Due to the inherent design of frequency converters , their normal operation is significantly affected by external environmental conditions. To ensure these conditions remain within a certain range, regular environmental maintenance and preventative checks are performed on the frequency converters to optimize their operating environment. This allows for early detection and resolution of hidden faults, reducing the likelihood of serious failures and minimizing equipment downtime. Based on our company's extensive field experience, we have summarized the following:
1. Ambient temperature: When the temperature is too high and the temperature fluctuates greatly, condensation is likely to occur inside the frequency converter. Especially when the equipment is powered on again after being shut down, the frequency converter cools down after being shut down, and the moisture in the air cools and adheres to the circuit board, the casing, and the copper plates. Its insulation performance will be greatly reduced, and it may even cause a short circuit. If a lot of dust accumulates inside the frequency converter at this time and is not maintained and cleaned in time, the failure rate of the frequency converter will be very high, and there is even a possibility that multiple pieces of equipment will be damaged at the same time, directly leading to production stoppage.
2. Inverter operating temperature: The inverter contains high-power electronic components that are highly susceptible to the influence of operating temperature. Too high or too low a temperature will cause the electronic components to malfunction. To ensure the normal operation of the inverter, it is necessary to ensure that the inverter cabinet has a good ventilation and heat dissipation system, that the air inlet and outlet of the cabinet are not blocked, and that the ventilation fan is working properly.
3. Vibration and shock: Since the internal electrical connections of the frequency converter are usually screw connections and the ribbon cables between the circuit boards are also connectors, if the frequency converter vibrates a lot during operation, it is easy to cause poor contact in these parts.
4. Dust: Inverters are not suitable for operation in dusty conditions. Since inverters rely on forced air cooling for heat dissipation, excessive dust can easily cause the inverter's cooling fan to block or even burn out. Dust can also block the cooling air duct, preventing heat from being dissipated in time. As a result, the inverter will not receive proper heat dissipation, and its operating temperature will rise, leading to an overheating alarm and shutdown. In severe cases, it can directly damage the inverter.
5. Power Supply: Power supply abnormalities can be broadly categorized into three types: phase loss, low voltage, and overvoltage. These three conditions will directly cause the frequency converter to malfunction. The main causes of these abnormalities are mostly due to transmission lines. Sometimes, they are also caused by short circuits to ground or between phases within the same power supply system, or by the start-up or shutdown of large power equipment. In addition to voltage fluctuations, some power grids or self-generated units may also experience frequency fluctuations. Furthermore, these phenomena sometimes recur within a short period of time. To ensure the normal operation of the equipment, corresponding requirements are also placed on the power supply of the frequency converter.
6. Lightning strikes and induced lightning: Lightning strikes or induced lightning can generate surge voltages. During seasons with more frequent lightning, lightning strikes entering the power grid can damage the frequency converter. Therefore, it is necessary to inspect the lightning protection devices to ensure their proper functioning. Furthermore, when the primary side of the power system has a vacuum circuit breaker, short-circuit switching can generate high surge voltages. To prevent overvoltage damage caused by surge voltages, it is usually necessary to add absorption devices such as varistors at the input of the frequency converter. Vacuum circuit breakers should be equipped with RC surge absorbers. If there is a vacuum circuit breaker on the primary side of the transformer, the control timing should ensure that the frequency converter is disconnected before the vacuum circuit breaker operates. Electricians operating the equipment must meet these operational requirements.
