Preventive maintenance is critical for keeping your equipment in peak operating condition, and variable frequency drives (VFDs) are no exception. These devices are major investments, so you must keep them working correctly to make a strong return.
Maintaining a consistent preventive maintenance schedule can help you reduce your risk of malfunctions and prevent costly repairs to keep costs low and ensure high performance.
A Basic Overview of VFD Structure
Understanding the drive’s essential components can make it easier to plan your preventive maintenance workflow. Those components include:
Power supply: The drive must be connected to a power source to function.
Rectifier: Also known as the converter, this section consists of six diodes that convert the incoming alternating current (AC) into direct current (DC). The diodes also keep the current moving in one direction toward the DC bus.
DC bus: The direct current travels across the DC bus through a series of capacitors, eliminating any AC ripple that may negatively impact the current’s quality.
Inverter: The smoothed DC moves through a series of inverter power devices, which may include standard transistors or insulated-gate bipolar transistors (IGBTs). These devices convert the current back to AC, then send it to the electric motor.
Control circuitry: The control circuits gather information on the drive’s operation and provide signals to its internal mechanisms to ensure consistently high performance.
Cooling system: VFDs have more intensive cooling requirements than other electric motor controllers. Depending on the model, this cooling system might use air or liquid cooling techniques to keep the drive operating at safe temperatures.
Electric motor: The electric motor is the last step in the VFD. The speed at which current travels in the drive affects the speed at which the motor will function.
NEMA 1: These units feature a series of side vents to enable better airflow through the device, which is why they are exclusively for indoor applications. While these vents block out large objects like insects, other smaller particles, like dust, can enter and build up inside the drive vents.
NEMA 12: These units are completely closed, with no open vents anywhere on the surface. As a result, they require less intensive cleaning and maintenance.
The Importance of Regular VFD Maintenance
Some of the benefits of committing to a regular VFD maintenance schedule include:
Extended drive life span: Routine maintenance can help you prevent problems from developing, reducing your risk of malfunction and keeping the drive working properly.
Reduced downtime: Catching electrical issues before they escalate into serious problems can help you prevent unexpected downtime and plan for service, supporting boosted productivity.
Cost savings: Preventive maintenance can help you cut costs associated with VFD repairs, excessive downtime and low operating performance.
Enhanced performance: Keeping your VFD in excellent condition helps maintain high energy efficiency in normal operation, which is essential for generating a strong return on investment.
It’s also important to mention the potential consequences of neglecting routine maintenance for VFDs:
Debris buildup: Dirt, dust and other particles can accumulate in your drive’s vents and cooling systems, which can lead to overheating and impede drive function.
Corroded circuit boards: Exposure to moisture can cause corrosion to develop on the drive’s circuitry, which can degrade the circuit boards and cause a decline in performance.
Overheating: Failure to regularly clean your NEMA 1 VFD can lead to debris buildup inside the drive, potentially blocking airflow through the unit and causing a malfunction.
Loose connections: Power connections can loosen over time due to vibrations and drive movement, causing overheating and premature failure.
Malfunctions or failures: Overload trips, voltage drops and capacitor faults become more likely the longer you go without regular maintenance.
Routine VFD Maintenance Practices
Some key steps in your preventive maintenance rotation include:
Visual inspections: Examine all surfaces of the drive for signs of corrosion, condensation and debris buildup. You can usually solve most of these issues on-site with minimal equipment.
Cleaning procedures: Cleaning the VFD’s control panel and vents with a vacuum is the most effective technique to remove dust and debris, though you may not need to perform this step if you have a NEMA 12 drive.
Electrical checks: Examine the connections between the drive’s internal components to identify looseness. If necessary, adjust the connections according to the original equipment manufacturer (OEM) specifications.
Firmware updates: VFDs use programming software to control drive settings according to user input. Keeping this software updated is essential for effective operation as well as accurate monitoring, streamlined troubleshooting and smoother startups.
Cooling system maintenance: Remove any dust and debris from the cooling system using a vacuum, and check to make sure all fans and liquid cooling equipment are in good condition.
Performance monitoring: Ongoing performance monitoring helps you determine how often you’ll need to prioritize upkeep, which is key for minimizing downtime. Your personnel should check drive performance at regular intervals and document their findings to keep maintenance technicians up to date on potential areas of concern.
The specific intervals at which you should perform these steps will vary depending on your drive’s make, model and age. Consulting with a professional can help you create a maintenance schedule that works for your drive and your facility.
Advanced VFD Maintenance Practices
You may also want to perform more intensive maintenance procedures to ensure your drive remains in peak condition. These techniques can include:
Thermal imaging: Maintenance professionals may use thermal imaging cameras to check the VFD’s wiring for hot spots, which can indicate where problems are beginning within the device.
Predictive maintenance: These systems are equipped with artificial intelligence (AI) algorithms that analyze historical repair and maintenance data to accurately predict when your VFD will need to undergo inspection.
Staff training: Safely handling industrial electrical equipment requires extensive training and practice. Personnel safety training services can help you ensure your team is prepared to protect themselves from the risks of malfunctioning VFDs.
These techniques usually require advanced equipment and special expertise, so you’ll need to hire a reliable electrical professional to perform them.
Choose Industrial Electrical Company for Reliable VFD Repair and Maintenance Services
If you’re looking for assistance installing and maintaining your facility’s VFD, Industrial Electrical Company is here for you.
Our team of union electricians has extensive experience dealing with VFDs, so you can rest easy knowing your equipment is in good hands. In addition to installation and advanced maintenance procedures, we also offer variable frequency drive repair services.
You can depend on us to answer your call no matter what time of day you need help. At Industrial Electrical Company, we’re your one-stop shop for everything VFD.
Our motor shop is located right in the Central Valley and can complete any job from total welding services to custom modifications. To learn more about our services, classes and products, contact us online today.
