What are the main physical properties of SF6 gas?
A: SF6 gas is colorless, tasteless, non-toxic, non-flammable inert gas, with excellent insulation properties, and not aging deterioration, the proportion of about 5.1 times the air.
transformer and factory transformer installed gas relay What are the requirements?
A: With the oil pillow 800kVA and above transformers, thermal power plant 400kVA and hydropower plants 180kVA and above plant transformers should be installed gas relay.
Why A-class insulation transformer winding temperature is set to 650C?
A: Transformer in operation to produce iron loss and copper loss, these two parts of the loss of all converted to heat, so that the core and winding heat, insulation aging, affecting the life of the transformer, so the international provisions of the transformer winding insulation more A-level Insulation, provides the winding temperature rise of 650C.
resistance limiting current on-load tap-changer which five main components? What are their uses?
A: The resistance limiting current on-load tap-changer composition and role as follows:
(1) Toggle switch: Used to switch the load current. (2) Selection switch: Used to switch the pre-selected tap.
(3) range switch: for commutation or coarse tap. (4) Actuator: is the power part of the tap, with interlocking, limit, counting and so on. (5) fast institutions: according to the procedures required to quickly switch.
side of the transformer tank installed thermosiphon filter What is the role?
A: The transformer oil in the operation will gradually dirty and oxidized, in order to extend the use of oil, so that the transformer in good conditions to run, you need to maintain good oil quality. A thermosyphon filter keeps the transformer oil in good working condition without severe aging. In this way, oil can be recycled for many years without special treatment.
What is the unbalanced current transformer? What are the requirements?
A: Transformer unbalanced current refers to the three-phase transformer winding current difference between the terms.
Three-phase three-wire transformer, the phase load imbalance must not exceed 20%, in three-phase four-wire transformer, unbalanced current-induced neutral current must not exceed 25% of the rated current of low-voltage winding. If it does not meet the above requirements, should be adjusted load.
transformer new or overhauled after the transformer to determine why the cover and the oil pillow connecting pipe slope? What is the standard?
A: The gas relay side of the transformer has two slopes. One is along the gas relay direction of the transformer cover slope, should be 1% to 1.5%. Transformer cover slope requirements in the installation of the transformer from the bottom pad. The other is the transformer oil tank to the oil pillow connecting pipe slope, should be 2% to 4% (this slope is manufactured by the manufacturers good). The two slopes one is to prevent the storage of air in the transformer, the second is to facilitate the fault in the gas quickly and reliably into the gas relay to ensure correct operation of gas relays.
transformer which part of the normal operation of the winding is the hottest?
A: The temperature of the windings and the core are the upper part of the lower part of the lower. The general structure of the oil-immersed transformer windings, experience has proved that the temperature of the hottest height direction of 70% to 75%, horizontal from the winding diameter of one third of the calculation, the most hot spots of each transformer windings should be determined by the test.
adjust the capacitor in the power system play a role?
A: The role of the capacitor is to transfer the system reactive power, improve power factor, reduce the loss in the network, adjust the network voltage and improve power quality have a better effect.
electrical wiring the main requirements are?
A: The main electrical wiring requirements are:
(1) has the reliability of power supply. (2) has the operational security and flexibility.
(3) simple, easy to operate. (4) with the construction and operation of the economy. (5) Consideration should be given to the possibility of future expansion.
