All the equipment in the use of aging phenomenon, there is a process of deterioration. This is obvious in mechanical equipment, but it is difficult to observe in electrical equipment.
So for the electrical system, how to extend the life cycle of equipment stable operation as far as possible? In today's article, we will discuss the impact of temperature and dust on the operation and maintenance of electrical equipment.
For motor, transformer, reactor and other equipment can be observed by temperature, electrical characteristics such as the resistance of the coil itself, insulation resistance to the ground, current changes, but the deterioration of electronic equipment is difficult to monitor. Therefore, electrical equipment needs to pay attention to daily maintenance, reduce or even eliminate the occurrence of accidents. Equipment maintenance is divided into online maintenance and offline maintenance. Some large equipment needs online maintenance. If conditions are available, it is best to replace the small and medium-sized equipment after offline maintenance.
During the use of electrical equipment, temperature and dust are fatal hazards to electrical equipment.
High temperature damage to electrical equipment
High temperature may damage the insulation of electrical equipment, resulting in short circuit or grounding, and directly burn the equipment. The heating of electronic equipment is caused by power components, mainly diode, thyristor and so on. There are usually cooling fans, and some large equipment is also cooled with water.
Causes of high temperatureThe high temperature is mainly caused by the heating of the equipment itself and the high ambient temperature on site.
The rated load of the equipment shall be exceeded during the use of the equipment
The aging of mechanical equipment will also lead to excessive load of electrical equipment
The equipment is impacted by high current, resulting in equipment deterioration over time
Loose bolts in wiring parts of electrical equipment lead to false contact, resulting in heat.
The heat dissipation device fails, and the temperature rises.
2. General treatment
Install thermal protection device, overcurrent protection device, so that in the occurrence of overload can be stopped in time
Daily observations of current and temperature need to be recorded in real time for easy analysis.
Find out the high current (relative to the rated value), high temperature equipment, in the shutdown of its key inspection.
For motor and reactor, the resistance and insulation resistance of key equipment are measured when the machine is shut down.
Record the measured values and make a chart or curve to detect deterioration.
According to the actual production situation, the fan heat equipment should be replaced regularly and maintained after offline.
When the equipment is down, the heat dissipation position should be tested.
In the process of spot inspection, it is necessary to measure the temperature with a temperature measuring gun. If the temperature rises, it is necessary to stop the machine in time.
Dust damage to electrical equipment
Now many factories are implementing the point inspection system, which is especially important for electrical equipment cleaning.
Dust affects the heat dissipation of the device.
The dust contains metal particles that attach to electronic components and cause short circuits directly.
Although most of such equipment is installed in the distribution room, but there will be dust into it. Dedusting and cleaning of electronic equipment should be carried out regularly during daily maintenance.
1. Online dust removal and maintenance of electronic equipment
For example, frequency converter, first cut off the power supply in the shutdown state, wait 2-3 minutes, after the discharge can be operated. The dust can be blown out by sticking the rubber hose of the hair dryer into the device. The dust on the power part and the cooling fan is the most. If necessary, open the enclosure of the device and blow the circuit board and silicon directly. It is important not to touch the components inside. This step should be done by a professional.
2. Online dust removal and maintenance of motor and transformer
The air quality is not good, and dust will be brought into the motor
After the motor carbon brush wear powder will also enter the motorOrdinary fan wind low, it is difficult to clean up, to use compressed air to purge.
During the maintenance of the motor, the carbon brush should be replaced regularly. It is necessary to pay attention to the direction of the carbon brush and try to replace it in batches at the same time.
The tip of the new carbon brush should be worn off in advance according to the radian of the commutator, and the pressure of the top spring should not be adjusted at will.
Summary and Case
The maintenance of equipment must form a special record ledger, the responsibility to the people, can not become a formality. The maintenance of equipment can only be done well if the work is done carefully.
Insulation Resistance Telemetry Record
Equipment Replacement Book
Equipment Cleaning and Dust Removal Stand Book
Inspection Record
Equipment Test Record
The above is some experience in equipment maintenance, which needs to form a normal mode in daily production, so that data is recorded, replacement and maintenance have a ledger. Under the condition of conditions, the maintained equipment should be tested offline before going online to ensure that the spare parts can be used normally. Only constant efforts, to ensure the normal operation of online equipment, to ensure the smooth production.
Case study:
The normal condition of the DC motor commutator is golden yellow, and the surface forms an oxide film. After the wear of the carbon brush, the powder sticks to the commutator and the groove of the commutator, making the commutator become black, and serious will cause the motor to spark or even burn the commutator.
In this case, compressed air can not blow down the toner, need to use a clean white cloth, dipped in cleaning agent or alcohol to wipe down the toner stuck on the commutator, and then use the hook made of hacksaw blade to hook out the toner in the commutator groove. After finishing, the oxide film on the surface of the commutator may be damaged, and the load should be gradually increased after running under low load for a period of time.