Nothing lasts forever, but our top 10 preventative maintenance tips for variable speed drives helps you get the most out of your drives for as long as possible. We recommend planning a service for your drives every 5-8 years, but in the meantime following these tips should ensure uninterrupted service.
Vacuum dust & dirt
In a production environment dust and dirt can easily clog up heatsinks. This can cause the inverter to overheat and internal components to malfunction. Dust and dirt can also absorb moisture which can contribute to inverter failure. Simply running an ESD vacuum cleaner over the heatsink or blowing out the heatsink with compressed air is a good preventive maintenance measure and can add years to the life of your inverter. Don’t forget to lock fans.
Check or replace air intake filters on larger drives
To ascertain how often you should be checking your air intake filters, frequently check them when the drive is new. This should give you an indication of how often they need to be cleaned and eventually replaced. If you don’t have a dedicated system for planned maintenance simply set a reminder in your Google Calendar to get an email when it’s due.
Make sure the inverter’s fans are operating correctly – freely rotating & no noise
Malfunctioning fans are a major cause of inverter failure. Fans help cool the internal components found within the VSD including electrolytic capacitors. The capacitors are prone to drying out much faster when the internal temperature is too high and can lead to the drive developing intermittent faults such as tripping out after a period of time. Don’t underestimate the effects of heat on an inverter drive, many manufacturers recommend derating the output by up to 15% if the temperature is higher than just 40°C.
Ensure the control panel is well ventilated
Keeping the control panel well ventilated is necessary to ensure sufficient air flows through the drive to keep it cool. Letting your drive overheat can cause all sorts of problems, from capacitors drying out much faster to complete failure of the VSD.
Check control & power terminals are tight
My Dad always said “to do it right make sure it’s tight.” This is something many people forget to include in their preventative maintenance plan. Loose connections can be attributed to many problems including extra heating and/or arcing, to the extent that connectors can actually be melted down. Other problems that can be caused due to loose control and power terminals include intermittent operation and reduced efficiency. It is recommended that the tightness of connections is checked annually.
Backup your drive parameters
Sounds obvious but many engineers do not have backups of their inverter parameters. This means that should your drive one day fail beyond repair, you can commission a new inverter in as little time as possible. For many users, particularly those with complex applications, the parameters are worth more than the drive, so it only makes sense to keep a back up.
Check the resistance of contacts on the drive’s supply contactors
Any electromechanical and switching parts are subject to wear, as the contacts become pitted they can lead to an imbalance on your supply causing problems with your AC drive’s bridge and DC bus.
Remove LCD programming keypads when not in use
Leaving an LCD programming keypad attached to a drive is a sure fire way to reduce the keypad’s lifespan. As many of the keypads stay on constantly, the LCD screen eventually dies. This is because they usually have a lifespan of a certain amount of hours and will burn out once they reach the set time. Removing the keypad when not in use will prolong the life so that when you do have a fault with your drive you don’t have to wait for a new keypad before diagnosing it.
Make sure where your drive is instaled is clean and dry
This is especially important for drives with an IP00 or IP20 rating. Drives with these ratings are particularly exposed to contamination from dust. Too much dust can restrict airflow which in turn reduces performance of fans or heatsinks – this can eventually lead to the failure of your drive.
Keeping a drive with a low IP rating in a moist environment is also another sure fire way to lead to inverter failure. Moisture getting into the drive can cause a range of problems, most notably corrosion to the circuit board.
Service your inverters every five to eight years
Sending your variable speed drives to Northern Industrial every five to eight years can significantly increase the lifespan. By booking a service, you can schedule when it is convenient for you to remove the inverter from operation. During a service we complete all of the above steps as well as replacing components which have a limited life like fans and capacitors.
If you would like to book a service for your variable speed drives or any other automation equipment, give us a call on +44 (0) 1254 673747 for a no obligation chat.