--- title: Explosion Proof Motors Available with AEGIS Shaft Grounding Rings description: Explosion proof motors on variable frequency drives need bearing protection. Only AEGIS rings satisfy UL & ATEX Directives for hazardous locations. image: https://blog.est-aegis.com/hubfs/Imported_Blog_Media/xri-aeg-300x206.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) # Explosion Proof Motors Available with AEGIS Shaft Grounding Rings [Home](https://www.est-aegis.com/) » [Blog](https://blog.est-aegis.com/) » Explosion Proof Motors Available with AEGIS Shaft Grounding Rings [AEGIS](https://blog.est-aegis.com/author/estaegis) Jun 18, 2019 Not just any off-the-shelf motor can safely run in a potentially explosive atmosphere.  Explosion proof motors need to be able to contain any sparks or small explosions that might occur within themselves, and prevent them from getting out and igniting a larger explosion.  Motor manufacturers have put thousands of hours into designing these motors to be as safe as possible. There is an additional design challenge for explosion proof motors that will be run by VFDs.  These motors need shaft grounding to prevent electrical bearing damage from the drive.  Shaft grounding devices are currently considered to be sparking devices.  This means that they can't be installed outside the motor, in a highly flammable atmosphere.  And internal installation has its own challenges.  A carbon shaft grounding brush can't be used because it wears.  This means the brush must periodically be adjusted or replaced.![xri-aeg](https://blog.est-aegis.com/hs-fs/hubfs/Imported_Blog_Media/xri-aeg.jpg?width=305&height=209&name=xri-aeg.jpg) The UL®-accepted solution is to install an [AEGIS® Shaft Grounding Ring](https://www.est-aegis.com/product/sgr/) inside the motor, outside of the flame path.  Unlike carbon brushes, an AEGIS ring typically lasts for the lifetime of the motor.  AEGIS rings can be installed according to the UL procedures by a number of motor repair companies. Motor manufacturers can also follow the approved procedures for shaft grounding.  In the US, Marathon Motors offers stock explosion proof motors with AEGIS rings factory-installed.  And ABB/Baldor offers custom builds of XP motors with AEGIS. Marathon Motors offers Blue Chip® Hazardous Duty™ NEMA Premium® XRI® motors with AEGIS installed.  Models with AEGIS rings have catalog numbers that end "-P". In Europe, WEG Electric offers optional AEGIS rings inside the W22Xd line of flameproof motors.  These motors comply with the ATEX Directives. To learn more about AEGIS shaft grounding and best practices for electrical bearing protection, [sign up for a training](https://www.est-aegis.com/resources/training/). We offer monthly live training webinars, and we can also visit your facility to review your exact application. 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An... ### [Protecting VFD-driven Motors in Plastics Production](https://blog.est-aegis.com/protecting-vfd-driven-motors-in-plastics-production?hsLang=en-us) Today, there are hundreds of types and blends of plastics, and they can be formed, molded,... ### [How To: Bearing Protection Handbook Details Best Practices For Motor Protection and Repair](https://blog.est-aegis.com/how-to-bearing-protection-handbook-details-best-practices-for-motor-repairs?hsLang=en-us) This 56-page technical handbook describes best practices for protecting motor bearings from... 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