Genset alignment, longitudinal or transverse?

[Dockhead]

Originally Posted by a64pilot

Alternator ammeter is dead simple, if your ground is internal to the alternator, which it almost certainly is, then you have to install the shunt on the pos. side. If you install on the positive side, then you should have both sense wires fused as they both carry current. Put the fuses at the shunt of course
But it's as simple as installing a shunt in the main wire coming off the alternator and putting the ammeter anywhere you want and connecting the two with two wires.
I bought a Blue Seas ammeter and shunt as my other ammeter and voltmeter were that brand and I wanted them to look the same. I used twisted pair wires to connect the ammeter to the shunt as it's stronger, better protected wire and shielded, but twisted pair is not required, it's just a two wire install, very easy.

My main engine is 27 yrs old, and I think from what I gather here will cost me about 25K to replace it. It is supposedly low hour, but it is old.
My Generator is now about 1 yr old, and the whole thing costs 6K, I feel sure I could get the whole generator without sound shield for 5k and just an engine for much less.

I carry 57 gl of fuel in one tank, fuel burn for me isn't a money thing as much as it's a limited supply thing, I'm trying to establish habits that when one day when fuel isn't as available as it is now, that will serve me well. I hope one day to cruise SoPac. From a money perspective my fuel bill is pretty much irrelevant. I bought ten gallons last weekend which cost me 21 Dollars and I don't remember the last time I bought fuel. 20 bucks every few months just doesn't even matter compared to buying new sails, HF radios and Watermakers etc.

You have the right attitude, but not the right tankage

I carry about 200 gallons of diesel fuel, so purchasing fuel is something which I don't do more than two or three times a year, despite the large number of miles I do every year.

$21 for 10 gallons? Wow, fuel is cheap in the U.S. I have been really happy to pay one euro per liter (tax free in Helgoland), which amounts to more than $4 per U.S. gallon. Otherwise it can cost 1.20 pounds or more, which is about $8 per U.S. gallon.

[a64pilot]

The bottom has dropped out of fuel prices in the US, but US fuel price has always been low compared to Europe, I have always assumed the tax was the difference.

Adding tankage would be a huge problem, I have been considering two 50 gl bladders one day for that trip to the Pacific. I'd rather have it and not need it, then the opposite.

[hamburking]

Originally Posted by senormechanico

Roll, heck. What about pitching?
If you had a multi, roll would be less...

Maybe it could be gimbaled?

[barnakiel]

I have seen more gensets mounted longitudinally. Some mounted across.

This may have to do with space limits on most boats.

b.

[colemj]

Listen to the people who are advocating service access and ease over those who advocate being able to sail at a heel with it running. Gensets are relatively high maintenance things and you will curse yourself if you intentionally mount it so that service is more difficult. Particularly if you mount it so that disassembly of any sound shield is onerous. If so, you will never be doing routine checks of it, and that will make the service needs even greater.

In the most spacious areas, servicing gensets is still a pain. And you will be servicing it more than you expect.

Mount it whichever way it is easiest to disassemble and service. If that means that you can't run it when the boat has a bone in her teeth, so be it.

Mark

[a64pilot]

Think maybe if he can mount it either direction, that he must have plenty of room? I agree mount it where it can be serviced, that's sort of common sense, but I wouldn't mount it in a manner that would contribute to possible oil starvation, that can wipe out bearings pretty quick.
If I remember mine said 20 degrees, but didn't specify an orientation? I would have never thought about gyroscopic forces, that wipes out aerobatic aircraft engines, but they have a long prop and do some significant throwing around.
See I thought since he was worried about gyroscopic forces, he was intending to run the thing underway, I hope gyroscopic forces at anchor aren't an issue?


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[kish]

Originally Posted by Dockhead

I would love to see your ammeter installation on your alternator, because I want to do the same thing. Maybe I can copy some of your ideas. Pix? Description?

Your 2.5 kW alternator puts out some 200 Amps if it is a 12 volt unit or some 100 Amps if it is 24 volt.
A shunt on the alternator output, preferably at the location where it connects to the DC panel busbar could be used to measure alternator current,
but the necessity of making reliable low resistance electrical connections on heavy cable, probably 35 sq. mm cross sectional area is paramount. Think welding cable size.
The voltage drop across the shunt is directly proportional to the current flowing, hence the need for perfectly made connections on the shunt, so that the voltage drop measured reflects only the current flowing and not a component due to resistance at bad connectors.

A better more convenient solution would be to purchase a grip ammeter that can measure DC current. Most commonly available grip ammeters only measure AC currents, but units that measure DC current are also available at a higher price.

Of course such a unit, not being permanently installed would not measure alternator output continuously, but could be used for troubleshooting.

[Pelagic]

Wise words Mark (especially as they agree with my own)

Have had continuous operating Gens mounted both ways on large sailing Super yachts (+60m) and service ergonomics was always the priority.

Scavenging lube oil from Marine Gens sump was not so much the concern as back pressure if exhaust outlet was on Lee side, so engineer preferred to switch to high side Gen.

[sy_gilana]

Our Gen is mounted transverse for service reasons. The only thing thats hard to get at is the starter motor. The Onans (of that era MDJE) have large thrust bearings for heel angle. We never heel more than 12 degrees anyway, she is faster if we reduce sail. Our previous Onan did over 20k hours, and the present one is on 7377 hours right now.
On another note, when we bought Gilana, she had two generators. One was double belt driven on the main engine, with an electric clutch-pulley. An AC gen is a relatively cheap device compared to a DC alternator. Unfortunately the engine needs to run at a fixed RPM and therefore a Hundested Controllable Pitch prop was fitted. Yes I know its crazy, but Lloyds 100/A-1 did not allow gas cooking, so the whole galley was electric.
If you want Aircon while motoring, consider the AC gen option as opposed to DC->Bat->Invert as it is more efficient.
We have removed the AC alternator and now use the clutch to drive a massive bilge pump (2.5" pipes) sucking from a manifold ported to every watertight compartment.
You can get a 5Kw 120/240v 60hz Generator Head for $399.00

[colemj]

Originally Posted by a64pilot

Think maybe if he can mount it either direction, that he must have plenty of room?

I wouldn't assume that. The locker ours is located in allows it to be mounted in either direction, but one of those directions presents the service stuff in a difficult to access place and makes the sound shield difficult to open for routine checks.

I hope gyroscopic forces at anchor aren't an issue?

You should hope so, but we have had some nights at anchor that were much worse than that of the passage getting there!

Mark

[a64pilot]

I don't have a lot of experience anchoring yet, and have only had one bad night, and that was due to my stupidity, although I'll blame the CBP for it by delaying me for the better part of an hour.

Oil starvation at least on my Yanmar main has me puzzled a little, I got knocked down one night last Summer again due to stupidity and during the melee started the engine and it's low oil pressure warning never sounded, but we were laid way over for quite a while, I have no idea of heel angle, but it was way over 20 degrees, so at least for short periods it can take a lot of heel. Eventhough it felt like we were knocked completely down, I'm sure we weren't, never lost steerage for example, I'd guess we were between 45 and 60 degrees?

I had never even thought about gyroscopic forces eating an engine on a boats bearings out, but can see it possibly being an issue on a direct drive generator as the generator does have a lot of mass. Got me thinking though, but a belt drive generator like a Nexgen ought to be immune to gyroscopic forces?

[senormechanico]

Originally Posted by a64pilot

I hope gyroscopic forces at anchor aren't an issue?

It might actually be an advantage. Preventing sailing at anchor?

[a64pilot]

Hey, if we can get a big enough Gyro, not only could we prevent sailing at anchor, but probably eliminate roll as well , guess that might take two gyros though.