Hooked on Hydronics Blog

Does Your System Need Shaft Grounding Technology?

Posted by Kelly Patterson on Nov 16, 2018 9:40:40 AM
Find me on:

We are huge advocates of utilizing VFDs to control AC motors in most instances.  It isn't often that we need to run a pump motor at full speed, so we can reduce our energy consumption (lower costs) while being a little kinder to our motors by installing VFDs in our systems.  Rarely in life do we encounter anything that is flawless, however, and VFDs are no exception.  They do lower our operating costs and can increase system performance, but they also create shaft voltage. 

Simply put, VFDs induce voltage onto the shaft of the driven motor.  This can cause pitting, fluting and, if left unchecked, bearing and motor failure.  Addressing motor failure has become a significant problem in HVAC systems and in industrial systems. 

"The largest motor manufacturer in the United States has cited eliminating drive-related motor failures as its number one engineering challenge."
(from AEGIS white paper, Preventing VFD/AC Drive-Induced Electrical Damage to AC Motor Bearings)

We are here to help you solve this problem.  Well, actually, a company named AEGIS is here to help you solve it.  While Heat Transfer Sales does not represent AEGIS products, we are intent on helping engineers solve system problems.  From what we've seen, AEGIS products address this problem nicely.  AEGIS offers a variety of shaft grounding rings designed to divert bearing currents to ground. They even offer a few free resources for engineers, including technical white papers:

White Paper:  Preventing VFD/AC Drive-Induced Electrical Damage to AC Motor Bearings

White Paper: To Be Considered "True Inverter Duty," Motors Need Bearing Protection

Click here for the full list of white papers and technical resources available from AEGIS.

Take a look at this short video before and after AEGIS Ring installation:

 

The benefits of using VFDs are numerous, but we want to take care to protect our motors from any side-effects created by utilizing VFDs.  If you need questions answered about VFD selection or other equipment, please contact your local manufacturer's representative.  We are here to make your life a little easier.

 

Click here to learn about the Q-Link VFD with easy smartphone start-up,  troubleshooting and reporting

 

 

 

 

 

 

 

Topics: HVAC Design Tools, Variable Frequency Drives, Energy Savings

Why we blog

At Heat Transfer Sales of the Carolinas, we are invested in the success of our customers.  And we believe in the products we represent.  We use our blog posts to educate and answer questions about hydronic HVAC and engineered plumbing equipment and the industry in general. 

We are dedicated to:

  • Helping our customers find solutions
  • Innovative thinking
  • Serving as true partners in the HVAC & plumbing industry
  • Representing the latest high-performing equipment

Subscribe to Blog

Recent Posts