Low temperature and dry air in winter are conducive to the normal operation of electrical equipment, but at the same time, strong wind, heavy snow, ice, condensation and other phenomena in winter will also bring many unsafe factors and pose a great threat to the safe operation of electrical equipment.

Problems easily existing in the operation of electrical equipment at 0 ° C

1. The distribution cabinet and console are easy to cause condensation and frost under low temperature environment.

2. The movable electrical tool cable, the cable moving on the equipment drag chain or the air duct becomes hard and brittle at low temperature, which is easy to break, resulting in electric leakage and air leakage.

3. The capacitive screen and LCD screen of the equipment are easy to fail and misoperate at low temperature.

4. The programmable controller on the equipment (such as PLC and its module) working below 0 degree is easy to cause non operation, alarm or damage to the module.

5. The industrial computer on the equipment will restart the system under low temperature environment, damage the equipment and cause product quality problems.

6. Water is stored in the filter in the air source processing element, which is easy to cause icing and cracking.

7. There is water and ice in the pressure gauge, flowmeter and drain valve group of each pipeline, resulting in water and air leakage, which will damage the seal, etc.

Cold and antifreeze measures for electrical equipment

1、 Inspection of oil filling equipment

When the temperature of oil filled equipment such as transformer changes dramatically, the volume of oil will also change greatly. When the temperature drops suddenly, the oil level of oil filling equipment may be lower than the operation requirements, resulting in misoperation of transformer gas protection or equipment failure, resulting in accidents. Similarly, due to the change of air temperature, the sealant pad of oil filling equipment may expand and contract, and oil leakage may occur. Maintenance shall be arranged according to the situation. Frequently check whether there is oil leakage at the section switch, pressure valve and high and low voltage bushings of the transformer, and timely fasten and fill with oil. Strengthen the oil level inspection of oil filling equipment, find problems in time and deal with them as soon as possible, so as to ensure the safe operation of transformer and avoid accidents.

The key inspection contents of oil filling equipment in winter include: oil level, oil color, leakage, etc. it is found that the oil level is low, oil color changes, leakage, abnormal sound, body heating, etc.

2、 Motor

1. When the high-power motor runs in winter, the rear bearing temperature is very low and it is not easy to form oil film, so it should be refueled in time. When reversing, the operator shall timely notify the maintenance electrician. When the temperature changes sharply, the oil shall be replenished to the large motor in time.

2. The operating and standby motors generally add lubricating grease once according to the oil filling cycle.

3. Pay attention to oil leakage of bearing bush motor and replenish oil in time.

4. The motor is moisture-proof during maintenance in winter. During maintenance after shutdown, it is easy to produce condensate due to the great difference between the motor temperature and the ambient temperature, especially the motor terminals and leads. Wipe them clean to prevent three-phase short circuit.

5. Motors with long maintenance cycle such as fans and ice machines shall be overhauled in winter.

6. The motor housing shall be protected against corrosion.

7. If the process equipment freezes in winter, pay attention to prevent overload from burning the motor.

8. The existing testing instruments are used to monitor the on-line motor, and the equipment exceeding the standard is found for maintenance.

9. Pay special attention to the equipment with known defects and problems, and take compensation measures in time when changes are found.

10. Focus on checking whether all parameters of the accident generator are normal, and put the water jacket heater into operation in time to ensure emergency standby.

12. Observe the oil level of the oxygen pump motor according to the temperature change. When the oil level is low, add oil in time.

12. During motor maintenance, protection effectiveness test and circuit fastening shall be carried out.

3、 Distribution room

1. As the temperature gradually decreased, mice and other small animals began to move to the house. Prevent small animals from entering the substation in advance, repair and replace the damaged door and window glass of the distribution room and transformer room in time, block the holes in time to prevent small animals from entering, check the rat proof board and hole blockage of the distribution room, and pay attention to closing the door when entering and leaving the high and low voltage distribution room.

2. After snowing in winter, the substation shall be checked for water leakage in time. If there is water leakage, it shall be handled in time to prevent rain water from falling on the distribution board and switch collapse and burning accident.

3. The fire extinguishers in the distribution room and transformer room are in good condition and within the validity period.

4. Prevent heat tracing steam, heating and drainage, sewage steam, etc. from entering the distribution room.

5. When the temperature drops suddenly, pay attention to detect the heating of the connecting screw.

6. Pay attention to check the temperature measurement display of the contact of the high current switchgear, and deal with the problems in time.

4、 Cables, cable trays and overhead electrical facilities

1. In windy weather, the cover of cable tray and tray shall be inspected in time, and hidden dangers shall be handled in time.

2. Check the high-altitude equipment such as pipe gallery to prevent falling off.

3. Pay attention not to step on the cable during the operation of reconstruction and expansion projects (the cable sheath is easy to be damaged in winter).

4. When climbing the ladder in winter, pay attention to anti-skid, anti freezing and falling prevention.

5. After winter, check the cable joint and external power supply to prevent the joint from heating and damaging the cable.

5、 Relay protection and power electronic facilities

1. Strengthen patrol inspection, timely find the changes of operation parameters and test values, and analyze the faults, defects and hidden dangers existing in equipment operation.

2. Combined with the faults occurred in winter over the years, prevent them in advance.

6、 Site electrical facilities

1. In winter, the temperature in the electrostatic precipitator incubator is low, which is easy to cause condensation of porcelain cylinder, affect the dust removal effect and damage the equipment; Check the electrostatic precipitator incubator, block the air leakage holes, strengthen the patrol inspection of the electrostatic precipitator and electric heating system, and deal with the faults of the electric heating system in time.

2. For the electric door that is not opened and closed frequently, the opening and closing test shall be carried out during maintenance; Before startup, the operator shall pay attention to whether the motor mechanism trips due to freezing of the shut-off door. After tripping, it is forbidden to send power again for trial operation without manual switch test.

3. In winter, when it is foggy and snowy, it is necessary to prevent creepage and arrange live cleaning.

7、 Strengthen the inspection of outdoor power box, distribution panel and cabinet

Outdoor power distribution equipment is easy to accumulate water vapor and condense when the temperature decreases, resulting in the reduction of the insulation level of electrical components and the collapse and burning of equipment. It is necessary to strengthen the management of on-site direct operation links, especially the inspection of on-site temporary power consumption. The temporary power boxes of some construction units are not well sealed. In order to prevent wind and snow, they are wrapped with plastic cloth. In severe winter, the temperature difference inside and outside the temporary power box is large, which is easy to form condensation, and it is very easy to have short circuit and collapse burning accidents.

In winter, there is a lot of steam discharged from the production unit, which may string into the nearby switch control box to reduce the insulation performance of electrical components. Check whether the door of the switch control box is tightly closed and whether the fastening bolts are complete and fastened.