In theory....the stator of the motor is grounded via a wire in motor junction box going to an earth ground. This is designed to handle short circuit current to ground. There should be fuses/overloads that also protect the stator
The AGEIS shaft grounding ring is not connected to the stator, just the motor shaft. This is designed to dissipate any voltage/current induced into the motor rotor while in operation. It is my opinion....that this style of grounding ring is not designed for dirty environments, have seen rust/grease/dirt cause the carbon fingers not to make contact.
The likely hood of any electrical issues due to a grounding ring will improve bearing life, not create an electrical issue.
Other option for grounding rings design https://dpa-solvere.com/produc...erview-brochure.html
Dave