Question: I am curious if a standard portable construction-type generator could be used safely on a pontoon-style houseboat by grounding the generator to the hull. Would there be a difference between that and a built-in generator? Are there any other safety considerations here?
Answer: Glad you asked! The short answer is that the use of portable generators of any make or model on boats is not recommended, since they can potentially be quite dangerous. I found it interesting to note that when looking over the Honda Power Equipment website I couldn’t find any reference to marine applications for their product line. Good on them! That said, I’ve seen these and other portable generators for sale at many boat shows.
The ABYC really discourages the use of these generators in on-board applications for two very important reasons. The first reason is electrical. The ABYC requires that for 120-volt AC systems, the neutral conductor and grounding conductor be joined at the source of power (the generator in this case) so that in the event of an electrical short circuit at an appliance, the fault current will get carried directly back to the power source and trip a breaker. Portable generators often keep the neutral and grounding conductors isolated from one another on the device. This is internal to the unit and not easily modified.
The second reason to discourage use of portable generators on boats is the high risk of carbon monoxide poisoning. Most of these units run on gasoline, and the generators often get mounted in locations that can trap exhaust gas and create a deadly situation for the people on board.
The bottom line? Don’t do it!