Super quiet generator

[Monique]

Very interesting thread.

My new to me WAFI has a Onan genset in an enclosed box, inside the sound proofed engine room. It also has a separate path water muffler (which I have to study) and its quiet enough that the PO admitted leaving the boat with the ONAN running.... on some occasions. Installation is very quiet.

If you get an ONAN, on some sailboat installations, their raw water impellers are fragile and require changing every 100 hours. The theory is that if the genset is running when underway, the water flow around the hull causes suction at the through hull fitting. The suction causes early impeller failure. I believe all generators would be subjected to this problem.

This could be inconvenient if you need lots of genny hours to tend to your needs. A common solution for the Onan problem is to install a Jabsco pressure pump in the raw water line; dependability doubles. I will also run SPEED SEAL LIFE on the genset. Kit already in hand...

3 X 130 Kyocera panels have also been bought.

We are likely to meet somewhere in the world's boondocks in the future. I will look for a shiny new Oyster! Lovely choice. Enjoy!

 

[MapisM]

The Mastervolt Quattro operates like that

You meant the Victron Quattro, surely?
Btw, I'm debating this topic with the Victron master, BartW of this parish, and my understanding is that the Multiplus can do the same at a slightly lower cost, for any given power.

PS: I fully agree that the unit should be able to supply the additional power from batteries regardless of whether it's connected to the shore power or to the genset.
In fact, depending on how you connect it, the unit might even be unaware of the difference.

 

[Deleted User YDKXO]

You meant the Victron Quattro, surely?
Btw, I'm debating this topic with the Victron master, BartW of this parish, and my understanding is that the Multiplus can do the same at a slightly lower cost, for any given power.

Whoops, of course you're right and I should know because I installed a Multiplus on my previous boat. Bart can explain much better than me what the difference between the Quattro and Multiplus is but AFAIK, the Multiplus can only handle AC input from one source ie either generator or shorepower whereas the Quattro can switch between sources. I had my Multiplus connected to shorepower only and it worked very well once I'd got to understand the menus. One thing you do need to understand is that the Multiplus cannot sense the max available current from the shorepower; you have to set it yourself. This means that you need to reset the max current it will take from the shorepower according to the connection you have ie 16 or 32 or 63A and thats a PITA if you're cruising to different marinas. Also because the Multiplus doesn't switch in the generator automatically, if the shorepower goes down and you have the aircon running, it will try to flatten the batteries although there is a setting in the battery monitor menu somewhere for the minimum battery voltage. Btw what I did was leave my old Mastervolt (yes Mastervolt!) charger connected to the generator circuit so I had a degree of redundancy. I did have some issues with the Multiplus stopping operation on a couple of occasions (solved eventually by rebooting it) and it did fail once completely requiring replacement under warranty but I was still able to keep the batteries charged by using the generator and the old Mastervolt charger
The Multiplus is a good piece of kit despite the issues I had and I may fit one on my new boat too

 

[penfold]

If you get an ONAN, on some sailboat installations, their raw water impellers are fragile and require changing every 100 hours. The theory is that if the genset is running when underway, the water flow around the hull causes suction at the through hull fitting. The suction causes early impeller failure. I believe all generators would be subjected to this problem.

This could be inconvenient if you need lots of genny hours to tend to your needs. A common solution for the Onan problem is to install a Jabsco pressure pump in the raw water line; dependability doubles. I will also run SPEED SEAL LIFE on the genset. Kit already in hand...

If the engine mounted SW pump is that chocolatey and you have a external pump what's the point of having it? Either run it with no impellor fitted or bypass it completely and perhaps double up on the external pumps for redundancy.

 

[david_bagshaw]

We have had an Onan 7.5Kva with halyard exhaust dewatering kit makes for a quiet genny, along with a 3kva victron inverter for the night time 240 load, (Wife's PD Home Dialysis machine) along with moderate loads in the day,great for kettle boiling, ironing etc while underway.

Not had problems with the sea water pump, however since 1999 two impellers have failed, both when underway in shallow waters. Otherwise impellers have been changed every other year. set has now done 3500 hours.

 

[Monique]

If the engine mounted SW pump is that chocolatey and you have a external pump what's the point of having it? Either run it with no impellor fitted or bypass it completely and perhaps double up on the external pumps for redundancy.

Valid point. These Jabsco are very reliable though...

 

[Lozzer]

Sorry guys have been away in the UK at meetings with boat builders.

To answer question about the water pump princess believed that the P85 would run continually with genset hence not putting a 24v water pump in or and inverter on the 240v pumps.

Because we like to go dead ship at night it meant the owner and guests couldn't brush their teeth or flush the toilet. To overcome this I could have put the pumps on inverter but it was easier and cheaper to put a 24v pump in plus I got a failover. Which has been used.

The original batteries on the P85 were 6 x 120ah @ 12v. So this graves us not a lot when turning genny off at night. Last summer we killed two sets of batts. I have replaced now with a much better solution and we can last a fair while now on batts I'm pleased to say.

With regard to generators I'm trying to hold off making the decision so I can go to Southampton BS first and do the rounds hopefully Oyster will give me the time.

 

[Lozzer]

I had a NL small gen in a brand new boat I chartered 2 yrs ago. About 6 kva. I hated it and wouldn't buy NL at this small size. Kohler and Onan is where it's at IMHO. Lozzer you might want to compare specs for the particular size you want. I chose Onan because at the size I needed it had a shaft driven raw water pump while kohler had belt drive and I let that be the tie breaker in an otherwise score draw. One less thing to maintain

Lozzer with maybe 3 gensets plus a main engine and gearbox you should get a Wasp or Reverso oil change pump to all 5 sumps. Makes maintenance easy. Maybe you had this on p85 so are already used to it

Hi JFM

the p85 doesn't have the oil change facility that you have on the Sqdn 78. Had we specd the boat I would have put it on for sure. Servicing the gensets is ok if you remove the air filters on the engines.

I have specd it on the sailing yacht along with fuel cleaning system and sea chest for raw water intake. Engine driven emergency pimp as well.

They are starting to gel the mould any day now so project becoming reality rapidly. Now I have the project to sell the P85 as well. Fingers crossed I don't have to run two boats! Guess I had better get selling....

 

[jimmy_the_builder]

emergency pimp

An essential on every large med boat

 

[Deleted User YDKXO]

An essential on every large med boat

Did anyone read today's piece in the Telegraph about superyacht crew training? Seems like one of the duties of crew when Premier League footballers are on board is to make sure that the girls are all cleared off the boat before the wives arrive

 

[MapisM]

To answer question about the water pump princess believed that the P85 would run continually with genset hence not putting a 24v water pump in or and inverter on the 240v pumps.

Aha, I see.
Well, in this case, surely fitting a DC pump was an easier way to grant both redundancy and service continuity with no genset, compared to fitting an inverter AND a second AC pump.
Btw, I perfectly understand the wish to not keep a genset running at night, because I do exactly the same.
And I also don't have any inverter (yet - probably going to fit one), but all my fridges are 24VDC.
Don't you have any AC fridges on the P85? I would have thought that at least the big one in the galley was powered by an AC motor...

All that aside, I don't think I would be alone in appreciating a build thread on a beautiful Oyster yacht, if you want/like/have the time/can post it.
In any case, all the very best for your project(s)!

 

[ARE]

Hi Lozzer,

We do offer half day engineer training sessions. Please PM me for details.

With regards to noise, I would suggest you look at sound levels very carefully as some manufactures rate differently. Some rate at 7m distance others like Onan rate at 1m. Some rating's also exclude load or 1/4 loaded, while some are at full load.

I would also pay particular attention to the exhaust system, As this can have a large affect on the noise levels. You could fit a larger aqua lift muffler with a water separator, however there are options like fitting dry silencers, then injecting water. But ultimately space can become a issue.

Which model Oyster are you getting?

Anthony

 

[Lozzer]

Hi Anthony

My boss has ordered the first Oyster 745. It was announced last year and delivery is spring 2016 although we have decisions to make early in build process.

I did notice he noise levels at different ranges but thank you for pointing that out. I have a noise meter on my iPad so will flash up current gennys and see what they come out to..

I think we have spoken before Anthony are you the Cummings Onan dealer?

At the moment I service my two onan 27.7kw gensets however would certainly consider doing a half day training session. Do you get involved I t the engine side as well. Yacht is spec'd whoa cummins . I would be interested to know if you can self service and maintain warranty.

I have to say that I know Onan and therefore have a comfort factor there. Plus the shared spares, single point of contact etc etc means they have a lot going for them.

JFM. Northern lights I see as big boat stuff.

MapisM. There are inverters for the fridges but the cable run would be crazy.

I hope to run a thread on the build but as of yet not a lot to see. Mould is complete and they will start to put gel coat on any day now. All I have to show at the moment is the spec.

 

[ARE]

Hi Anthony

My boss has ordered the first Oyster 745. It was announced last year and delivery is spring 2016 although we have decisions to make early in build process.

I did notice he noise levels at different ranges but thank you for pointing that out. I have a noise meter on my iPad so will flash up current gennys and see what they come out to..

I think we have spoken before Anthony are you the Cummings Onan dealer?

At the moment I service my two onan 27.7kw gensets however would certainly consider doing a half day training session. Do you get involved I t the engine side as well. Yacht is spec'd whoa cummins . I would be interested to know if you can self service and maintain warranty.

I have to say that I know Onan and therefore have a comfort factor there. Plus the shared spares, single point of contact etc etc means they have a lot going for them.

JFM. Northern lights I see as big boat stuff.

MapisM. There are inverters for the fridges but the cable run would be crazy.

I hope to run a thread on the build but as of yet not a lot to see. Mould is complete and they will start to put gel coat on any day now. All I have to show at the moment is the spec.

Hi Lozzer,

Yes we have spoken before, I am the aftermarket manager for Cummins Onan factory not a dealer. I look after all of the OEM's including Fairline, Princess, Sunseeker, Ferretti and Beneteau to name but a few.

Anyone is welcome to visit our office and discuss there requirements and as I said before we offer half day training sessions, but this only covers generators as propulsion engines are covered by Cummins UK at Wellingborough.

Good luck with the new boat, where is it being built Southampton or Wroxham?

Anthony

 

[Lozzer]

Boat is being built in Southampton.

Being based in Spain will mean a lot of traveling and nights in hotel during build process. Such is life, it's going to be a great experience I believe.

Can you tell me why you measure noise at 1m and your competitors do it at 7m.

 

[ARE]

Basically it's to make there figures look better, the same as with load.

No load less noise. But people only every look at dBa figures not the distance and no load or full load.

Pm me your email address and I will send you a convertion program.

 

[MapisM]

Pm me your email address and I will send you a convertion program.

I struggle to imagine a conversion logic which could reliably work with any engine/distance/load.
I suppose that you have also the Onan numbers at 7m/no load (which btw was the sense behind Lozzer question, as I understood it - why not just publish those numbers, rather than some other which are not comparable?), which is fine.
But converting NL (or whatever) numbers from 7m/no load to 1m/full load based on some algorythm, that doesn't sound very scientific, imho...

 

[ARE]

I struggle to imagine a conversion logic which could reliably work with any engine/distance/load.
I suppose that you have also the Onan numbers at 7m/no load (which btw was the sense behind Lozzer question, as I understood it - why not just publish those numbers, rather than some other which are not comparable?), which is fine.
But converting NL (or whatever) numbers from 7m/no load to 1m/full load based on some algorythm, that doesn't sound very scientific, imho...

Of course you are right, the convertion can not include load, however it is something you have to take into consideration.

I am not saying there is anything wrong with the way manufactures measure sound levels, I just wanted to make sure Lozzer was comparing apples with apples.

I also don't understand why you would rate at no load? Surly no load you would switch the generator off.

 

[Deleted User YDKXO]

I struggle to imagine a conversion logic which could reliably work with any engine/distance/load.
I suppose that you have also the Onan numbers at 7m/no load (which btw was the sense behind Lozzer question, as I understood it - why not just publish those numbers, rather than some other which are not comparable?), which is fine.
But converting NL (or whatever) numbers from 7m/no load to 1m/full load based on some algorythm, that doesn't sound very scientific, imho...

Measuring noise levels is difficult for any kind of equipment. As ARE says, by convention it is measured at various points around the equipment at either 1m or 7m radius and normally, at least in my industry, at full load but the problem is simulating full load conditions plus of course ensuring that the measurements are not affected by other factors. I would always treat noise level figures published by manufacturers with let's say a degree of scepticism because of course its in their interest not to overstate noise levels. The other obvious issues are that noise levels of say, a generator, could vary considerably according to where and how it's installed. Also, loose or degraded soundproofing material could significantly increase noise levels. FWIW and IMHO, probably the best indication of how quiet or noisy generators are is the experience and recommendation of others

 

[MapisM]

I also don't understand why you would rate at no load? Surly no load you would switch the generator off.

Yup, agreed. I was questioning the possibility of making different noise numbers comparable just with a program, not the principle that "your" system is probably better than "their".
Otoh, from a user standpoint, comparability is what really matters.
I mean, if the common practice (wrong as it may be) is 7m/no load, I'd rather see also Onan numbers measured in that way, than making estimates...