By Mike Sokol
Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM.
Under your RV Electricity, RV generators, I could not find any mention of the issue of a portable generator not powering an RV. My 2000-watt Honda generator simply doesn’t power my RV at all. I have been told that I need to make a short extension cord with the neutral and ground strapped together because of something like the RV becomes a subpanel or something. Can you address this situation. —Timothy Shively
I have indeed written about this problem many times recently, but I have published so many articles (literally hundreds of them) over the years, that it can be difficult to find a particular topic. So for 2020 (my 10th anniversary of writing for the RV industry), I’m spending hundreds of hours gathering all of my educational material into one place on RVelectricity.com. As you can imagine, this will take months of work to complete.
But in the meantime, here are the basics of what’s happening with your Honda 2000 inverter generator, and a quick fix that will cost you around $10 to correct.
Many portable generators (and most inverter generators) have something called a floating neutral. That is, the neutral and ground wires inside of the generator are isolated from each other. So if you were to put a digital meter on the generator outlet, instead of reading 120 volts from ground to hot and around 0 volts from ground to neutral like you’ll find in a home or campground electrical outlet, you may read something like 60 volts between the hot and ground, and 60 volts between the neutral and ground.
That confuses EMS Surge Protectors since they think that the outlet you’ve plugged into has lost its ground, which could create a dangerous hot-skin contact voltage if you’re plugged into a pedestal, but which is perfectly safe being plugged into a generator that’s completely isolated from earth ground.
What to do, and do safely? Well, nearly 10 years ago I saw this problem and came up with a very simple solution that creates something called a neutral/ground bond in your portable generator, which is exactly how all installed RV generators, as well as pedestals and home outlets, are wired. To watch the video on how to test your generator for a floating neutral, click HERE.
All you need is a G-N 15-amp bonding plug that I designed, and plug it into any spare 15/20-amp outlet on your portable inverter generator. Then plug your RV’s shore power cord into the other generator outlet. This creates the proper 0 volt difference between the neutral and ground in the generator, allowing your EMS to operate properly. You can get a G-N bonding plug already wired from Southwire (and others) for $10 to $15, and just plug it into your generator (NEVER an outlet inside of your RV) to “neutral bond” it. You can buy a generator neutral bonding plug on Amazon HERE (paid link).
Here’s a more detailed article on how this works. I published this one just a few months ago but it’s difficult to find unless you know the proper key words to search for. Read it HERE.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
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