VFD drives are heart of motor control panel when it comes to starting and controlling 3 phase AC motors.
In lot of cases VFD are housed in vfd electrical panels to provide electrical, mechanical, environmental protection to VFD, motor, electrical system and user.
These panels require regular maintenance to work trouble free.
Here are Some Maintenance Tips
- Always inspect and clean or replace intake and exhaust filters, check if fans are working fine and the thermostats are calibrated correctly.
- Check any signs of VFD drive overheating, Inspect VFD for any dust or debris, clean if required.
- Check any sign for excessive humidity or moisture in vfd electrical panel, If any issues try to adjust the air flow, change the location of intake filter or panel or add anti- condensation heaters
- Check for loose connections, abnormal noise and check if motor is operating fine.
Why use VFD Electrical Panel & how it works?
- VFD electrical panel is a packaged solution which is designed and built as per application and site requirement.You should be always using VFD electrical panel instead of loose VFD due to following reason,
- VFD electrical panels equipped with correctly sized over current protection devices like breakers or fuses and provide short circuit protection to VFD drives load conductors and motors.
- Input, output reactors or harmonic mitigation devices fitted within vfd electrical drive panels provide harmonic protection to electrical network, VFD and motor.
- Airflow fans, Intake/exhaust filters, air conditioners provide right dust free cooling to VFD’s so they can last long.
- When VFD’s are equipped in outdoor enclosures with properly sized heaters and other accessories these units can be installed outdoors even in harsh weather conditions.
- As all the required components are previewed and tested in the panels it is very easy for electrician to install and connect them.
- Pre packaged VFD panels are very safe and user friendly as panel are equipped with main lockable disconnect, operator switches, warning lights, buzzers and displays for easy operation and monitoring.
VFD Maintenance: Key Aspects
VFD’s are made of lot of different parts like sensitive electronic boards, heat producing power electronic devices and airflow fans so VFD’s require regular maintenance even when installed in vfd electrical control panels.Regular visual inspections for any signs of wear, damage, abnormal noise, wet, humid and dusty environment.Check for loose connections, overheating, and signs of corrosion.
As VFD’s have a cooling system including heat sinks, airflow fans or liquid cooling for cooling VFD’s. Keep all the filter and heat sinks clean and obstruction free. In case of liquid cooling make sure the pump and lines are working fine. Fans are starting when cooling needed and spin smoothly without any abnormal noise.
Keep the VFD’s software and firmware up to date to ensure performance, reliability and network security. Follow the manufacturer’s recommendations and guidelines for updates.Ensure that personnel responsible for maintaining and operating the VFD are adequately trained and qualified to perform the required tasks.
Also Read: The Basics of Variable Frequency Drive Panel
1. Keep VFDs Clean
- VFD are equipped with sensitive electronics boards, moving parts, heat producing power electronic switching devices, heat sinks.
- VFD’s should be kept dry and clean to avoid any corrosion, electrical shock, ground faults, electrical or mechanical damage to internal parts.
- Keeping VFD’s clean can assure trouble free operation, long life of vfd and maintaining the warranty.
2. Keep VFDs Dry
- VFD’s have electrical connections and electronic boards within them so it is very important to keep them dry.
- If the VFD is installed in a damp or humid environment following is recommended to keep them dry.
- Consider using dehumidifiers to keep the air dry.
- Move the location of the VFD.
- Bring dry air in the area and exhaust the humid air out.
- Install the VFD’s in appropriate enclosures with anti-condensation heaters.
3. Keep VFDs Cool
- Power electronics within a VFD produce quite a bit heat when running, to dissipate that heat VFD’s are equipped with air flow fans and heat sinks.
- For that reason, VFD fans, filters, heat sinks and any other associated parts should be kept clean and obstruction free maintain an adequate air flow around these parts to dissipate heat to keep them within their operating temperature range.
4. Keeping VFD Connections Tight
- Keeping any electrical connections tight within an electrical system is important for safe and proper operation but especially when it comes to VFD’s it is very important to keep the connections tight due to many reasons.
- Loose connections can damage the VFD, driven motor or the electrical system it is connected to.
- Mostly VFD drives have built in capacitors and drives are connected to motors which involves high in rush currents and loose connection can create an immediate fire.
Also Read: What are the Advantages of Using a Variable Frequency Drive?
Simple check-ups and maintenance
There are so many simple checks you can do to ensure trouble free and long-lasting operation of vfd dives.
Here are some regular checks recommended
- Perform visual inspection to see it is dry and clean.
- Check for any signs of overheating like smoke, smell, discoloured components, alarms etc.
- Loose connections, frayed, broken or cracked wired or components.
- Abnormal noises from VFD’s, fans or any other components
- VFD is working under specified electrical and mechanical parameters.
- Fans turning on when required and filters are clean and obstruction free.
- VFD software and firmware up to date
- Check if there are any recalls from manufacturer.
- Make sure VFD have been running regularly if not, after certain period it may need capacitor reforming before running again
Filters are provided to supply clean and dust free air to VFD panel. Often vfd filters get clogged with dust or other element and don’t supply adequate air supply to drive causing overheating and failure.
- Check the filters often, Replace or clean when needed.
- When replacing filters make sure it is the same size, mounting and material.
- Aluminium or certain type filters can be washed to clean them.
- If the filters are getting dirty very often, try to find an adequate filter material which will perform for longer periods, make sure the output air flow is same as the existing filter when clean.
- If the air flow of the new material is lesser than existing filter, you could always think about oversizing the filter area to maintain required air flow.
2. Cooling devices
VFD’s are equipped with different type of cooling techniques to dissipate the heat produced by switching power electronic devices to avoid overheating.
- Pretty much all the VFD drives have heat sinks, active airflow fans for heat dissipation.
- Some of the bigger drives equipped with air conditioners or liquid cooling systems.
- For the proper operation of the drive it is very important that cooling system is always performing well to keep the power electronics cool.
Here are some tips
- Filters and heat sinks are clean and dry.
- Fan are running obstruction free when needed.
- Air conditioners are supplying conditioned air and no air leaks in the enclosure.
- Water pumps are running when needed and no leaks in piping.
3. Routine visual inspections
- Routine visual inspections can prevent shutdowns and failures.
- Make sure VFD or the panel is clean and dry.
- Look for any abnormal noise, loose connections, frayed wired, overheating, discoloured components, smoke, burning smell, vibration, broken parts, corrosion, condensation, sparks, dirty air filters,
- Check VFD keypad or drive panel HMI’s or pilot lights, for electrical readings, messages or alarms for any warnings.
4. Verifying Component Life
- VFD’s are made of a mix of components like sensitive electronic boards, switching power electronic devices, electrical components like contactors, connectors, fans and capacitors.
- Monitor the performance of the VFD over a period of time, measuring variables such as input voltage, output voltage, current and temperature
- Compare the measured values to the manufacturer’s specifications, looking for any deviations that may indicate a problem.
- Most of the VFD components need regular maintenance to maintain the component life span, especially fans need regular lubrication and capacitors need reforming when not used for longer period of time to perform well and maintain life cycle.
Also Read: Solution Control Systems Brings You the Highly Advanced Variable Frequency Drive Panels
5. Capacitor Reforming
- Capacitor reforming is a process of rejuvenating an electrolytic capacitor by restoring its original capacity and reducing leakage current. Over time, electrolytic capacitors can dry out, causing a loss of capacitance and an increase in leakage current, which can result in decreased performance or failure of the capacitor.
- The reforming process involves applying a gradually increased voltage over a period of time to capacitor. This can be achieved with a special purpose cap reformer power supply which allows the capacitor to reform and rebuild its oxide layer.
- The reforming process must be performed by a trained professional and a cap reformer. It is important to follow cap reformer and VFD or capacitor manufacturer’s instructions and guidelines when reforming capacitor.
- However, reforming may not always be successful in restoring the original capacitance or reducing the leakage current, and in some cases, it may be necessary to replace the capacitor.