Running Generator While Under Way

[BandB]

Same here. It is important to adequately load your generator. Depending on your electrical demands relative to the output of your alternators, you may be better off running the genny only after the batteries have run down a bit.

Let's be careful too to know what adequate loading is. I've heard all these stories about never loading under 50%. Northern Lights, however, states the following: "A generator should never run with less than a 25% load. 35% to 70% is optimal." One needs to check their owners manual and/or with the manufacturer. And don't go to a field representative at a boat show or elsewhere. Get the official recommendation.

 

[Hawgwash]

Yes, they produce good heat all winter.

Thank you. Always wondered and you are the first I have thought to ask. Should have asked, what size unit(s) do you have?

 

[drb1025]

Thank you. Always wondered and you are the first I have thought to ask. Should have asked, what size unit(s) do you have?

I have three marine air units, two 16k btu and a 12k btu.

 

[Hawgwash]

I have three marine air units, two 16k btu and a 12k btu.

Thanks.

 

[Bay Pelican]

You guys must have huge electrical draws if your engine's alternator isn't sufficient when underway, necessitating simultaneous use of the genset.

Two radars, autopilot, computer, monitor and all sorts of lights after pulling up 150 feet of chain knocks the heck out of the standard alternator (75 amp) on a single engine running at 1600 rpm. Not that it isn't charging but it is charging slowly and I prefer a full charge when I anchor the next morning.

 

[O C Diver]

Does your reverse cycle produce adequate heat here on the coast for winter cruising?

I have 3 Webasto heat pumps on my boat. They worked down to about 35 degrees. The efficiency of the units drops as the water temperature drops. Below 35 degrees in brackish water, there needs to be more water flow through the condenser as the refrigeration effect starts to generate ice inside the condenser. I'm running 3 units off one water pump. If I planned to use them below 40 degrees, each unit would have it's own water pump.

Ted

 

[FF]

I always figure the all up cost of a noisemaker is about $10. per hour.

Purchase , install, feed, maintain, repair and eventually replace.

A Good rebuilt DN 50 alt with a 4KW sine wave inverter might cost 5 boat bucks to get operational, but would save big if the boat main engine were used much.

4KW will start 2 normal boat air cond.

OF course the best saving would be to put HYD pump on the main engine and a 6KW power head,,, is half the cost of the big buck inverter.

 

[HiDHo]

"4 KW will start 2 normal boat air cons". Have to be very small units, our 5 KW NL runs two 16,000 BTU units with the help of a "Smart Start". Two units start amps if they start at the same time can trip your breakers.

 

[Phil Fill]

Since we are dock queens and do not leave the dock often, we leave the gen set run. We also have a cruise gen powered by the main engine that we switch to for longer cruises. So we have a generator running from the time we leave the dock to we are tied to a dock.

 

[dhays]

Yes, they produce good heat all winter. I was a little concerned about the water temps when I bought the boat, as the units become inefficient and stop working as water temp reaches around 40 degrees, but I have never had an issue. The water here is generally mid-40s in the winter. I was recently talking with a local boater that was getting ready for his fourth Alaska trip and his heat source was also reverse cycle. He said he has never had an issue with heat even in SE Alaska. That surprised me, although I am planning to install a Wallas diesel heater for a supplemental heat source before we make that trip.

That is a great question Hawg asked. Am I to assume that your reverse cycle heater uses raw water for a heat sink/source as opposed to air? I was on a newish boat the other day that had a reverse cycle (heat pump essentially) that used air as the heat sink/source. I know they would not serve my purposes, but a system that used raw water would work pretty well most of the time. I can get ice in my harbor during really cold spells (fresh water streams feed into the harbor near my moorage) but most places the water temps stay in the high 40s in the winter.

 

[Hawgwash]

I can get ice in my harbor during really cold spells (fresh water streams feed into the harbor near my moorage) but most places the water temps stay in the high 40s in the winter.

Not a lot of difference between Seattle and Ketchikan.

https://www.nodc.noaa.gov/dsdt/cwtg/npac_tmap.htmlKetchikan AK

Ketchikan Recent Water Temperature:
44.8°F (7.1°C)
Observation Date and Time:
Fri, 26 Feb 2016 16:42:00 GMT

February Monthly Mean Temperature:
43°F (6.1°C)

Station Information

Seattle Recent Water Temperature:
48.6°F (9.2°C)
Observation Date and Time:
Fri, 26 Feb 2016 16:48:00 GMT

February Monthly Mean Temperature:
46°F (7.8°C)

Station Information

 

[dhays]

Yup, and in the summer it will get just above 50 degrees F

 

[kulas44]

A well maintained 12 kw diesel gen at 1800 rpms may only last 10,000 hours if ran at no load. It "may" run 20,000 hours at continuous half load. Or the same at full load. No one here is gonna wear one out in any case. Lack of use kills most of them.

 

[drb1025]

That is a great question Hawg asked. Am I to assume that your reverse cycle heater uses raw water for a heat sink/source as opposed to air? I was on a newish boat the other day that had a reverse cycle (heat pump essentially) that used air as the heat sink/source. I know they would not serve my purposes, but a system that used raw water would work pretty well most of the time. I can get ice in my harbor during really cold spells (fresh water streams feed into the harbor near my moorage) but most places the water temps stay in the high 40s in the winter.

Yes, the reverse cycle takes heat from the raw water.