--- title: If You Sell Drives, It's Smart to Recommend Motors with Shaft Grounding description: If You Sell Drives, It's Smart to Recommend Motors with Shaft Grounding image: https://blog.est-aegis.com/hubfs/Imported_Blog_Media/Motors-with-AEGIS-Inside-1.jpg --- [![Electro Static Technology](https://blog.est-aegis.com/hubfs/raw_assets/public/public/images/electro-static-technology.svg "Electro Static Technology")](https://www.est-aegis.com/) [![Aegis](https://blog.est-aegis.com/hubfs/raw_assets/public/public/images/Aegis.svg "Aegis")](https://www.est-aegis.com/) - [+1 866-738-1857](tel:+1%20866-738-1857) - [Products](https://www.est-aegis.com/products/) - [AEGIS® SGR – for motors under 500 HP/375 kW](https://www.est-aegis.com/product/sgr/) - [AEGIS® uKIT – for common NEMA/IEC frame size](https://www.est-aegis.com/product/sgr-ukit/) - [AEGIS® RPPR – for reactor recirculating pumps](https://www.est-aegis.com/rppr-resources/) - [AEGIS® EV and EVO Rings - for electric vehicles](https://www.est-aegis.com/product/ev-evo-rings/) - [AEGIS® PRO Series – for motors over 300 HP/225 kW](https://www.est-aegis.com/product/pro-series/) - [Shaft Voltage Testing and Accessories](https://www.est-aegis.com/product/mounting-accessories/) - [Online Product Catalog](https://catalog.est-aegis.com/) - [AEGIS® 2-Year Extended Warranty](https://www.est-aegis.com/product/extended-warranty/) - [Applications](https://www.est-aegis.com/applications/) - [Electric Vehicle Solutions](https://www.est-aegis.com/applications/electric-vehicle-solutions/) - [Food & Beverage](https://www.est-aegis.com/applications/food-beverage/) - [HVAC](https://www.est-aegis.com/applications/hvac/) - [Industrial & Chemical](https://www.est-aegis.com/applications/industrial-chemical/) - [Other Industries](https://www.est-aegis.com/applications/other-industries/) - [Power Generation & Renewable Energy](https://www.est-aegis.com/applications/power-generation-renewable-energy/) - [Transportation](https://www.est-aegis.com/applications/transportation/) - [Water Treatment](https://www.est-aegis.com/applications/water-treatment/) - [Bearing Protection](https://www.est-aegis.com/bearing-protection/) - [Shaft Voltage & Bearing Currents](https://www.est-aegis.com/bearing-protection/shaft-voltage-and-bearing-currents/) - [Fluting & Bearing Inspection](https://www.est-aegis.com/bearing-protection/fluting-and-bearing-inspection/) - [Best Practices & Installation](https://www.est-aegis.com/bearing-protection/best-practices-and-installation/) - [Resources](https://www.est-aegis.com/resources/) - [AEGIS® Bearing Protection Handbook](https://www.est-aegis.com/resources/handbook/) - [IEEE-841, Hazardous Locations, & AEGIS®](https://info.est-aegis.com/technical-codes-and-ieee-841-standards) - [Recorded Webinars Library](https://www.est-aegis.com/resources/recorded-webinars/) - [Installation Instructions](https://www.est-aegis.com/resources/installation-instructions/) - [Videos](https://www.est-aegis.com/resources/videos/) - [Technical Papers](https://www.est-aegis.com/resources/technical-papers/) - [Case Studies](https://www.est-aegis.com/resources/case-studies/) - [Specifying AEGIS®](https://www.est-aegis.com/resources/specifying-aegis/) - [Request Training](https://www.est-aegis.com/resources/training/) - [Product Sheets](https://www.est-aegis.com/resources/product-sheets/) - [About](https://www.est-aegis.com/about/) - [News](https://blog.est-aegis.com/) - [Tradeshows](https://www.est-aegis.com/about/tradeshows/) - [Blog](https://blog.est-aegis.com/) - [Where to Buy](https://www.est-aegis.com/where-to-buy/) - [Distributors](https://www.est-aegis.com/where-to-buy/distributors?type=Distributor) - [Trained Installers](https://www.est-aegis.com/where-to-buy/installers?type=Installer) - [Explosion Proof Installers](https://www.est-aegis.com/where-to-buy/installers?type=Explosion%20Proof%20Installer) - [Motors & Seals with AEGIS® Installed](https://www.est-aegis.com/where-to-buy/oems-with-aegis/) [Contact Us](https://www.est-aegis.com/contact/) - [+1 866-738-1857](tel:+1%20866-738-1857) # If You Sell Drives, It's Smart to Recommend Motors with Shaft Grounding [Home](https://www.est-aegis.com/) » [Blog](https://blog.est-aegis.com/) » If You Sell Drives, It's Smart to Recommend Motors with Shaft Grounding [AEGIS](https://blog.est-aegis.com/author/estaegis) Apr 12, 2018 Variable frequency drive users look to drive manufacturers and reps not only for quality products but expertise. If they don't find the knowledge to fix any problems they run into, they may go to another brand. But more positively, **the more expertise you show, the more you build their loyalty**. And if you can stave off any problems they might later run into, so much the better. One way that drives salespeople and reps already do this is by recommending using inverter-duty motors (with Class F or H insulation) with drives. Drives protect the motor windings from turn-to-turn shorts due to the VFD output's high dV/dt. Some motors, on some drives, in some applications, will be alright with Class B insulation, but **why take the chance?** ## The Problem of Shaft Voltage Burnt out windings aren't the only risk that drives pose to motors. The common mode voltage of the three phases capacitively creates a potential difference between the rotor and motor frame. This so-called [shaft voltage](https://www.est-aegis.com/bearing-protection/fluting-and-bearing-inspection/) can discharge destructively through the bearings, often drastically shortening bearing life. Now, is *every* motor running on a VFD going to have its bearings fail prematurely?  Maybe not, but why take the chance? **Why not just avoid the problem altogether?** The best and easiest way to prevent this premature bearing failure is to recommend that your customers use [motors with AEGIS® Shaft Grounding Rings factory-installed](https://www.est-aegis.com/where-to-buy/oems-with-aegis/). AEGIS Rings discharge shaft voltage safely to ground, channeling the discharge currents *around* the bearings. These long-lived rings protect: - motors from premature bearing failure - your customers from the expense of repair/replacement and associated downtime, *and* - **you** from customers understandably angry that their new motor failed after just a few months Best of all, by warning customers of this problem, and solving it, you will be showing your expertise, and continuing to earn their loyalty.   [![Motors with AEGIS factory installed are available from ABB Motors & Mechanical, WEG Electric, Marathon, TECO, LEESON, GE, and many more](https://blog.est-aegis.com/hs-fs/hubfs/Imported_Blog_Media/Motors-with-AEGIS-Inside-1.jpg?width=680&height=399&name=Motors-with-AEGIS-Inside-1.jpg)](http://est-aegis.com/oem/OEM_AEGIS_List.pdf) Motors with AEGIS factory installed are available from ABB Motors & Mechanical, WEG Electric, Marathon, TECO, LEESON, GE, and many more For more on the problem of capacitively coupled bearing current and its mitigation with AEGIS rings, see our [Bearing Protection Handbook](https://www.est-aegis.com/resources/handbook/). Or even better, you can [request a Lunch & Learn training](https://www.est-aegis.com/resources/training/), worth one Professional Development Hour. [![](https://blog.est-aegis.com/hs-fs/hubfs/Imported_Blog_Media/Lunch-and-Learn-Training-Click-to-Sign-Up-e1519327105871-1.png?width=450&height=51&name=Lunch-and-Learn-Training-Click-to-Sign-Up-e1519327105871-1.png)](https://www.est-aegis.com/resources/training/) [Shaft Grounding](https://blog.est-aegis.com/tag/shaft-grounding), [Motors on VFD](https://blog.est-aegis.com/tag/motors) ### Subscribe To Our Blog ## Read On ### [Marathon Explosion-Proof Motors Available with AEGIS Rings Factory-Installed](https://blog.est-aegis.com/marathon-explosion-proof-motors-available-aegis-rings-factory-installed?hsLang=en-us) Marathon Electric offers the industry-leading line of **Hazardous Duty™ Division 1 Explosion Proof,...** ### [Five Reasons You Should Use Motors with AEGIS Shaft Grounding Factory-Installed Inside](https://blog.est-aegis.com/five-reasons-for-aegis-inside?hsLang=en-us) **1. Motors run on variable frequency drives (VFDs) need protection against bearing current ** ### [VFD-Ready Electric Motors from Marathon](https://blog.est-aegis.com/marathon-motors-with-bcp?hsLang=en-us) The Marathon® Motors brand began with a single washing machine motor and a simple ambition: To... 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