【Daily Question 20090219】What are the requirements for the installation environment of frequency converters?

Variable frequency drives are electronic devices, and their specification sheets detail the requirements for the installation and operating environment. Vibration is the main cause of mechanical damage to electronic devices; in environments with severe vibration impacts, vibration-damping measures such as rubber should be used ； Humid, corrosive gases, and dust can cause electronic devices to rust, result in poor contacts, and lead to reduced insulation which in turn causes short circuits ； Temperature is an important factor affecting the lifespan and reliability of electronic devices, especially semiconductor devices; air conditioning should be installed or direct sunlight should be avoided according to the environmental conditions required by the device. It is very necessary to regularly check the air filter and cooling fan of the frequency converter. Currently, the cooling fans of the frequency converters in use at the oil production plants are in poor condition; moreover, some of these frequency converters operate in harsh environments, which severely affects heat dissipation and air circulation. As a result, these frequency converters tend to trip or trigger overheat alarms during hot seasons.

Installation environment for the inverter: temperature from -10 ℃ to 30 ℃, altitude of 2000 m. If the ambient temperature increases by 5°C above the normal maximum ambient temperature, its operating power should decrease by approximately 10%.

The ambient temperature is generally “-10～+40”℃”； Use at a reduced capacity between 40–50°C; for every 1°C increase in temperature, the rated output current must be reduced by 1%. When the ambient temperature is too high and there are large temperature fluctuations, the insulation of the inverter **degrades, which affects its lifespan. Environmental humidity: The relative humidity of the air surrounding the frequency converter should be ≤95% (with no condensation). If necessary, desiccants and heaters should be installed inside the frequency converter cabinet depending on the working conditions on site. Vibration and shock: Be careful to avoid exposure to vibration and shock. Electrical environment: To prevent electromagnetic interference, the input power cable, output motor cable, and control cables should be kept at a proper distance from each other ； Equipment and signal lines that are susceptible to interference should be kept as far away as possible from the inverter installation site ； Critical signal cables should be shielded cables. Avoid installing the inverter in areas where rainwater drips or condensation occurs; prevent dust, cotton fluff, and metal shavings from entering; keep it away from radioactive materials and flammable substances.

Requirements of the installation environment for frequency converters. 　　(1) Ambient temperature: It is generally suitable for operation in environments with temperatures ranging from -10°C to 40°C, and with a humidity level of no more than 90%. When the ambient temperature is above 40°C, for every 1°C increase, the inverter should be used at a reduced capacity of 5%. 　　(2) General requirements at the installation site: 1) No corrosion, no flammable or explosive gases or liquids. 2) No dust, floating fibers, or metal particles. 3) The foundation and walls of the installation site must be solid, undamaged, and free from vibrations. 4) Direct sunlight should be avoided. 5) There should be no electromagnetic interference. (3) Installation space and ventilation for the inverter: The inverter is equipped with cooling fans for forced air cooling; to ensure an effective cooling cycle, it must be installed vertically. When installing multiple frequency converters in the same device or control box, to reduce mutual thermal influence, it is recommended to install them side by side. 　　(4) Removal of the inverter cover: During installation, it is necessary to test, inspect, and connect wires to the inverter, which requires removing its cover. It is important to pay attention to the characteristics of different frequency converters and install them according to those characteristics. 　　(5) Inverter wiring: 1) Whether there are any wiring errors. 2) Whether there is wire debris inside the inverter, especially metal shavings, broken ends, as well as screws and nuts. 3) Whether the screws are tightened properly and whether the wires are loose. 4) Whether the exposed parts of the terminal connections come into contact with other live parts of the terminals, or touch the inverter’s casing. 　　(6) Precautions for wiring the control circuit: 1) The wiring of the control circuit and the main circuit, as well as that of other power lines, should be separated and kept at a certain distance from each other. 2) The wire leads for the relay contact terminals in the inverter control circuit should be routed separately from the wires connecting to the terminals of other control circuits, in order to avoid interference signals that may occur when the contacts close or open. 3) To prevent interference caused by signals such as noise from leading to incorrect operation of the inverter, shielded cables are used in the control circuit. 　　(7) Special installation for variable frequency drives.

Installation environment for the inverter: temperature from -10 ℃ to 40 ℃, altitude of 1000m. If the ambient temperature increases by 5°C above the normal maximum ambient temperature, its operating power should decrease by approximately 30%.

Problems encountered in the use of frequency converters and fault prevention: Incorrect usage methods or inappropriate installation conditions can easily lead to improper operation of the frequency converter, faults, or failure to achieve the desired performance. To prevent problems before they occur, it is particularly important to conduct a thorough analysis of the causes of failures in advance. External electromagnetic interference: If there are sources of interference around the inverter, they can penetrate into the inverter through radiation or power lines, causing errors in the control circuit and leading to abnormal operation or shutdown; in severe cases, it may even damage the inverter. While it is important to improve the anti-interference capability of the inverter itself, due to cost constraints associated with the device, it is more reasonable and necessary to take noise suppression measures externally to eliminate the sources of interference. The following measures are specific ways to implement the \"three no’s\" principle for dealing with noise interference: Absorbers to prevent surge voltages, such as RC absorbers, must be installed on the control coils of all relays and contactors surrounding the frequency converter ； Try to shorten the wiring distance of the control circuit and separate it from the main circuit ； Designating the use of shielded wire circuits must be carried out in accordance with regulations; if the distance between the lines is large, a suitable relay method should be employed ； The grounding terminal of the frequency converter shall be installed in accordance with regulations, and it must not be used together with welding or power grounding connections ； A noise filter is installed at the input of the inverter to prevent interference caused by the power supply lines. Installation environment: Frequency converters are electronic devices, and their specifications detail the requirements for the installation and operating environment. In special cases, where it is truly impossible to meet these requirements, appropriate suppression measures must be employed as much as possible: vibration is the main cause of mechanical damage to electronic devices; in situations with significant vibration impacts, vibration-damping measures such as rubber should be used ； Humid, corrosive gases, and dust can cause electronic devices to rust, lead to poor connections, and reduce insulation resulting in short circuits. As preventive measures, the control boards should be treated to resist corrosion and dust, and a sealed design should be employed ； Temperature is an important factor affecting the lifespan and reliability of electronic devices, especially semiconductor devices; air conditioning should be installed or direct sunlight should be avoided according to the environmental conditions required by the device. In addition to the above three points, it is also very necessary to regularly check the air filter and cooling fan of the inverter. For special high-cold environments, to prevent microprocessors from failing to function properly due to low temperatures, necessary measures such as installing space heaters should be taken. Power supply abnormalities can manifest in various forms, but they can be roughly divided into the following 3 types: phase loss, low voltage, and power outages; sometimes mixed forms of these conditions also occur. The main causes of these abnormal phenomena are mostly damage to the transmission lines caused by wind, snow, and lightning strikes; sometimes they are also due to ground faults and inter-phase short circuits within the same power supply system. Thunderstorms vary greatly depending on region and season. In addition to voltage fluctuations, some power grids or self-generated power units also experience frequency fluctuations, and these phenomena sometimes occur repeatedly in short periods of time. To ensure the proper operation of equipment, corresponding requirements are also placed on the power supply for inverters. If there are devices such as direct-start motors and induction cookers in the vicinity, to prevent voltage drops that occur when these devices are turned on, they should be separated from the inverter power supply system in order to reduce mutual interference ； For applications that require continued operation after an instantaneous power outage, in addition to selecting an inverter at an appropriate price, it is also necessary to consider in advance the speed reduction ratio of the load motor. The inverter and the external control circuit employ a transient loss compensation method; once the voltage is restored, speed tracking together with the readings from the tachometer are used to prevent overcurrent during acceleration ； For equipment that must operate continuously, an automatic switching uninterruptible power supply device should be installed on the frequency converter. Inverters with diode inputs and single-phase control power supplies can continue to operate even in the event of a missing phase, but excessive current in certain components of the rectifier as well as high pulse currents in the capacitors can have an adverse effect on the lifespan and reliability of the inverter if such conditions persist over time; therefore, it is necessary to conduct inspections and take corrective actions as soon as possible.

Installation environment of the inverter； I. Operating temperature. The interior of an inverter contains high-power electronic components that are highly sensitive to operating temperature. The recommended operating range is generally 0–55°C, but to ensure safe and reliable operation, it is advisable to keep the temperature below 40°C. In the control cabinet, the frequency converter should generally be installed at the upper part of the cabinet, and the installation requirements specified in the product manual must be strictly followed; it is absolutely not allowed to install heat-generating components or components that tend to generate heat close to the bottom of the frequency converter. II. Ambient temperature. When the temperature is too high and fluctuates significantly, condensation can occur inside the inverter, which reduces its insulation properties and may even lead to short-circuit accidents. If necessary, desiccants and heaters must be added to the box. In water treatment rooms, the humidity is usually high, and this issue becomes more pronounced if there are large temperature fluctuations. III. Corrosive gases. In an environment with high concentrations of corrosive gases, not only will the leads of components and printed circuit boards be corroded, but the aging of plastic components will also be accelerated, reducing their insulation properties. IV. Vibration and shock. When a control cabinet equipped with an inverter is subjected to mechanical vibration and shock, it can lead to poor electrical contacts. This is the problem that has arisen at Huai’an Thermal Power. At this time, in addition to improving the mechanical strength of the control cabinet and keeping it away from vibration and impact sources, seismic rubber pads should also be used to secure components that generate vibration, such as the electromagnetic switches inside and outside the control cabinet. After the equipment has been in operation for a period of time, it should be inspected and maintained. V. Electromagnetic interference. During operation, the inverter generates a large number of interference electromagnetic waves due to rectification and frequency conversion; these high-frequency electromagnetic waves can interfere with nearby meters and instruments. Therefore, the instruments and electronic systems inside the cabinet should be equipped with metal enclosures to shield them from the interference caused by the frequency converter. All components must be reliably grounded. In addition, the connections between various electrical components, instruments, and meters should use shielded control cables, with the shielding layer also being grounded. If electromagnetic interference is not properly managed, it can often render the entire system inoperable, causing the control unit to fail or get damaged.

This answer repeats what some of the previous friends said, but I still insist on it: The installation environment for the inverter should be at a temperature range of -10 ℃ to 30 ℃, at an altitude of 2000 meters. If the ambient temperature increases by 5°C above the normal maximum ambient temperature, its operating power should decrease by approximately 10%.

Installation environment for the inverter: temperature from -10°C to 40°C, altitude of 1000 m. If the ambient temperature increases by 5°C above the normal maximum ambient temperature, its operating power should decrease by approximately 30%.

The ambient temperature is generally “-10～+40”℃”； Use at a reduced capacity between 40–50°C; for every 1°C increase in temperature, the rated output current must be reduced by 1%. When the ambient temperature is too high and there are large temperature fluctuations, the insulation of the inverter **degrades, which affects its lifespan. Environmental humidity: The relative humidity of the air surrounding the frequency converter should be ≤95% (with no condensation). If necessary, desiccants and heaters should be installed inside the frequency converter cabinet depending on the working conditions on site. Vibration and shock: Be careful to avoid exposure to vibration and shock. Electrical environment: To prevent electromagnetic interference, the input power cable, output motor cable, and control cables should be kept at a proper distance from each other ； Equipment and signal lines that are susceptible to interference should be kept as far away as possible from the inverter installation site ； Critical signal cables should be shielded cables. Avoid installing the inverter in areas where rainwater drips or condensation occurs; prevent dust, cotton fluff, and metal shavings from entering; keep it away from radioactive materials and flammable substances.

The installation requirements are as follows: (1) Ensure that all devices in the control cabinet are properly grounded; short, thick grounding wires should be used (flat conductors or metal mesh are preferred, as they have lower impedance at high frequencies) to connect to the common ground. According to **standard regulations, its grounding resistance should be less than 4 ohms. Additionally, the control devices connected to the inverter (such as PLCs or PID controllers) must be grounded together with it. (2) When installing the wiring, separate the power cable from the control cable, for example by using separate conduit trays. If the control circuit wires must cross the power cable, they should be routed to intersect at 90°. (3) When using shielded wires or twisted pairs to connect the control circuit, ensure that the unshielded sections are as short as possible; cable sleeves should be used when conditions permit. (4) Ensure that the contactors in the control cabinet have arc-quenching functionality; AC contactors should be equipped with R-C suppressors, or varistor suppressors can also be used. This is particularly important if the contactors are controlled by the relay of an inverter. (5) When using shielded and armored cables for motor wiring, the shield layer must be grounded at both ends. (6) If the inverter is operating in a noise-sensitive environment, an RFI filter can be used to reduce the conductive and radiative interference emitted by the inverter. To achieve optimal results, there should be good electrical conductivity between the filter and the mounting metal plate.

The specific installation environment is as mentioned by the above, and for the particular brands, their manuals should be referred to. From a practical operation perspective, the following points are particularly important: 1. The temperature of the surrounding environment; excessively high temperatures can prevent the inverter from functioning properly. This factor needs to be taken into consideration when installing multiple units together, especially in areas such as fermentation workshops with high temperatures. 2. The impact of humidity: In normal environments, there is no problem, but when high humidity exists in a particular area, special precautions must be taken. In one company, the frequency converters stopped working due to inadequate sealing; steam was used for heating outdoor mixing tanks, and this led to an influx of steam into the electrical control room, causing multiple frequency converters to shut down as a result of protective measures being activated. 3. Dust prevention, which affects fans.

Requirements for the installation environment of the frequency converter: (1) Operating temperature. The interior of an inverter contains high-power electronic components that are highly sensitive to operating temperature. The recommended operating range is generally 0–55°C, but to ensure safe and reliable operation, it is advisable to keep the temperature below 40°C. In the control cabinet, the frequency converter should generally be installed at the upper part of the cabinet, and the installation requirements specified in the product manual must be strictly followed; it is absolutely not allowed to install heat-generating components or components that tend to generate heat close to the bottom of the frequency converter. (2) Ambient temperature. When the temperature is too high and fluctuates significantly, condensation can occur inside the inverter, which reduces its insulation properties and may even lead to short-circuit accidents. If necessary, desiccants and heaters must be added to the box. In water treatment rooms, the humidity is usually high, and this issue becomes more pronounced if there are large temperature fluctuations. (3) Corrosive gases. In an environment with high concentrations of corrosive gases, not only will the leads of components and printed circuit boards be corroded, but the aging of plastic components will also be accelerated, reducing their insulation properties. (4) Vibration and shock. When a control cabinet equipped with an inverter is subjected to mechanical vibration and shock, it can lead to poor electrical contacts. This is the problem that has arisen at Huai’an Thermal Power. At this time, in addition to improving the mechanical strength of the control cabinet and keeping it away from vibration and impact sources, seismic rubber pads should also be used to secure components that generate vibration, such as the electromagnetic switches inside and outside the control cabinet. After the equipment has been in operation for a period of time, it should be inspected and maintained. (5) Electromagnetic wave interference. During operation, the inverter generates a large number of interference electromagnetic waves due to rectification and frequency conversion; these high-frequency electromagnetic waves can interfere with nearby meters and instruments. Therefore, the instruments and electronic systems inside the cabinet should be equipped with metal enclosures to shield them from the interference caused by the frequency converter. All components must be reliably grounded. In addition, the connections between various electrical components, instruments, and meters should use shielded control cables, with the shielding layer also being grounded. If electromagnetic interference is not properly managed, it can often render the entire system inoperable, causing the control unit to fail or get damaged.

Variable frequency drives are electronic devices, and their specification sheets detail the requirements for the installation and operating environment. In special cases, where it is truly impossible to meet these requirements, appropriate suppression measures must be employed as much as possible: vibration is the main cause of mechanical damage to electronic devices; in situations with significant vibration impacts, vibration-damping measures such as rubber should be used ； Humid, corrosive gases, and dust can cause electronic devices to rust, lead to poor connections, and reduce insulation resulting in short circuits. As preventive measures, the control boards should be treated to resist corrosion and dust, and a sealed design should be employed ； Temperature is an important factor affecting the lifespan and reliability of electronic devices, especially semiconductor devices; air conditioning should be installed or direct sunlight should be avoided according to the environmental conditions required by the device. In addition to the above three points, it is also very necessary to regularly check the air filter and cooling fan of the inverter. For special high-cold environments, to prevent microprocessors from failing to function properly due to low temperatures, necessary measures such as installing space heaters should be taken.

Requirements of the installation environment for frequency converters. 　　(1) Ambient temperature: It is generally suitable for operation in environments with temperatures ranging from -10°C to 40°C, and with a humidity level of no more than 90%. When the ambient temperature is above 40°C, for every 1°C increase, the inverter should be used at a reduced capacity of 5%. 　　(2) General requirements for the installation site: 1) No corrosion, no flammable or explosive gases or liquids. 2) No dust, floating fibers, or metal particles. 3) The foundation and walls of the installation site must be solid, undamaged, and free from vibrations. 4) Direct sunlight should be avoided. 5) There should be no electromagnetic interference. (3) Installation space and ventilation for the inverter: The inverter is equipped with cooling fans for forced air cooling; to ensure an effective cooling cycle, it must be installed vertically. When installing multiple frequency converters in the same device or control box, to reduce mutual thermal influence, it is recommended to install them side by side. 　　(4) Removal of the inverter cover: During installation, it is necessary to test, inspect, and connect wires to the inverter, which requires removing its cover. It is important to pay attention to the characteristics of different frequency converters and install them according to those characteristics. 　　(5) Inverter wiring: 1) Whether there are any wiring errors. 2) Whether there is wire debris inside the inverter, especially metal shavings, broken ends, as well as screws and nuts. 3) Whether the screws are tightened properly and whether the wires are loose. 4) Whether the exposed parts of the terminal connections come into contact with other live parts of the terminals, or touch the inverter’s casing. 　　(6) Precautions for wiring the control circuit: 1) The wiring of the control circuit and the main circuit, as well as that of other power lines, should be separated and kept at a certain distance from each other. 2) The wire leads for the relay contact terminals in the inverter control circuit should be routed separately from the wires connecting to the terminals of other control circuits, in order to avoid interference signals that may occur when the contacts close or open. 3) To prevent interference caused by signals such as noise from leading to incorrect operation of the inverter, shielded cables are used in the control circuit. 　　(7) Corrosive gases. In an environment with high concentrations of corrosive gases, not only will the leads of components and printed circuit boards be corroded, but the aging of plastic components will also be accelerated, reducing their insulation properties. (8) Vibration and shock. When a control cabinet equipped with an inverter is subjected to mechanical vibration and shock, it can lead to poor electrical contacts. This is the problem that has arisen at Huai’an Thermal Power. At this time, in addition to improving the mechanical strength of the control cabinet and keeping it away from vibration and impact sources, seismic rubber pads should also be used to secure components that generate vibration, such as the electromagnetic switches inside and outside the control cabinet. After the equipment has been in operation for a period of time, it should be inspected and maintained. (9) Electromagnetic wave interference. During operation, the inverter generates a large number of interference electromagnetic waves due to rectification and frequency conversion; these high-frequency electromagnetic waves can interfere with nearby meters and instruments. Therefore, the instruments and electronic systems inside the cabinet should be equipped with metal enclosures to shield them from the interference caused by the frequency converter. All components must be reliably grounded. In addition, the connections between various electrical components, instruments, and meters should use shielded control cables, with the shielding layer also being grounded. If electromagnetic interference is not properly managed, it can often render the entire system inoperable, causing the control unit to fail or get damaged.

The frequency converter must be suitable for its installation environment, which requires taking into account factors such as ambient temperature, humidity, dust, pH level, and corrosive gases. These factors are crucial for ensuring that the frequency converter can operate safely and reliably over the long term. Ambient temperature: It is generally suitable for operation in ranges of -10°C to 40°C, with humidity levels below 90%. When the ambient temperature is above 40°C, for every 1°C increase, the inverter should be used at a reduced capacity of 5%.

Both the environment and temperature can be easily defined. However, another threat to the proper operation of frequency converters is dust. Since the high-power components and circuit boards inside frequency converters are electronic devices, the accumulation of dust can lead to short circuits in certain areas and affect heat dissipation. Therefore, it is essential to take dust-proof measures in the environment where high-power frequency converters are used, including protecting the cable connections from dust; this will help to extend the equipment’s lifespan.

1. Ambient temperature: –10°C to 40°C 2. Ambient humidity: Relative humidity not exceeding 90% (no condensation) 3. Other conditions: No direct sunlight, no corrosive or flammable gases, low dust levels, altitude below 1000m

(1) Ambient temperature and humidity. The inverter contains high-power electronic components that are highly susceptible to the effects of the surrounding environment. Therefore, the installation location must maintain a temperature between -10 and 40°C, with a relative humidity of less than 90%, and no condensation allowed. If installed inside a distribution panel, necessary measures must be taken (such as using electric fans) to ensure that the operating temperature does not exceed 40°C. If the ambient temperature is too high and there are large temperature fluctuations, condensation can occur inside the inverter, which will **reduce its insulation properties and may even lead to short-circuit failures. If necessary, desiccant must be added to the box. 　　(2) Air quality. Inverters must not be installed in areas with corrosive gases, conductive dust, and particles. In an environment with high concentrations of corrosive gases, these gases not only corrode the leads of components and printed circuit boards, but also accelerate the aging of plastic components and reduce their insulation properties. In such cases, the control box should be designed as a sealed structure with proper ventilation. 　　(3) Elevation and vibration. The inverter should be installed at an altitude of less than 1,000 meters, with ambient vibrations below 0.5G. When a control cabinet equipped with an inverter is subjected to mechanical vibration and shock, it can lead to poor electrical contacts. At this time, in addition to improving the mechanical strength of the control cabinet and keeping it away from vibration and impact sources, seismic rubber pads should also be used to secure components that generate vibration, such as the electromagnetic switches inside and outside the control cabinet. The installation location of the inverter should also be kept away from direct sunlight, and measures should be taken to prevent iron shavings, water droplets, and other substances from entering the inverter. In the control box, the frequency converter should generally be installed at the upper part of the box, and the installation requirements specified in the product manual must be strictly followed: it must be installed vertically, with sufficient space for heat dissipation around it in all directions. It is absolutely not allowed to install heating elements or components that are prone to heating close to the bottom of the inverter. Furthermore, to prevent foreign objects from falling into or getting stuck in the exhaust outlet of the inverter and blocking the air duct, it is advisable to install a protective mesh cover above the exhaust outlet of the inverter.

The installation environment for frequency converters mainly includes the following aspects: 1. Ambient temperature: Like other electronic devices, frequency converters have certain requirements regarding the surrounding temperature, which is generally “-10～+40℃”. When the ambient temperature is too high and there are large temperature fluctuations, the insulation of the inverter **degrades, which affects its lifespan. 2. Environmental humidity: Like other electrical equipment, inverters also have certain requirements regarding environmental humidity; the relative humidity of the air surrounding the inverter should be ≤95%. 3. Vibration and shock: During operation, it is important to prevent inverters from being subjected to vibration and shock. 4. Electrical environment: a. Prevent electromagnetic interference ； b. Prevent overvoltage at the input terminal