A variable frequency drive (VFD) is essential for controlling the operation of an electric motor. It allows you to control the speed of your motor by varying its frequency and power supply voltage.
Controlling the speed of your motor with a VFD allows you to save energy and improve system efficiency, match the speed of the drive to the process requirements, match the torque or power of the drive to the process requirements, and reduce mechanical stress on the motor-driven appliances.
Along with all of these applications, it is critical to ensure that your variable frequency drive runs smoothly. If there are any problems with its operation, it is best to seek the assistance of a reputable AC VFD drive repair service to help you resolve the issue. Numerous causes of VFD failure must be addressed immediately before they exacerbate into larger problems. If you are experiencing over-voltage faults, erratic operation, or strange noises from your VFD, this is an indication that your device is experiencing a problem.
Before contacting a professional AC VFD drive repair service or electronic repair, you can attempt to troubleshoot the VFD fault you are experiencing by determining the cause of its failure.
Here are six of the most common causes of VFD failure and what you can do to avoid them.
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VFD Accumulation
This is the most common cause of VFD failure. The buildup is nothing more than an accumulation of dust mixed with plant moisture that contains oil, moisture, and metallic particles.
When dust accumulates in your VFD, it attracts extra moisture and restricts airflow, both of which are required for the drive to function properly. Finally, more moisture causes more heat to be generated by the VFD to counteract the effect of moisture, resulting in a series of unfavourable events. This will cause your VFD to gradually stop working, followed by a complete stop.
It is critical to clean the entire device on a regular basis if you want to avoid this problem. Ascertain that there is no possibility of dust accumulation within or outside the device.
Aside from regular cleaning, it is critical to use the appropriate VFD for the plant environment. If your plant environment is more humid, it is best to use sealed VFDs rather than those with side-vents for cooling.
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Overheating
As previously discussed, “buildup” causes a significant amount of overheating. Your VFD may also overheat if the current supplied exceeds the rated level of the drive or if your setup has loose connections.
Excessive heat causes blown capacitors and other critical VFD components. It can also cause shorts that do not blow fuses but are powerful enough to shut down the controller.
The most common way to avoid this problem is to use temperature probes to inspect all of your connections in the drive and motor. Always ensure that the temperature meets the OEM’s specifications. Additionally, keep your environment clean and well-ventilated to avoid buildup.
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Moisture Abundance
Moisture in the drive causes corrosion, which damages the circuit boards. If your VFD runs continuously, it generates enough heat to prevent internal condensation.
Dehumidifiers can be used to prevent excess moisture, but make sure they are not dripping near electronic equipment. Choosing a VFD with a sealed housing can also help you deal with this problem.
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Tight Connections
If your VFD begins to behave erratically, it could be due to loose connections in the circuit. Heat cycles and vibrations over time frequently cause loose connections, resulting in dangerous arcing.
You can avoid this problem by regularly monitoring the various components of the VFD. Examine the circuit board for bulging or leaking capacitors, damaged fans, corrosion, or traces.
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Using the Incorrect Motor/Machine
If you connect your VFD to an incompatible motor or machine, it will inevitably degrade its performance, if not immediately. Some machines perform well with a soft starter rather than a VFD.
Before connecting your VFD to the device, always double-check the compatibility of the motor/machine.
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Ignoring warnings
Finally, the most common cause of VFD failure is ignorance. If you ignore the early warning signs, a relatively minor problem will grow into a much larger one with far-reaching consequences.
As a result, it is best to begin with preventive measures and seek AC VFD repair service as soon as you notice any irregularities in your device.
