Inverter installation and precautions - Solutions - Huaqiang Electronic Network

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1. Installation environment
(1) Ambient temperature Inverter, like other electronic devices, has certain requirements for ambient temperature, generally “-10～+40°C”. Since the inverter is a high-power electronic device, it is highly susceptible to the operating temperature. However, in order to ensure the safety and reliability of the inverter, it should be considered to leave room for use, preferably below 40 °C; 40~ For derating between 50 °C, the rated output current must be reduced by 1% for every 1 °C increase. If the ambient temperature is too high and the temperature changes greatly, the insulation of the inverter will be greatly reduced, affecting the life of the inverter.
(2) Ambient humidity The inverter has the same requirements for ambient humidity as other electrical equipment. The relative humidity of the surrounding air of the inverter is ≤95% (no condensation). It must be placed in the inverter cabinet according to the working environment of the site. Agent and heater.
(3) Vibration and shock During the operation of the inverter, care should be taken to avoid vibration and shock. As we all know, the inverter is assembled from many components by soldering, screwing, etc. When the inverter or the control cabinet of the inverter is subjected to mechanical vibration or impact, the connection device or the connector such as the solder joint or the screw may be loose or fall off, causing serious electrical contact failure or even a short circuit such as a short circuit during the period. Therefore, in addition to improving the mechanical strength of the control cabinet, away from the vibration source and the impact source, the inverter should also be equipped with an anti-vibration rubber gasket outside the control cabinet, and a buffer rubber between the device and the mounting plate in the control cabinet. Pad, shock absorption.
Generally, after the equipment is running for a period of time, the control cabinet should be inspected and maintained.
(4) Electrical environment ● Prevent electromagnetic interference The electrical main body of the inverter is the hardware and software circuit of the power module and its control system. When these components and software programs are subjected to certain electromagnetic interference, hardware circuit failure, software program flight, etc. may occur. Caused an operational accident. Therefore, in order to avoid electromagnetic interference, the inverter should have measures to prevent electromagnetic interference according to the electrical environment. For example, the input power line, output motor line, and control line should be far away; the easily affected equipment and signal lines should be installed away from the inverter as much as possible; the key signal lines should use shielded cables. It is recommended that the shield be grounded by 360° grounding method. .
● Prevent the overvoltage of the input terminal The main circuit of the inverter is composed of power electronic devices. These devices are very sensitive to overvoltage. Overvoltage at the input end of the inverter will cause permanent damage to the main components. For example, some factories have their own generators, and the grid fluctuations will be relatively large. Therefore, there should be preventive measures for the overvoltage of the input terminals of the inverter.
(5) Altitude The inverter can be installed at rated altitude below 1000m above sea level. However, if the altitude exceeds 1000m, the output power will decrease. For example, the altitude and output current of the installation location of the inverter are shown in Figure 1. It can be seen that the altitude exceeds 1000m, and the output current of the inverter is reduced. When the altitude is 4000m, the output current is 40% at 1000m.

Figure 1 Comparison of altitude and output current of the installation location of the inverter

(6) Other environment ● Avoid installing the inverter in places where rain drops or condensation;
● Prevent dust, cotton wool and metal fines from entering;
● Avoid installing the inverter in places with a lot of oil and salt;
● Keep away from radioactive materials and combustibles.
2. Installation method and heat treatment The inverter has power loss during operation and is converted into heat energy to raise its own temperature. Roughly speaking, the power loss per 1kva of the inverter capacity is about 40w ~ 50w. Therefore, when installing the inverter, consider the heat dissipation problem of the inverter. Consider how to fully dissipate the heat generated when the inverter is running. Therefore, pay attention to the installation method.
(1) The outer casing of the wall-mounted inverter is designed to be relatively firm. Under normal circumstances, it is allowed to be directly mounted on the wall, which is called wall-mounted. In order to ensure good ventilation, all inverters must be installed vertically. The distance between the inverter and surrounding objects should meet the following conditions, as shown in Figure 2: both sides are larger than 100mm, the upper and lower is greater than 150mm, and in order to prevent debris from falling into the frequency conversion The air outlet of the device blocks the air duct, and the baffle is preferably installed above the air outlet of the inverter.

Figure 2 Wall-mounted inverter installation diagram

(2) Cabinet installation method When there is too much dust on the site, the humidity is relatively large, or there are many peripheral accessories of the inverter, when it needs to be installed together with the inverter, it can be installed in cabinet. Inverter cabinet installation is currently the best installation method, because it can play a good shield radiation interference, but also can prevent dust, moisture, and light. Precautions for cabinet installation:
●When a single inverter adopts the cooling method inside the cabinet, the exhaust fan should be installed at the top of the inverter cabinet, and it should be installed directly above the inverter (this is convenient for air circulation);
● Installation of multiple inverters should be installed side by side as much as possible. If it must be installed in a longitudinal manner, a partition should be installed between the two inverters.