Specific inspection contents of transformer
Writer： Hengfeng you electric Time：2023-04-07 views：times
The transformers installed in the main substation and the 6kV substation often with personnel on duty shall monitor the operation of the transformer according to the appearance on the control panel and read the meter once an hour. If the transformer works under overload, read the meter at least once every half an hour. If the meter reading of the transformer is not in the control room, the number of meter reading can be reduced as appropriate, but it shall be recorded at least twice per shift.
The thermometer installed on the transformer shall be recorded together when inspecting the transformer.
For unattended transformers, the voltage, current and upper oil temperature of the transformer shall be recorded during each regular inspection. In addition, for the distribution transformer, the load of a three-phase shall be measured during the maximum load. If the distribution is unbalanced, it shall be redistributed. The measurement period shall be regulated in the site procedures.
External inspection of power transformer shall be conducted regularly, and the inspection cycle can generally refer to the following rules:
1. The transformers installed in the main substation and 6kV substation often attended shall be inspected at least once a day and at night once a week.
2. For substations without personnel on duty and indoor transformers with a capacity of 3200 KVA or above, they shall be inspected at least once every 10 days, and shall be inspected before and after each operation. If the capacity is greater than 330 KVA but less than 3200 KVA, it shall be checked at least once a month, and it shall be checked before and after each operation.
3. The substation without personnel on duty or the transformer of 320 KVA and below installed in the small transformer room shall be inspected at least once every two months.
According to the specific conditions of the site (dust, icing, etc.), the inspection times shall be added and set into the site procedures.
In case of drastic climate change (cold and hot), additional inspection shall be carried out on the oil level of the transformer. The transformer shall also be subject to external inspection when the gas relay announces the alarm signal.
General items for external inspection of transformer are as follows:
1. Check the oil color in the transformer conservator and the oil filled bushing (if the structure of the oil filled bushing is suitable for inspection), the height of the oil surface and whether there is oil leakage;
2. Check whether the transformer bushing is clean and free from damage, crack, discharge trace and other phenomena;
3. Check the nature of transformer buzzing, whether the sound is increased, whether there is a new tone, etc;
4. Check whether the cooling equipment works normally;
5. Check whether the cable and bus are abnormal;
6. Check the oil temperature of the transformer;
7. If the transformer is installed indoors, check whether the doors, windows and latches are intact, whether the house leaks rain, and whether the lighting and air temperature are suitable;
8. Check whether the barrier of the anti riot pipe is intact;
9. Check whether the oil level of the gas relay and the connecting throttle are open.
According to the structural characteristics of the transformer, the items that must be supplemented for inspection shall be specified in the on-site procedures.
The person in charge of electrical work of each unit shall organize additional inspection of the following items:
1. Grounding of transformer shell;
2. Breakdown regulator;
3. Operation of oil regeneration equipment and filter;
4. There are anhydrous and unclean objects in the dirt collector of the oil conservator, if any, they should be removed;
5. Ventilation of indoor transformer;
6. Use the control throttle to check whether the oil needle is blocked;
7. Whether the desiccant in the respirator has absorbed moisture to saturation;
8. Lead sealing of throttle and other parts;
9. Whether various signboards and colored paints are clear and distinct.
For forced oil circulation water-cooled transformer (this cooling method is adopted for electric furnace transformer of our company), the following items shall be checked:
1. The oil pressure in the oil cooler shall be higher than the water pressure (generally 1 ~ 1.5 atmospheric pressure);
2. There should be no oil in the water outlet of the oil cooler. If there is oil, it means that the oil cooler has oil leakage;
3. The bearings of pumps and motors must be outstanding.
For transformers that pressurize to circulate water and oil coolers, the following items should be checked:
1. Maintain the necessary water pressure, but do not exceed two atmospheres;
2. The cooling system shall not be frozen. Therefore, for transformers that are out of service in each season, all the water in the cooling system, especially in the serpentine pipe, should be drained.
