Do you need a generator grounding rod?
No you don't. And don't confuse grounding with bonding...
Did Santa bring you a new generator for Christmas?
Dear Mike,
Santa brought me an inverter generator and I can’t wait to use it this spring. But the manual says I should drive a ground rod and connect it to the frame of generator. I’ve looked everywhere and keep getting conflicting information on the Internet about generator grounding. What do you know? Samuel
Dear Samuel,
I’ve covered this many times before, but don’t feel bad about your question because even electricians and some generator manufacturers don’t seem to understand how it works for RV power. So here’s the quick answer and a video how to check your generator for a floating neutral.
First off, the big answer is NO. You DO NOT need to drive in any kind of ground rod for any single RV powered from either a portable or onboard generator. While it’s true that you would need a grounding rod if you had a large generator that could power several RVs connected to it at the same time, you simply don’t need one for your situation. What you have created with a single RV running from a generator is something called a local ground plane, which means your entire RV and tow vehicle is its own isolated ground, and doesn’t need to be connected to the earth to be safe.
But my Surge Protector says there’s no ground
But what about when you plug your EMS/TEP (Total Electrical Protection) surge protector into an inverter generator and it shows a “ground” code or error.
Well, what that really means is that you have a floating neutral generator, which doesn’t have anything to do with being “grounded” to the earth at all. The generator (or pedestal) needs to provide power with the neutral and ground wires at nearly the same voltage (not floating). This open ground report is dangerous when plugged into a pedestal outlet, but not when plugged into a portable generator. But the EMS Surge Protector doesn’t know the difference and shuts off the power.
Your generator needs to be bonded, not grounded…
If you get that no-ground error from a surge protector when plugged into a portable generator, all you need to do is get a simple Neutral/Ground Bonding plug I invented more than a decade ago.
Looks like a 15-amp plug without a wire, and it provides an internal jumper between the neutral and ground screws to create a local neutral bonding point. Just plug it into any unused 15- or 20-amp outlet on the generator (NOT in the RV) and you’re good to go. You can purchase a generator bonding plug from Amazon.Yes, it’s the one I designed, but never bothered to patent.
Here’s how to test a generator for a floating neutral
You don’t need a grounding rod on your RV or generator
Finally, NEVER drive any grounding rod in the earth without getting a proper inspection from your local Miss Utility (call before you dig – 811). Remember, there are all kinds of buried water pipes and electrical wires at any campground, and many homes also have buried natural gas pipes. You don’t want to punch through any of those pipes with an 8-ft grounding rod. The results can be a deadly shock or explosion. So you don’t need a ground rod, and you’re not allowed to drive one anyway. Make sense?
Let’s play safe out there… Mike
Hi Mike. Some very good info here. I Bought an inverter generator and safety manual is indicating it should be grounded. I want to install a standalone circuit with 2/3 13A amp sockets so that I have power points in the house during an outage. Not going to connect with existing panel. Effectively a built in extension lead with a 16A IP rated socket outside. Do I need to ground my generator? Can I connect to existing grounding rod for main system? Manual also states “There is a permanent conductor between the generator (stator winding) and the frame. The statue winding is isolated from the frame and from the ac receptacle ground pin. Electrical devices that require a grounded receptacle pin connection will not function if the receptacle ground pin is not functional.
I have a 7500 watt open frame gen that I use as a backup for my house power (all properly wired with a transfer switch, etc). The owners manual says to ground it. I’ve run a cable from the gen to the existing house ground rod. Is this OK?