How To Prevent Distribution Transformers From Burning Out?

1. Reasonably select the installation location of distribution transformers
The installation of distribution transformers must meet the voltage requirements of users, and try to avoid installing distribution transformers in barren mountains and ridges, places that are prone to lightning attacks and far away from residential areas. This will not facilitate regular maintenance by operators and management by staff. .
2. Reasonably select the capacity of distribution transformers
It is also very important to reasonably select the capacity of the distribution transformer. It can neither cause the distribution transformer to be burned out due to overload, nor cause waste like a large horse-drawn cart. The capacity of distribution transformers should be reasonably selected based on user load conditions and statistical capacity. For example: a 100kV·A distribution transformer with a power factor of 0.85 can carry a load of 85kW.
3. Strengthen the measurement of electrical load
During the peak period of electricity load, the load measurement of each distribution transformer should be strengthened, and the number of measurements should be increased if necessary. Distribution transformers with unbalanced three-phase current should be adjusted in time to prevent the neutral line current from being too large and easily burning the leads. Causing user equipment to burn out.
4. Avoid installing low-voltage metering boxes on distribution transformers
Low-voltage metering boxes installed on distribution transformer areas in remote mountainous areas should be gradually removed and installed indoors as much as possible. For example, when our bureau eliminated rural areas without electricity a few years ago, in order to facilitate management and prevent power loss, low-voltage metering boxes were installed in remote mountainous areas. The metering box, due to long-term operation, the glass of the metering box is damaged or the low-voltage pile head of the distribution transformer is damaged and cannot be replaced in time, resulting in damage to the distribution transformer due to burning of the energy meter due to rain and other reasons.
5. Properly configure the high and low voltage fuse melts of distribution transformers
The unreasonable melt configuration of the high and low voltage fuses of the distribution transformer can easily cause the distribution transformer to be severely overloaded and burn out the distribution transformer. The high and low voltage melt configuration should follow: ① Transformers with a capacity below 100kV·A are equipped with fuses that are 2.0 to 3.0 times the rated current; ② Transformers with a capacity above 100kV·A are equipped with fuses that are 1.5 to 2.0 times the rated current; ③ The low-voltage side fuse should be configured with a slightly larger rated current.
6. It is not advisable to adjust the tap changer without permission
Due to the difference in electricity load between winter and summer, the voltage is slightly different. In order to meet the voltage requirements, some rural electricians adjust the tap changer at will without conducting relevant tests, resulting in the tap changer not being in place, causing a short circuit between phases and burning out the equipment.
7. Install insulation covers on top and bottom of distribution transformers
In order to prevent natural disasters and external damage, high and low voltage insulation covers should be installed in residential areas with narrow roads and forest reserves when necessary to prevent low-voltage short circuits and burning of the transformers caused by things falling on the distribution transformers.
8. Lightning arresters should be installed on both high and low voltage sides of distribution transformers.
Lightning arresters should be installed on both high and low distribution transformers in areas with multiple mines. If the quality of the arrester is not up to standard or if it fails, it is not replaced in time, and the transformer is susceptible to lightning attacks and burning out. During the thunderstorm season every year, the lightning arrester should be sent to the repair and testing department and installed promptly after passing the test. It is prohibited to use unqualified products.
9. Regularly measure the ground resistance of distribution transformers
After long-term operation (especially when the ground lead is replaced by aluminum wire), the distribution transformer is severely oxidized and the ground resistance increases. In addition, the buried ground body is corroded and broken, causing the neutral point potential to shift. When a lightning strike or overvoltage occurs, , easy to cause accidents. According to regulations, the grounding device should meet the following requirements: the grounding resistance of distribution transformers below 100kV·A shall not be greater than 10Ω, and the grounding resistance of distribution transformers above 100kV·A shall not be greater than 4Ω.
10. Strengthen daily management
Regularly inspect power lines and cut down trees to prevent branches from hitting wires, causing low-voltage short circuits and burning distribution transformers. The staff's lack of daily management of the distribution transformers caused the transformers to run without oil for a long time. The respirators were not installed or the silica gel was not replaced in time, causing the distribution transformers to get water and moisture, which could easily cause accidents. The distribution transformer itself has quality problems. Since the distribution transformer is installed far away, some construction workers put untested distribution transformers into operation without authorization to use electricity temporarily, which burned out the transformer.
11. Regularly check the low-voltage leads of distribution transformers
It is strictly forbidden to use the wire itself as a wire nose and directly connect it to the low-voltage pile head of the distribution transformer. Regularly check and strengthen the contacts between the lead wire and the distribution transformer pile head to prevent the low-voltage pile head of the distribution transformer from being burned due to looseness.
To ensure that distribution transformers operate safely for a long time and have fewer failures, as operation managers, they must perform frequent inspections, maintenance, and measurements, detect problems in a timely manner, and deal with them in a timely manner to avoid the expansion of faults and burning of the distribution transformers.