As you are most likely aware, grounding of electrical circuits is a matter of safety. The old adage “You can never be too safe!” has always proven to be true. As a manufacturer, Yamaha wants you to be as safe as possible when using their electrical generator and so they ask that you please ground the portable generator when in use.
You ask about a ground rod being included with the generator. I’m sure you will find no manufacturer including one with their generator and we do not provide them with the new Yamaha generator.
Most people do not realize that a grounding rod is intended primarily for a direct lighting strike.
Now the last issue you are concerned with is if you should purchase one. This is an interesting question because properly installed grounding rods are up to 6 feet in length and driven into the earth. That makes it a challenge for use on a “portable generator”. For instance, if someone was on a vacation trip and camping cross country, they would have a terrible pounding a ground rod into the ground and an even worse time pulling the rod back out every time they moved on to the next camping site! As a Yamaha dealer we always suggest that you follow the Yamaha generator owner’s manual since they are the experts for their product. But, what if the user needed to constantly move the generator as described above? You will find that this is the only question on this forum that we cannot answer for you. Every owner of a generator needs to do their own research into this question and, based on how they are using the generator, determine how, OR EVEN IF, they should ground the generator. For instance, if you Google these search words
“portable generator ground rod electrical code”
a wealth of information can be found. At the time that I did it, this OSHA* document was the top result and was entitled:
”Grounding Requirements for Portable Generators.”
One of the most interesting comments made in that article is that grounding a generator could actually be more dangerous in some instances. Please read this article and the other one right below in the search. Very enlightening…
I feel this is a very serious matter that needs an explanation from Yamaha about the reason behind the statement in the owner’s manual. So I have been in contact with Yamaha-US about his issue and they decided to revisit this requirement from the manual and when we receive a reply from them I will be sure to add it to this post.
*U.S. Department of Labor
For more complete information: