Running Generator while underway

[CrewRest II]

We have Maxum 4600 with an 8.0kw Westerbeke generator. We typically operate the generator while static/anchored or when no shore power is available. I hear mixed messages whether it’s ok to run the generator while underway. Has anyone experienced any problems doing so? Especially, since the gen panel is in the salon and we typically are on the flybridge while underway and unable to directly monitor the generator operation. Any suggestions or considerations?

[MoonRiver]

May be a silly question, but why would you need to run the gennie while U/W? Main engines can support electrical demand and or charge battery banks.

[Phillbo]

Make sure the thru hull for the water supply does not come out of the water when under way.

Otherwise I see no issue...

[dbriceno]

I never had an issue running the genny while under way. I needed it to run my A/C, television, ice maker & refrigerator (I replaced mine with a larger stainless 110 version delivered to the boat for $300 from Lowes instead of $1200).

[CrewRest II]

No silly questions... An ounce of prevention is worth a pound of cure. I can’t find anything in the manuals, so I thought I’d ask the question. I would like to run the microwave, ice maker, and TV on long transits. Keeps the grandkids happy! The gen set thru-hull is stbd stern. Shouldn’t be an issue. Thanks for the responses!

[Trey5684]

I have a 3100SE and never had an issue running gen while underway, keeps a/c and other 110 only items running on long cruises. Never saw a warning about not running the gen in manuals. Of course there may be opposing views.

[jparsons121]

No issues with running the gen sets underway.
Most of the larger yachts I’ve run switch over to gen power at the dock prior to leaving to maintain constant 110/220. All depends on what demand for power you have underway.

In the smaller boats, most of the systems are designed around 12v DC or with dual voltage capabilities as we don’t have demand for AC power underway.

[CrewRest II]

Good stuff! Thanks again for the feedback.

[shrew]

Do you have an external pickup strainer? If not, no worries, other than the risk of plugging the intake if you run through grass or patches of seaweed. If so, then it needs to be a running style pickup. If it's the clam shell style with slots on one side and solid on the other, then slots need to be oriented forwards. If installed on a generator, it is frequently installed with the solid side forward which isn't designed to be used while running.

[CrewRest II]

Shrew, Good question... I don't recall the pickup strainer type I have when I had the boat hauled-out for the survey. Took a bunch of pics, but nothing as exciting as the pickup strainer. However, I will be hauling it out this month to repaint the hull, so I will take note and orient as you suggest. Thank you for the tip!

[jparsons121]

Shrew makes a good point. On powerboats the use the pickup for cooling the mains while underway, forward facing is the typical installation. On sailboats or pickups for he sets that may not be in use, slots aft are the norm to keep the pickup from ramming water up thru the pickup and potentially flooding the engine thru the exhaust.

If you have appropriate seacocks and religiously use them, this point would be moot.

[shrew]

Originally Posted by jparsons121

If you have appropriate seacocks and religiously use them, this point would be moot.

Not completely moot.

If there is a clamshell style pickup, and it's mounted backwards, it doesn't work well while running and should be turned around to the running position if the intention is to run the generator while underway. If turned around into the running position, then the seacock will absolutely need to be closed if you intend to run with the generator off.

[mrt214]

That is why gensets were installed, so you can power the a/c and all 110 items on the boat.