Mine distribution transformer routine maintenance
Manufacturers of mining distribution transformers not only manufacture transformers, but also maintain transformers. If the mining transformer is not maintained, it cannot exert such important performance and characteristics. The management of the distribution transformer is also part of the normal work.
ZTELEC offers five recommendations for the performance and manufacturing process of integrated mining transformers:
I, capacity
In normal operation, the power load of the mining transformer should be about 75-90% of the rated capacity of the mining transformer.
II, temperature
The thermometer installed on the mining transformer shall be recorded at the same time when inspecting the mining transformer. The unattended mining transformer shall record the voltage, current and upper oil temperature of the mining transformer at each periodic inspection. In addition, for distribution transformers, the load of a certain three-phase should be measured during the maximum load. If the distribution is unbalanced, it should be reassigned. The period of measurement shall be specified in the on-site procedures.
III. Insulation monitoring
The three-phase transformer for mining shall be measured for the insulation resistance of the coil before it is put into operation after installation or maintenance (usually after drying) and after long-term deactivation. The measured value and the oil temperature during the measurement shall be recorded in the history of the mining transformer. In the card. The insulation resistance of the measuring coil should be a megohmmeter of 1000 to 2500 volts. The allowable value of the coil insulation resistance is not specified.
The ratio of the insulation resistance value measured during the use of the mining transformer to the value measured before the mine transformer is put into operation after installation or overhaul is the main basis for judging the insulation state of the mining transformer. The insulation resistance should be measured at the same temperature as possible, using the same megohmmeter of the same voltage.
IV, current range
The maximum unbalance current of the dry-type transformer should not exceed 25% of the rated value; the allowable range of the transformer transformer power supply voltage is plus or minus 5% of the rated voltage. If this range is exceeded, the tap-changer should be used to adjust the voltage to the specified range. (The power should be cut off during adjustment.) It is usually to change the position of the winding tap of the winding to realize the voltage regulation. The device for connecting and switching the position of the tapping tap is called the tap changer, which is adjusted by changing the number of turns of the high voltage winding of the mining transformer. Variable ratio. The low voltage has no effect on the mining transformer itself, only reduces some output, but has an impact on the electrical equipment; the voltage increases, the magnetic flux increases, the core is saturated, the core loss increases, and the temperature of the mining transformer increases.
V, overload
Special circumstances mining transformers can be overloaded in a short period of time, but should not exceed 30% of rated load in winter and 15% of rated load in summer. In addition, the overload capacity of the oil-immersed transformer should be determined based on the temperature rise of the mining transformer and the manufacturer's specifications.
Mine transformer manufacturers should focus on doing this, otherwise the management of mining transformers will be affected. Since the mining transformer is a special kind of electrical equipment, it should be actively managed, so that the performance will be maintained permanently. In many cases, the mine transformer will be faulted from these aspects.
ZTELEC specializes in the production of mining distribution transformers, energy saving, safety and explosion protection.
ZTELEC offers five recommendations for the performance and manufacturing process of integrated mining transformers:
I, capacity
In normal operation, the power load of the mining transformer should be about 75-90% of the rated capacity of the mining transformer.
II, temperature
The thermometer installed on the mining transformer shall be recorded at the same time when inspecting the mining transformer. The unattended mining transformer shall record the voltage, current and upper oil temperature of the mining transformer at each periodic inspection. In addition, for distribution transformers, the load of a certain three-phase should be measured during the maximum load. If the distribution is unbalanced, it should be reassigned. The period of measurement shall be specified in the on-site procedures.
III. Insulation monitoring
The three-phase transformer for mining shall be measured for the insulation resistance of the coil before it is put into operation after installation or maintenance (usually after drying) and after long-term deactivation. The measured value and the oil temperature during the measurement shall be recorded in the history of the mining transformer. In the card. The insulation resistance of the measuring coil should be a megohmmeter of 1000 to 2500 volts. The allowable value of the coil insulation resistance is not specified.
The ratio of the insulation resistance value measured during the use of the mining transformer to the value measured before the mine transformer is put into operation after installation or overhaul is the main basis for judging the insulation state of the mining transformer. The insulation resistance should be measured at the same temperature as possible, using the same megohmmeter of the same voltage.
IV, current range
The maximum unbalance current of the dry-type transformer should not exceed 25% of the rated value; the allowable range of the transformer transformer power supply voltage is plus or minus 5% of the rated voltage. If this range is exceeded, the tap-changer should be used to adjust the voltage to the specified range. (The power should be cut off during adjustment.) It is usually to change the position of the winding tap of the winding to realize the voltage regulation. The device for connecting and switching the position of the tapping tap is called the tap changer, which is adjusted by changing the number of turns of the high voltage winding of the mining transformer. Variable ratio. The low voltage has no effect on the mining transformer itself, only reduces some output, but has an impact on the electrical equipment; the voltage increases, the magnetic flux increases, the core is saturated, the core loss increases, and the temperature of the mining transformer increases.
V, overload
Special circumstances mining transformers can be overloaded in a short period of time, but should not exceed 30% of rated load in winter and 15% of rated load in summer. In addition, the overload capacity of the oil-immersed transformer should be determined based on the temperature rise of the mining transformer and the manufacturer's specifications.
Mine transformer manufacturers should focus on doing this, otherwise the management of mining transformers will be affected. Since the mining transformer is a special kind of electrical equipment, it should be actively managed, so that the performance will be maintained permanently. In many cases, the mine transformer will be faulted from these aspects.
ZTELEC specializes in the production of mining distribution transformers, energy saving, safety and explosion protection.