Purvis Industries

Article By: Don Lovella, Triad Automation Business Development Manager

There are many reasons our customers use variable frequency drives, but probably the most popular reason is to control the speed of their electric motor. While other customers might want to use a VDF to start and stop their machine in a specific location or time. There are other customers who might want to use a VFD to minimize the impact on the mechanical system. VFD's accomplish all these tasks by controlling the speed, position or acceleration of an electric motor. While this all sounds great, there is still more a VFD can do for you and that is save energy! Saving energy is probably the most overlooked benefit of using a VFD.

For example,  a typical variable torque application such as a fan or a centrical pumps energy consumption can be reduced approximately 50% by slowing down the motor just 25%!

Here are some interesting facts about electric motors.

• Electric Motors consume approximately 28% of the world's total electrical energy production.
• The cost of an electric motor is approximately 1% of the total cost of ownership of an an electric motor while the other 99% is the cost of the electricity to operate that motor.
• Approximately half of all electric motors installed today could reduce energy consumption with the addition of a VFD.

This means there are literally hundreds of thousands, if not million, application within our industry that could benefit by the addition of a VFD! I'm sure by now you're thinking to yourself this all sounds great, but the I'm not sure we can afford the expense of adding VFD's. What if I were to tell you that electrical utility providers offer rebates to their customers to install VFD's and save energy? This sounds crazy, but on average the rebate from an electrical utility provider for a VFD package install is $125 a horse power. I know you're thinking I don't have the time to search through my utility providers website to find the rebates. I have an answer for that as well. There is a website 'www.dsireusa.org' that we have used for many years to assist our customers in locating rebates provided by their utility provider. All you have to do is enter your zip code in the search field and ti will take them to a page that shows rebates provided by their utility providers.