Comparing VFD Benefits: Why Choose Variable Frequency Drives?

When You Should Select VFD?

Choosing a variable frequency drive over other device often depends on your application. Devices like, soft starters are smaller and less expensive when compared with VFDs in larger horsepower applications. Larger VFDs take up more space and are usually more expensive than soft starters.

Even though a VFD is costlier in advance, it can offer energy savings of up to fifty percent, thus giving more cost savings over the life span of the equipment. Speed control is another advantage of a VFD, because it offers consistent acceleration time throughout the entire operating cycle of the motor, not just during startup. VFDs can also offer stronger functionality than other devices, as well as digital diagnostic information.

It is important to note that a VFD can initially cost two to three times more than other devices. Therefore, if constant acceleration and torque control is not necessary, and your application requires current limiting only during startup, a cheaper device like soft starter may be a better solution from a cost standpoint.


Benefits of VFD are:

  • Energy Savings: Creating variance in the speed of the motor provides energy savings.  In several motors VFDs are used to reduce the energy used by the motor. Meaning a 30% decrease in the motor’s speed leads to an almost 65% reduction in energy used.
  • Lower Demand Charges: By lowering the amount of energy your building uses during its peak demand period, you will lower your demand charge, which is another significant part of your electric bill.
  • Longevity of Equipment: A VFD provide a soft start to the motor and permits it to rise up and down.  A soft start meaning that the motor speeds up progressively than all at once, utilizing smaller energy than a general motor’s start off.  These variations to motor function decreases the wear and tear on the parts of the motor, prolonging the life of equipment.
  • Lowered Repair Costs: There will be lesser repairs and replacements required on parts and equipment, as wear and tear to the motor and equipment are decreased through a soft start and the ability to adjust speed as required
  • Diagnostic implications: Many VFDs can be connected to facility management systems to help compile information about the system.


Where is VFD Panel Installed?

There are both physical and electrical installation basics to be aware of when using a VFD.

  • When mounting the VFD on a back panel, be sure to check the specifications.
  • It is common for multiple devices to be installed in one location, but all VFDs need proper air flow, so check the installation instructions carefully when laying out a control panel.
  • Mount the drives vertically.
  • Some drives can be mounted with no clearance, but it’s common to have a minimum side-to-side spacing of 50 mm or more and to have vertical clearance above and below the drive of 100 mm to 150 mm.
Written by CoreSystems

Chosing VFD Over Other Drives and VFD’s Benefits