VFDs offer cost-effective benefits for plants

Variable frequency drives (VFDs) are designed to reduce energy usage by controlling the speed of the motor and can offer cost-effective benefits for plants.


Variable frequency drives (VFDs) are designed to reduce energy usage by controlling the speed of the motor and can offer cost-effective benefits for plants. Courtesy: L&S ElectricMost business owners are aware of the high cost of operating electrical motors, but there are ways to reduce the costs. Improving the efficiency of an electric motor will save money in the long run, but it is important to understand that not every choice is going to be the right choice for every application.

An example of one way that many businesses can save money in energy costs is through installing variable frequency drive (VFD) technology. VFDs are designed to reduce energy usage by controlling the speed of the motor. While useful, they aren't always the best solution. There will be cases when VFD's cost and installation overshadow the savings they can provide to companies.

Understanding VFD technology benefits

A VFD's primary benefit is adjusting the speed of an ac motor by adjusting the available voltage. When the speed is adjusted, it helps to improve the efficiency of the motor, primarily by adjusting the output of the pump to match the flow and pressure requirements.

Any pump system that has a dynamic demand is a good choice for installing a variable frequency drive. If the pump operates at a lower flow than what is possible from the ac motor, controlling the motor with a VFD considerably reduces the energy consumption.

Installing a VFD can also extend the life of the motor by reducing mechanical wear, which, in turn, reduces maintenance costs, replacement costs, and can keep the motor running at high efficiency.

Is a VFD needed for the application?

A VFD is not always going to be the best choice for every design. Energy and cost savings need to be calculated to determine if it beneficial. This requires the operator to determine the minimum to maximum pump operation, estimate how long the pump would run at various speeds, and estimating how much energy is used at each flow rate.

When considering the costs associated with VFD installation, the operator also needs to consider the cost of the VFD and any potential rebates offered through the utility company for installing it. Factor in any reduction in expenses for maintenance or replacing the pump due to extended pump life from operating at lower speeds.

During a new installation, the benefits of a VFD are usually obvious. In a retrofit, however, there may be additional factors to consider, such as a larger footprint than a motor starter as well as the cost of power cables that may be necessary for the installation as well. In many cases, VFDs can help facilities save money once they are installed and utilized to their fullest potential.

- David Manney is a marketing administrator at L&S Electric. This article originally appeared on L&S Electric Watts New BlogL&S Electric Inc. is a CFE Media content partner.

The Top Plant program honors outstanding manufacturing facilities in North America. View the 2017 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
SCCR, 2018 Maintenance study, and VFDs in a washdown environment.
Welding ergonomics, 2017 Salary Survey, and surge protection
2017 Top Plant winner, Best practices, Plant Engineering at 70, Top 10 stories of 2017
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Setting internal automation standards
Knowing how and when to use parallel generators
PID controllers, Solar-powered SCADA, Using 80 GHz radar sensors

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me