Three conditions must be met: the input and output voltages are the same; the connection group is the same; the impedance voltage difference is not more than 10%. (It is better to have similar capacities.) The phase sequence is found to be incorrect before it is put into operation. Generally, the user reverses the low-voltage or high-voltage wiring. The measurement of the connection group of our company has to be repeated several times before leaving the factory, and it should be guaranteed. The transformers manufactured by our company have not found any wrong connection group. Unless the user changes the factory state of the transformer.
Transformer maintenance notice: transformer thermometer general Settings: start the 100 ℃ the fan and fan stop 80 ℃, 130 ℃ alarm and trip 150 ℃. (F class insulation temperature 155 ℃) to allow for maximum dry transformer insulation shall be maintained during shutdown and guaranteeing. The starting temperature of the fan should not be lowered, otherwise the fan may be damaged easily and increase energy consumption.
Varelen Electric Co., Ltd