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Old 16-10-2014, 14:27   #46
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Re: How Do You Use Your Generator?

40 hrs. is quite an amount of time. A ltr. in that time doesn't sound that bad. It may come back with usage. Ring may seat, valve guides? Don't jump the gun on spending a bunch on it. Just use it and keep a log of oil consumption.
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Old 16-10-2014, 19:32   #47
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Re: How Do You Use Your Generator?

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Originally Posted by FlyingCloud1937 View Post
A wet stacked engine, glazes the bores which allows oil past the rings. The heated oil polymerizes in the bores cross hatching.
A wet stacked engine, carbons up the ring lands which allows oil past the rings.

Ruining Hard can help burn the carbon out of both places, it can even help de-glaze the bores somewhat.

The MM/ATF trick can/will internally desolve the carbon, and even help de-glaze the polymerized bores.

If it were the valve guides, it would stop smoking after warm up typically.

Lloyd
This actually explains a lot, and makes me think that running it loaded up is likely the best starting point. As I think I mentioned, it seems to improve when I'm out on passage or at anchor and thus using the generator a lot. This probably also explains why my propulsion engine hasn't exhibited similar symptoms. Unlike the generator, the main engine is easy to load up and I definitely haven't babied it.

It also dawned on me how under-utilized my generator has been. I had forgotten that the PO had a watermaker installed which he subsequently removed. With a watermaker, two a/c units, water htr., refrig/freezer, batt. charger, TV/radio, microwave, & numerous AC outlets throughout the boat, this probably explains the rather large capacity 8kw genset. Because both a/c units & the water htr. share the same 30A circuit, I'll have to move one of the a/c units to the other 30A circuit to get an adequately high load on the generator. The start-up amperage draw on these old a/c units always makes me a bit nervous. Still, a full load would require running each circuit to its max (30A) capacity.

Dan
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Old 16-10-2014, 19:38   #48
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Re: How Do You Use Your Generator?

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40 hrs. is quite an amount of time. A ltr. in that time doesn't sound that bad. It may come back with usage. Ring may seat, valve guides? Don't jump the gun on spending a bunch on it. Just use it and keep a log of oil consumption.
That's been the plan, and there's a fair chance it will come back. For awhile there, I was starting to feel sorry for anybody anchored downwind from me, but it probably was never as bad as I thought it was. Definitely good advice to start keeping better track of how much oil I am adding b'twn my regular 100 hr. changes. I don't like to let it get too far towards the bottom of the dipstick so I could be over-estimating how much I'm actually adding.

Thanks!

Dan
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Old 16-10-2014, 23:51   #49
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Re: How Do You Use Your Generator?

So you must be a cook...

french de-glaze=white wine and brown bits.

creole de-glaze=cold water in a hot cast iron .

both=de-polymerization.

A diesel mechanic=water injection into the intake.

I couldn't begin to to tell you how, without being on-site.

But, I can tell you that it's all the same.

some chef's know how to do it.

Lloyd

Quote:
Originally Posted by Exile View Post
This actually explains a lot, and makes me think that running it loaded up is likely the best starting point. As I think I mentioned, it seems to improve when I'm out on passage or at anchor and thus using the generator a lot. This probably also explains why my propulsion engine hasn't exhibited similar symptoms. Unlike the generator, the main engine is easy to load up and I definitely haven't babied it.

It also dawned on me how under-utilized my generator has been. I had forgotten that the PO had a watermaker installed which he subsequently removed. With a watermaker, two a/c units, water htr., refrig/freezer, batt. charger, TV/radio, microwave, & numerous AC outlets throughout the boat, this probably explains the rather large capacity 8kw genset. Because both a/c units & the water htr. share the same 30A circuit, I'll have to move one of the a/c units to the other 30A circuit to get an adequately high load on the generator. The start-up amperage draw on these old a/c units always makes me a bit nervous. Still, a full load would require running each circuit to its max (30A) capacity.

Dan
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Old 17-10-2014, 06:23   #50
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Re: How Do You Use Your Generator?

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Originally Posted by FlyingCloud1937 View Post
So you must be a cook...

french de-glaze=white wine and brown bits.

creole de-glaze=cold water in a hot cast iron .

both=de-polymerization.

A diesel mechanic=water injection into the intake.

I couldn't begin to to tell you how, without being on-site.

But, I can tell you that it's all the same.

some chef's know how to do it.

Lloyd
Just when I thought trying to be a diesel mechanic was tough . . . .
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Old 17-10-2014, 06:55   #51
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Re: How Do You Use Your Generator?

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Originally Posted by FlyingCloud1937 View Post
I have a simple black box, it is comprised of a watt hr meter, and an hr meter. I hook it up to the gen out, and the op switch.

After a month installed on customer boat, on average. I find that the watt hrs produced, against time, and rated Generator. That the system is running about 20-35% of load capacity.

Under-running a gen causes wet stacking, which fouls the bores, rings, and valve seats, and worst of all carbons up the injector tips. This leads to fuel fouled lube oil.

If your are going to run an A/C gen run it in batch mode, use an inverter for incidental loads.

Now back to the OP....NEVER RUN IT WITH OUT SEAWATER...don't forget to open the seacok...hhehe

Lloyd




[/I]
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Concerning "wet stacking" --

I wonder what load is needed on a genset to be sure to prevent this.

I think many people don't realize that gensets are much more sensitive to this than propulsion engines, because they run at a constant speed. That means that if you take the electrical load off a genset, the % load at that RPM will be much lower than if you take the load off your main engine and let it idle. So it's much more dangerous on a genset. I think the danger is much exaggerated regarding main engines on sailboats and that wet stacking is almost impossible. But with gensets, no load leaves the engine running at 1800, or much worse, 3600 RPM, pumping air through it, cooling off the bores, and this can indeed mean big trouble. I think the horror stories we hear about gensets and bore polishing are more or less all caused by this scenario: People leave them on all the time to run air conditioning. Then they go to sleep, it cools off outside, the A/C starts to run a very low duty cycle, and the genset is running without a load most of the time, all night long. A few months of this and they go kaput.

But I think outside of that situation, nothing like a 75% load is needed to keep the genset happy. I think any moderate load ought to be enough. I follow the rule that my 6.5kW, 1500 RPM set needs at least 1kW of load, and I avoid running it at less than that. I do "batch process" (in Lloyd's phrase) electrical jobs and so often have a 75% load on (but I never put on more than 90%, and try to avoid more than 80%). It's more efficient anyway because there is a certain fixed overhead of fuel consumption, so fuel consumption per kW/h of power produced goes down a lot over 25% load.

I have come to love and respect my genset more and more over the years. I don't think it's as good as a Northern Lights, but it has performed really well for me, giving me zero trouble in 5 years and 1200 hours not caused by my own stupidity. It burns zero oil between changes, produces cleaner power than I have at home, and the 3-cylinder 1000cc Yanmar prime mover purrs like a kitten. Since I live on board much of the year without shore power, I really rely on it -- it's a fundamental system for me.

Now if I could only stop starting it with the sea cock closed
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Old 17-10-2014, 07:25   #52
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Re: How Do You Use Your Generator?

More great info Dockhead -- thanks. My learning has thus far been devoted more towards the propulsion motor, and I wish I knew more beyond basic maintenance on my genset.

Do you or others have a Hertz meter, and does it typically show a lower frequency output as you apply loads? A prior post indicated this may be symptomatic of a poorly performing governor. I have to confess that I don't actually know if mine has a mechanical or electronic one! I suppose the danger may be more to the appliances it's powering than the genset itself. In any event, I have a 60Hz unit and it will typically drop to 56-57 as I turn on a/c units, heaters, etc. Is this something unusual that I should pursue??
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Old 17-10-2014, 07:40   #53
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Re: How Do You Use Your Generator?

I have a Fisher Panda mini 8 according to the manual on board my yacht. When we are on the anchor I find I only use it when we stay at the same place for a couple of nights to run the hot water heater about 45 minutes . We have enough solar power to charge the battery bank so it doesn't get a lot of use. It says in the manual if using I think it's 75% of the power to turn things off for 5 minutes before switching it off. When at the marina I usually run it every week or two to make sure it still runs. Should I use it more than that?Click image for larger version

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Old 17-10-2014, 07:56   #54
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Re: How Do You Use Your Generator?

Usually, we just crank ours (Northern Lights 4.5 kw) to run the A/C. But, I admit I have cranked it a few times, just to microwave something for lunch.

I agree it's not a bad idea to run the AC every time you crank them just to keep a good load on them, so we just leave the AC on and it goes on as soon as the genset cranks.

Ours has over 7000 hours, and still seems as good as new (we only have 2700 hours on the main engine).
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Old 17-10-2014, 08:05   #55
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Re: How Do You Use Your Generator?

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More great info Dockhead -- thanks. My learning has thus far been devoted more towards the propulsion motor, and I wish I knew more beyond basic maintenance on my genset.

Do you or others have a Hertz meter, and does it typically show a lower frequency output as you apply loads? A prior post indicated this may be symptomatic of a poorly performing governor. I have to confess that I don't actually know if mine has a mechanical or electronic one! I suppose the danger may be more to the appliances it's powering than the genset itself. In any event, I have a 60Hz unit and it will typically drop to 56-57 as I turn on a/c units, heaters, etc. Is this something unusual that I should pursue??
Don't look for problems.
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Old 17-10-2014, 08:52   #56
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Re: How Do You Use Your Generator?

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I have a Fisher Panda mini 8 according to the manual on board my yacht. When we are on the anchor I find I only use it when we stay at the same place for a couple of nights to run the hot water heater about 45 minutes . We have enough solar power to charge the battery bank so it doesn't get a lot of use. It says in the manual if using I think it's 75% of the power to turn things off for 5 minutes before switching it off. When at the marina I usually run it every week or two to make sure it still runs. Should I use it more than that?Attachment 89859
Every couple of weeks should be fine. You should put a decent load on it and let it go for an hour, I would say.

I have a 16kW standby generator at my lake house which I've never used in anger (probably should sell it). The caretaker runs it once a month under load for two hours. It runs fine after 12 years of that regime.
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Old 17-10-2014, 08:55   #57
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Re: How Do You Use Your Generator?

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Originally Posted by Exile View Post
Do you or others have a Hertz meter, and does it typically show a lower frequency output as you apply loads? A prior post indicated this may be symptomatic of a poorly performing governor. I have to confess that I don't actually know if mine has a mechanical or electronic one! I suppose the danger may be more to the appliances it's powering than the genset itself. In any event, I have a 60Hz unit and it will typically drop to 56-57 as I turn on a/c units, heaters, etc. Is this something unusual that I should pursue??
As the previous poster said, don't look for problems. A brief sag like that shouldn't hurt anything.

Your governor is in all likelihood a mechanical one. These are simple, reliable devices which rarely give problems.
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Old 17-10-2014, 09:44   #58
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Re: How Do You Use Your Generator?

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As the previous poster said, don't look for problems. A brief sag like that shouldn't hurt anything.

Your governor is in all likelihood a mechanical one. These are simple, reliable devices which rarely give problems.
Yep, and if they have any problem it generally causes engine swelling. All he is seeing is a slight delay in compensating RPM for a sudden load. A couple of cycles isn't going to hurt a thing, especially a sort time.
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Old 17-10-2014, 10:43   #59
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Re: How Do You Use Your Generator?

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Yep, and if they have any problem it generally causes engine swelling. All he is seeing is a slight delay in compensating RPM for a sudden load. A couple of cycles isn't going to hurt a thing, especially a sort time.
Indeed. And it's a normal, unavoidable phenomenon on alternators where the frequency is determined by the rotor speed. Because it's impossible to regulate the speed of the engine with 0.0 response time -- the engine itself needs a certain amount of time to respond to the throttle input, even if the governor's response were instantaneous.
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Old 17-10-2014, 11:13   #60
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Re: How Do You Use Your Generator?

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Indeed. And it's a normal, unavoidable phenomenon on alternators where the frequency is determined by the rotor speed. Because it's impossible to regulate the speed of the engine with 0.0 response time -- the engine itself needs a certain amount of time to respond to the throttle input, even if the governor's response were instantaneous.
Been on English destroyers using our 60hz machines. Worked well on 50Hz, I still like cps vs. Hz. The best part was the dynamite ale/beer onboard.
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