Overnight Cooling Without Shore Power

[skipmac]

Originally Posted by flyingnut40

Has ANYONE noticed that the OP has not commented since post #1?

I did notice, but also see that she has logged into the forum as recently as last week. So she may be reading all the comments with great interest............. or not.

[valhalla360]

Originally Posted by flyingnut40

Has ANYONE noticed that the OP has not commented since post #1?

Yeah, that's why my comment tried to elicit more info about what she was proposing.

She may have some magical perpetual motion machine or it may be a simple solar/battery/inverter system with a small air/con...All this discussion may have nothing to do with her idea.

[witzgall]

I posted more as an FYI, some here may find it interesting.

Yanmar has always published low PTO numbers for their engines. Many of us know owners that have safely exceeded those values for many years without issues. However, nobody is going to tell you it is just fine to exceed them.

We work with a well-known catamaran builder that installs 2nd alternators @24v on their boats. Yanmar limits these to 70a. Many would love for them to loosen up these restrictions a bit.

Volvo offers kits to add second alternators to many of their engines, up to 170a at 24v. These brackets are for J-180 mount alternators, so the 96 series 60a would most likely be ok with them.

It will be interesting to see if 48v takes off in the marine marketplace. The acceptance many end up being regional - like 24v in europe is now. One of our Australian dealers said that 48v is taking off there.

Chris

Originally Posted by Dockhead

That sounds great, but either of those would greatly exceed the maximum permitted power take off from the front of my 100hp Yanmar. So I'm not quite sure how any of us would drive one of those.

[a64pilot]

Couple of decades ago I believe it was we were supposed to go to 42V in automobiles.
In theory there are significant advantages, but it never happened, I believe mostly because every system would need new parts, every light bulb, everything, and it just didn’t happen.
https://en.wikipedia.org/wiki/42-volt_electrical_system

Now when we see 48V anchor and running lights being same priced as 12V and common to say nothing of radios, autopilots, inverters and everything else, sure it could happen.
It will make battery banks more complex and expensive, you need as a min 8 6V batteries all in series, and if you want go bigger, it’s going to take 16 6V batteries. Half that number for 12V of course.
Nothing in between will work though it’s multiples of 8, or 4 for 12V.
I wouldn’t expect to see it, even though it’s more efficient and enables smaller wiring etc.
But every electrical device on the boat has to change, starters, sending units, gauges the whole shebang.
If you answer is to install converters to down convert 48 to 12V, then that adds expense, another failure point and removes the advantage of higher voltage.

Now with all electric autos becoming a thing, we have another shot at higher more efficient voltages, let’s see what happens. If 48V autos become common place, then I’d expect to see 48V accessories and that may make it a reality.

[a64pilot]

Now so far as exceeding Yanmar’s published PTO maximum’s, your foolish to do so, for one it’s likely there went your warranty, and if you do your assuming of course that Yanmar Engineer’s are well stupid and publish unrealistic low numbers. Now why would they do that?
Personally I believe that Yanmar has some excellent very experienced Engineers, now the Company may make decisions that I don’t like based on profitability and not build the best motor possible and build the most profitable motor instead, but I sure wouldn’t be intentionally exceeding their published maximums for anything, including RPM or operating temps or PTO.

[OceanPlanet]

Originally Posted by a64pilot

Now so far as exceeding Yanmar’s published PTO maximum’s, your foolish to do so, for one it’s likely there went your warranty, and if you do your assuming of course that Yanmar Engineer’s are well stupid and publish unrealistic low numbers. Now why would they do that?
Personally I believe that Yanmar has some excellent very experienced Engineers, now the Company may make decisions that I don’t like based on profitability and not build the best motor possible and build the most profitable motor instead, but I sure wouldn’t be intentionally exceeding their published maximums for anything, including RPM or operating temps or PTO.

Some builders we work with are switching from Yanmar/Volvo to Beta Marine, who is installing our American Power 24V x 185A HPI alternators without canceling the engine warranty. We send the alternators/regulators to the UK, where they're installed by Beta before shipping the engines to the builders (Taiwan, China, wherever).

And we have plenty of Yanmar/Volvo refit projects where the engines are often out of warranty anyhow. Have been using MGDC or APS (12V or 24V) alternators in the stock position with upgraded pulleys & belts. Not a single crank bearing issue over many years...

Currently Marine Electric Systems in MD is installing an Integrel 48V system on a new Volvo D2, in coordination with Volvo.

So, despite fears, there are a lot of high-power alternators happening out there.

[a64pilot]

No one said there weren’t a lot of high power alternators out there. However in my opinion it’s not really very honest to sell someone something that exceeds the manufacturers limit, and not tell them that, and that’s happening in I believe all cases.
I m not pointing you out, but the industry if you will, I believe when someone sells a 200 amp or other above 100 amp alternator at 12V, meant to fit a Yanmar, half that at 24 of course, there ought to be a warning to check that your not exceeding your engines limit.
Will it kill engines? Who knows, but it does exceed Yanmar’s published limits.
Why do those limits exist? In my opinion it’s the crankshaft front bearing’s limit and exceeding its limit will over time cause wear, that will cause low oil pressure and in extreme cases it could spin a bearing as the tolerances open up enough for it to spin, and then your looking at being stranded and or an expensive repair.

There have been enough threads on here for truly massive alternator installs with the idea of charging LFP banks that I believe you will see engines being damaged.
A lead bank often won’t pull massive amps for very long, and that means that the engines limit isn’t being exceeded for long, but LFP can pull the max for an extended time, depending on SOC of course and bank size.

[OceanPlanet]

Originally Posted by a64pilot

No one said there weren’t a lot of high power alternators out there. However in my opinion it’s not really very honest to sell someone something that exceeds the manufacturers limit, and not tell them that, and that’s happening in I believe all cases.
I m not pointing you out, but the industry if you will, I believe when someone sells a 200 amp or other above 100 amp alternator at 12V, meant to fit a Yanmar, half that at 24 of course, there ought to be a warning to check that your not exceeding your engines limit.
Will it kill engines? Who knows, but it does exceed Yanmar’s published limits.
Why do those limits exist? In my opinion it’s the crankshaft front bearing’s limit and exceeding its limit will over time cause wear, that will cause low oil pressure and in extreme cases it could spin a bearing as the tolerances open up enough for it to spin, and then your looking at being stranded and or an expensive repair.

There have been enough threads on here for truly massive alternator installs with the idea of charging LFP banks that I believe you will see engines being damaged.
A lead bank often won’t pull massive amps for very long, and that means that the engines limit isn’t being exceeded for long, but LFP can pull the max for an extended time, depending on SOC of course and bank size.

Of course we make sure that everyone knows, and it's their decision.

[Dockhead]

Originally Posted by a64pilot

No one said there weren’t a lot of high power alternators out there. However in my opinion it’s not really very honest to sell someone something that exceeds the manufacturers limit, and not tell them that, and that’s happening in I believe all cases.
I m not pointing you out, but the industry if you will, I believe when someone sells a 200 amp or other above 100 amp alternator at 12V, meant to fit a Yanmar, half that at 24 of course, there ought to be a warning to check that your not exceeding your engines limit.
Will it kill engines? Who knows, but it does exceed Yanmar’s published limits.
Why do those limits exist? In my opinion it’s the crankshaft front bearing’s limit and exceeding its limit will over time cause wear, that will cause low oil pressure and in extreme cases it could spin a bearing as the tolerances open up enough for it to spin, and then your looking at being stranded and or an expensive repair.

There have been enough threads on here for truly massive alternator installs with the idea of charging LFP banks that I believe you will see engines being damaged.
A lead bank often won’t pull massive amps for very long, and that means that the engines limit isn’t being exceeded for long, but LFP can pull the max for an extended time, depending on SOC of course and bank size.

Does anyone know whether non-Yanmar boat engines have higher permitted PTO? Is Yanmar really more restrictive than others?

[a64pilot]

Originally Posted by OceanPlanet

Of course we make sure that everyone knows, and it's their decision.

Well that’s good, it means your a first class operation in my opinion, but you may be the only one that does.

[a64pilot]

Originally Posted by Dockhead

Does anyone know whether non-Yanmar boat engines have higher permitted PTO? Is Yanmar really more restrictive than others?

I think you would find that it depends on what the motor was initially designed for, some commercial motors will run a hydraulic pump off the front of the motor as an example, my old JD 410 backhoe did and a backhoe has heavy duty hydraulics of course and would pull a lot of HP.
Pretty safe bet that any motor designed for high PTO loads on the front of the crankshaft will have a larger than normal front bearing, similar to the rear.
I overhauled the JD 410, but don’t remember the front crank bearing, it’s been decades ago.
I assume the only way to answer that is to find installation manuals for Yanmar terrestrial motors, I feel sure that for example a JD lawnmower with a Yanmar engine won’t tell you the PTO limit.

[OceanPlanet]

Originally Posted by Dockhead

Does anyone know whether non-Yanmar boat engines have higher permitted PTO? Is Yanmar really more restrictive than others?

Beta, as mentioned above.

For example, HH50 cats are using the Beta 38's with the 185A x 28V APS HPI's

[a64pilot]

Sorry, I thought you were talking about other Yanmar engines.
Not that I have installed every motor there is, but I’ve honestly not seen a motor list a PTO limit for the front crankshaft, or maybe more accurately just not noticed. I wonder if Beta does as they aren’t an actual manufacturer are they? They marinize Kubota’s?

[OceanPlanet]

Originally Posted by a64pilot

Sorry, I thought you were talking about other Yanmar engines.
Not that I have installed every motor there is, but I’ve honestly not seen a motor list a PTO limit for the front crankshaft, or maybe more accurately just not noticed. I wonder if Beta does as they aren’t an actual manufacturer are they? They marinize Kubota’s?

Beta does test the alts before approval, and do the install themselves. They recently tested and approved the 48V x 8kW Integrel. However it took a good while, so I assume they really wanted to put through the paces before giving the OK.

[RaymondR]

There is a lot of difference in the loading imposed between a hydraulic pump with an inline installation on the front of the engine and an alternator where the extra loading is lateral.

However since LiPo and such batteries will accept high charge rates from large capacity alternators and LiPo is becoming more common, and perhaps even more so if the price reduces, it's probably time for the engine manufacturers to install bearings with higher lateral load capacities on the front of their engines.