Variable frequency drives (VFDs) require specific storage conditions and maintenance to perform well and last long. Understanding the proper ways to protect VFDs can help you prevent damage, minimize equipment downtime and ensure your VFDs operate at top performance.
Variable frequency drives are electric motor controllers. They drive electric motors by varying the motors’ voltage supply and frequency. Manufacturers use variable speed drives to improve electrical motor efficiency.
VFDs offer excellent motor control, so you can operate your systems at lower speeds and with a greater unity power factor. A VFD’s power factor indicates how effectively it utilizes electricity to generate useful equipment output such as lighting, motion, heating or cooling.
Lower operational speeds and a greater power factor can reduce operating costs, helping you save money and increase your return on investment over time. Optimizing and maximizing a VFD’s life span ensure it operates effectively and efficiently so you can receive the greatest return on investment possible.
Protecting operating VFDs is essential, but it’s also crucial to keep and protect a spare VFD. If you rely on your equipment to operate regularly, a spare VFD can help you prevent machine downtime should your operating VFD malfunction or require repair. You can utilize a spare VFD when necessary, but protecting the spare VFD is equally important as maintaining the operating VFD.
To extend your VFD’s life span and ensure it operates properly, consider the following tips for protecting VFDs:
A properly sized VFD can effectively handle the required torque in any situation. VFD manufacturers have design resources and the necessary experience to size VFDs according to ambient conditions and loads. Talk with your VFD manufacturer to ensure they’re aware of your applications and needs.
Consulting with the manufacturer helps you ensure your VFD can meet your facility’s needs. The VFD model you need depends on the following factors:
Professional installation is crucial. An experienced technician provides the following benefits:
A professional technician also ensures they install VFDs with the correct cables, fuses, load retractors and filters. Installing a VFD with the correct sizes and types of cables, fuses and external components is essential for proper operation and longevity. Experienced technicians wire VFDs to meet NEMA 4 and NEMA 12 ratings.
You should regularly inspect your stored and operating VFDS to ensure no complications are present. For example, forklifts or other equipment may bump a stored or operating VFD, causing potential damage, or a stored VFD may lack important components if an employee used a stored component to repair an operating VFD. Scheduling professional inspections is ideal because a trained technician can identify potential complications and perform repairs properly.
VFDs last longer and remain in good condition when you maintain them properly. Check your VFD’s manual for recommended maintenance intervals, and plan equipment downtime. Thoroughly inspect and clean your VFD to detect any potential complications and remove objects that may prevent heat dissipation.
An electrolytic capacitor is one of the main VFD components that require regular maintenance. Electrolytic capacitors are common in low- and medium-voltage drives, and they contain an electrolytic gel. The electrolytic gel can dry out if you leave the VFD unused for over a year, which can lead to spontaneous combustion. Energizing or reforming a stored VFD annually prevents the electrolytic capacitor from drying out.
If a year passes without energizing the electrolytic capacitor, you’ll need to reform the capacitor before using it. The best way to keep your stored VFD capacitor in shape is to rotate your equipment when you perform annual preventative maintenance. Rotating your equipment is ideal because you cannot reform capacitors on printed circuit boards.
Some VFDs contain dry film capacitors that remain in good condition without energizing, so it’s important to know what kind of capacitor your VFD contains.
VFDs generate pulse-width modulation (PWM) waveforms to produce synthetic AC waveforms. PWM waveforms can cause high voltages, but a proper VFD motor can handle high voltages and protect the VFD’s components from damage.
VFD motors contain adequate insulation to protect against high-voltage strikes, but you should ensure you choose the right motor based on the following factors:
Consulting with a motor manufacturer is important when purchasing a VFD. Ensuring you have the best motor for your VFD and its applications helps it last longer.
Train your equipment operators and maintenance staff on how to operate and protect VFDs properly. Employees who work with or maintain VFDs should understand how they operate so they can identify abnormalities and schedule maintenance or repairs when necessary.
Train each individual so they understand how to do the following:
Employees should also understand basic VFD safety guidelines to prevent damage and injury.
A variable frequency drive can last up to 20 years in proper storage conditions. Without proper storage conditions, VFDs typically last three to five years. NEMA 1 or NEMA 12 rated enclosures provide the ideal storage for VFDs.
Storage conditions can significantly affect a VFD. When you keep a spare VFD in long-term storage, you should maintain the following conditions:
Moisture, dust, oil, heat and animals can potentially damage VFDs, so it’s essential to keep your storage space clean, dry, cool and rodent-free. Check the space frequently to ensure it’s clean and free of nests. You can check your VFD’s manual to determine the ideal temperature for your storage space.
Regular maintenance and a protective operational or storage environment help VFDs last long and work effectively. Industrial Electrical Company offers professional electrical installation and maintenance services to extend your equipment’s life span and ensure it operates efficiently.
We answer the phone 24 hours a day, so you can depend on us for emergency maintenance and repairs whenever you need assistance. Contact Industrial Electrical Company to learn more about our services and how we can help you maintain and protect your 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.