Variable frequency drives are probably one of the greatest inventions in modern automation. If you aren’t using one of these things yet, trust me you will be soon. They are always getting less expensive, easier to use, the applications are virtually endless. Now you can control the speed and the direction of the motor and save money at the same time. These things are instrumental in a lot of different applications and therefore, their uptime is critical. As you may know if you ever had to replace one before, it could be a little cumbersome to replace. It’s always really a race against the clock, because it almost certainly means a motor somewhere is not running which is probably meaning some downtime for you.
So the first thing you always want to remember about VFD uptime is that heat is the number one VFD killer, or heat is the number 1 killer for any piece of electronics for that matter, especially VFDs. These components you have to remember have high voltage running through them, so it could be 480-600 volts if you are in the Canada market running through them and they produce a lot of heat. There are fans inside these things that are designed to cool them. They also have massive heat syncs on the back that are used for heat transfer to the cabinet or surrounding pieces to keep them cool. The one thing you always have to remember is you need to let your VFDs breathe. They have to stay cool. Keep the fans running, always keep the fans running. The first thing that you are probably going to see that will fail on a VFD is the fan, because it’s always running. Anytime the VFD is on, the fans are running constantly. So you need to make sure you have spare fans on the shelf, you know how to replace them, and you maintain them. Make them part of your preventative maintenance program. Check and make sure they are running. Also, the heat syncs themselves can get very dusty, and that dust can build up a lot of that heat so that it can’t transfer heat properly and they will get too hot. Always clean your heat syncs.
1. There are fans forcing air through the internals. Dust can build up just like a PC at home. What do you do to mitigate that? You get a can of compressed air and blow that stuff out of there every now and then. Make sure that you keep a VFD cool and it will always be happy.
2. You want to protect your drafts from heat and contaminants, such as dust or particulate that may be in your air because of whatever process is going on in the nearby environment. You want to make sure the cabinet that these are installed in or at least the environment of the room they are in is a controlled environment. Make sure it’s not going to get too hot. If you are going to put it in a cabinet make sure the Nema or the IP rating of the cabinet is suitable for that environment to keep the contaminants from getting to this piece of equipment.
3. You always want to use proper electrical filters whenever possible. There are filters that are designed for use of both line side, which is between the power company and the drive, and load side, which is between the drive and the motor or the load. There are inductive and compassitive type filters as well as RFIEMI type filters that are designed to help these things, help protect these things from power spikes, electromagnetic noise that may damage the input or output side of the drive or electronics. So always try to use proper electrical filters. It may cost you a little more in the beginning but you will be a lot better off in the long run because it will prolong the life of the VFD itself.
4. You always want to properly maintain the load that this motor is connected to. For instance, if you are not properly maintaining a motor and the motor burns up and the insulation melts inside the motor because it gets too hot, maybe because you didn’t grease a barring. It could cause a short. A short is going to damage the output of this drive and could cause the drive itself to fail. So make sure you are always properly maintaining downstream equipment, the load that the drive is hooked up to.
If you have any more questions about this always feel free to contact us. We have application specialists that can help answer questions as far as how to properly size them, how to properly size the cabinets that they are installed in, the environments they go in, as well as the electrical filters I mentioned, best practices to use when installing those. You can also find a lot of information on our website innovativeidm.com. This is where you will find our knowledge center. There is going to be white papers best practices listed there that you would want to use when selecting drives and components both upstream and downstream from the drive to help increase uptime. After all Innovative-IDM is Home of the Legendary Customer Experience.