How to do the daily maintenance of energy-saving inverters?

2021-10-30 13:39:59 jact_elec

How to do the daily maintenance of energy-saving inverters?High-efficiency and energy-saving inverters have made great contributions to the energy-saving, miniaturization, and automation of production machinery over the years, and are increasingly used in various fields. If you want to maintain the working state of the high-efficiency inverter, its maintenance also has corresponding methods and precautions to ensure that the inverter is used for trouble-free and high-efficiency operation.

Daily maintenance and overhaul of energy-saving inverters are necessary

High-efficiency energy-saving inverters also require routine maintenance and regular maintenance like other electronic equipment. Whether the frequency converter runs well and reliably, and the long and short service life is closely related to its daily maintenance and regular maintenance.

Energy-saving inverter is a static device composed mainly of semiconductors. Due to the influence of temperature, humidity, dust, etc., and the aging of its parts over the years, in order to ensure the efficiency and normal operation of the inverter, it must be The frequency converter carries out routine maintenance and regular maintenance.

Matters needing attention in daily maintenance of high-efficiency and energy-saving inverters

  • Ensure safety

Personal safety and equipment safety must be ensured. First of all, the operator must be familiar with the basic principles, functional characteristics, indicators, etc. of the inverter, and have experience in the operation of the inverter, and irrelevant personnel must not operate the inverter at will. Secondly, pay attention to the danger of high voltage, and also pay attention to the operation after the capacitor in the power module is fully discharged. High-voltage inverters are high-voltage products, and there are dangerous voltages of 3kV, 6kV, and 10kV in the cabinet. Before the equipment is installed and put into operation, the user must carefully read and understand the "User Manual" and strictly abide by the operating procedures.

  • Before doing any maintenance and repair work, strictly follow the operating procedures.

  • Do not touch any part of the cabinet before confirming that there are no heating elements and no electricity.

  • During maintenance, be sure to cut off the high voltage and check that the red indicator lights of all units are completely extinguished before replacement or measurement.

  • Do not connect the high-voltage power supply to the output terminal of the inverter by mistake, otherwise the internal components of the inverter may explode.

  • Do not use a high-voltage shaker to measure the output insulation of the inverter, which may damage the switching devices in the power unit.

  • When the transformer is under voltage test, it is necessary to disconnect all power units from the inverter, and disconnect the temperature controller from the temperature probe

  • Never disconnect the control power supply during medium voltage power supply. This will cause serious unit damage.

Daily inspection

  • Check whether the following abnormal phenomena occur during operation

Does the motor run as expected;

Whether the installation environment is abnormal;

Whether the cooling system is abnormal;

Whether there is abnormal vibration, abnormal sound;

Whether there is abnormal overheating, discoloration;

Pay attention to observe the input and output voltage and current of the inverter during operation. You can measure the output of PT during operation to correct the input and output voltage displayed on the interface, and complete the current correction through the oscilloscope.

  • Daily inspection items

Ambient temperature: Whether the ambient temperature of the high-voltage chamber is abnormal. Because the ambient temperature of the inverter installation site has a large temperature difference between winter and summer, you should always pay attention to the indoor temperature and keep it between 0 and 40 degrees.

Transformer temperature: On-duty personnel or maintenance personnel should regularly inspect and inspect the transformer, record the temperature of the transformer windings, and check whether the three-phase temperature is balanced

Whether the cooling system is normal: mainly observe whether the cooling fan rotates normally, whether the steering is correct, there should be no alarm prompt on the interface; whether the cooling device of the environment is working normally, including air conditioners, air ducts, water and air coolers, etc.

Temperature controller: Check whether the set temperature of the temperature controller is appropriate and whether it works normally.

Indicator light: Check whether the indicator light on the cabinet door of the inverter indicates normal.

UPS: Generally, inverters are equipped with UPS. In daily inspections, attention should be paid to check the working status of the UPS and confirm that the UPS is working in the normal channel.

Equipment appearance inspection

Check whether the energy-saving inverters, motors, transformers, fans, etc. are overheated, discolored or have peculiar smells.

Regular inspection and comparison of components in the cabinet, such as electromagnetic locks, etc.

Check the running sound: check the frequency converter, motor, and fan for abnormal vibration and sound. The noise level of the inverter should be ≤75dB under normal conditions

Is the voltage input normal

Check whether the main circuit voltage and control power supply voltage are normal. The input power of the normal inverter allows a certain fluctuation range, within which the inverter can maintain full load output without being affected. After exceeding a certain range, the inverter can derate and continue to run.

Are various displays normal

Check whether the voltage, current, and temperature on the inverter panel are normal, and whether there is an alarm signal, etc.

Regular maintenance

Cleaning and replacing the filter

Clean the dust on the dust-proof filter of the cabinet door every half a month to ensure the unobstructed cooling air path. If the environmental dust pollution is serious, the time for regular cleaning should be shortened.

Generally, the equipment comes with a set of spare filters, which can be blown with compressed air or washed with water.

Wipe the floor frequently daily to keep the floor clean and prevent the inverter from being polluted by dust on the floor.

Consider replacing it after long-term use.

Fastening of fixing bolts

In three months or so, check all bolts once to see if they are loose or discolored. If they are loose, they should be tightened again. If they are discolored, they need to be replaced.

  • Dust removal

Clean the inside of the industrial computer for about half a year. If the dust is not cleaned for a long time, failures such as insulation breakdown and creepage are likely to occur in humid weather; check whether the board is loose and prevent poor contact; check whether the CPU fan can be flexible If the CPU fan fails, it will cause the control board and other boards to overheat and fail.

In the event of a power outage, perform a comprehensive dust-removal treatment for the inverter in about half a year.

If it cannot be performed regularly, the dust-removal treatment can be arranged every time the equipment is shut down. At the same time, high-voltage equipment such as high-voltage porcelain bottles, insulators, voltage transformers, and arresters are also required Clean the dust regularly.

  • Ventilation and heat dissipation

When the ambient temperature is high in summer, the ventilation of the inverter installation site should be strengthened to ensure good ventilation and heat dissipation conditions for the inverter. If the inverter resumes operation after stopping, if the environment is humid, the inverter should be ventilated for half an hour to get rid of the internal moisture of the inverter, and then put into operation with high voltage power.

  • Activation of electrolytic capacitor

If the inverter is shut down for a long time, high-voltage power should be applied once every six months for at least one hour to prevent the electrolytic capacitor from deteriorating due to increased leakage and reduced withstand voltage. The electrolytic capacitors in the spare modules in the inventory should also be activated once every six months.

  • UPS battery activation

When the inverter is working normally, the battery in the UPS is in a floating state for a long time, and the battery needs to be charged and discharged every three months or so to activate it. At the same time, the performance of the battery can also be tested, and the problem can be found in time to replace the battery.

Other items to be checked

Whether the conductor insulation is corroded or overheated, discolored or damaged.

Check whether the insulation resistance is within the normal range.

Check and replace the cooling fan.

Check whether the terminal block is damaged and whether the contact is rough.

After the transformer is put into operation, it should be cleaned every year, and insulation resistance measurement and withstand voltage test should be carried out.

Check the lap of the cable. For example, if the cable laps on the connecting bolt, the heating of the bolt causes the insulation of the overlapped cable to be overheated and damaged.