Common causes of VFD failure

 

Keeping Your VFD Maintained to Reduce VFD Failure

The first thing you should know when purchasing a VFD is to keep it clean, cool, and dry. If you follow these three recommendations, the life of your VFD will be greatly extended. Unfortunately, there will come a time when your VFD will encounter a problem (hopefully many years down the road). This article will cover some of the most common causes of VFD faults and failures and provide some tips and tricks to prevent them to keep your equipment in tip-top shape.

Poor Environment

VFDs are built like computers, and computers are extremely susceptible to dust, debris, moisture, and overheating. If you are using a VFD in an area that is consistently taking in dust, debris, or moisture the operating life of your VFD will be shortened.

In environments with high humidity, such as wastewater treatment plants, your VFD is at risk for circuit board corrosion from moisture being sucked into the cabinet through the cooling vents constantly. This, compounded by possible infrequent use, can enable moisture to build up without time for heat and ventilation to dry it out. To avoid issues caused by humidity, ensure that the operating environment and storage space for your VFD are clean and dry, and consider a dehumidifier to dry out the air (ensure the dehumidifier does not leak near any electronic equipment). For extreme humidity or wash-down environments, a NEMA 4, 4X, or 5 enclosures may be necessary.

Loose Connections

If you feel like your VFD is not performing quite like it used to, loose connections or aging components could be the culprit. High levels of vibration and heat production are the two main causes of loose connections and premature aging of certain components. This can lead to dangerous electrical arcing within the circuitry. Arcing can cause issues with other parts of your equipment and create a dangerous working environment for your employees or technicians. Loose connections can cause permanent damage to your equipment if not addressed as soon as possible.

Wrong Equipment

Unfortunately, you may be recommended the wrong VFD for your equipment. If you accidentally connect your VFD to an incompatible motor or machine, performance degradation is inevitable. Always make sure you double or triple-check the compatibility of your motors/machines before you connect your VFD to the device.