Artemisia - new build thread for a Prestige 680

[westernman]

explanation is that 6kw for a whole house is exceptionally small. You can't use it as a data point in specifying another house or boat. Indeed, are you sure about the 6kva? Thats about 24 amps.

It is 30 amps. Yes I am sure. It is the standard size supply in France for a house. You can get a bigger supply, but the monthly cost is a lot higher (I think about 3X).

Why can't you use it for specifying another house or boat?

The air conditioning is surely similar, the electric cooker, fridge, freezer, kettle, nespresso machine, washing machine, dish washer. (OK the central heating is sometimes gas in a house - although in most towns in France it is electric as well).

Why would you suddenly need more than 3X for a boat which in volume terms is considerably smaller than a house?

The additional loads are battery charging. But if you use one of those intelligent Victron things it will not put 6KW (over 400A at 12V) into the batteries if you need it for the airconditioning.

Also the inverter seemed very small (only 2KW I think). For a boat like this I would have thought you would want about 8KW of intelligent inverter and about 7-8KW generator. But what do I know - which is why I am asking the questions.

 

[Deleted User YDKXO]

Why would you suddenly need more than 3X for a boat which in volume terms is considerably smaller than a house?

You must be very frugal with your electricity usage at home. We have a smart meter on our electricity supply at home and I regularly see 15kW on it and thats with oil fired central heating. A boat may be smaller than a house but potentially you're still using the same number and type of domestic appliances plus aircon. On a 68ft boat with potentially up to 10 people on board I would specify a 20kVa generator minimum

 

[MapisM]

It is 30 amps. Yes I am sure. It is the standard size supply in France for a house.

Fwiw, in IT the standard supply for domestic single phase is 3 kW, 4.5 or 6 being also available on request.
Actually, there is also a 10% peak allowance, so in practice 6.6 is the max. For higher needs, you can get 3-phase.
However, nobody in his right mind would consider using electricity for heating, hot water or cooking - gas is much more efficient for those purposes, and the supply grid is very extended.

 

[westernman]

Fwiw, in IT the standard supply for domestic single phase is 3 kW, 4.5 or 6 being also available on request.
Actually, there is also a 10% peak allowance, so in practice 6.6 is the max. For higher needs, you can get 3-phase.
However, nobody in his right mind would consider using electricity for heating, hot water or cooking - gas is much more efficient for those purposes, and the supply grid is very extended.

I still don't understand the need for > 20KW in a boat.
Do you?

 

[Hurricane]

I still don't understand the need for > 20KW in a boat.
Do you?

Air Con?
Kettle
4 fridges
Charging batteries which, in themselves, are running cranes, bathing platforms and passerelles etc.
The lighting loads can be high as well.

and then you have to be able to start them - start up loads are greater than the running loads
Actually, I'm sure that you would actually use more electricity on a boat than a house,

 

[vas]

I still don't understand the need for > 20KW in a boat.
Do you?

insulation on your home (or at least mine!) is 80mm plus and overall mass of the wall is usually substantial, compare that to 8-10mm max grp on the superstructure of a boat. There are plenty of windows organised and oriented in a way that you can easily have through currents cooling the place, and double glazing at least, not sure double glazing is something used often on boats. Pergolas, tree shading etc can also help in July, Aug, not much of that either on a boat. Hence I only need aircon on 4 spaces and I can get away with 25Kbtu (iirc) Ask JFM how many btus are in Match alone
Mean height inside a boat is what 2m 2.2m max? On a house you start at 2.5m (legally in most places and sky's the limit)
Get these in, plus solar panels for hot water 10m a year in the Med and you get the whole thing coming together.

I think most of the difference is in cooling loads and in mantaining an off grid system.

get's quite off topic though so we should bring the focus back to Artemisia

V.

 

[westernman]

insulation on your home (or at least mine!) is 80mm plus and overall mass of the wall is usually substantial, compare that to 8-10mm max grp on the superstructure of a boat. There are plenty of windows organised and oriented in a way that you can easily have through currents cooling the place, and double glazing at least, not sure double glazing is something used often on boats. Pergolas, tree shading etc can also help in July, Aug, not much of that either on a boat. Hence I only need aircon on 4 spaces and I can get away with 25Kbtu (iirc) Ask JFM how many btus are in Match alone
Mean height inside a boat is what 2m 2.2m max? On a house you start at 2.5m (legally in most places and sky's the limit)
Get these in, plus solar panels for hot water 10m a year in the Med and you get the whole thing coming together.

I think most of the difference is in cooling loads and in mantaining an off grid system.

get's quite off topic though so we should bring the focus back to Artemisia

V.

Why only a 2KW inverter?

 

[MapisM]

I still don't understand the need for > 20KW in a boat.
Do you?

Vas has a point, we're way o/t on this power requirements debate, but just to answer your Q: yes, I do.

Actually, on my own boat I very rarely see AC absorptions above 16/18 amps, and in fact I can run just about everything from my 6.5 kW genset - including the most power hungry equipment, i.e. the two A/C compressors (which are not very big actually, 17k BTU each, as I recall). I do have gas for the cooktop, though.

That said, for some reason my boat is less power hungry than any similar size boats that I've seen - don't ask me why, I usually don't bother investigating non-problems!
In fact, I've seen boats not much bigger than mine using 80+ amps, without even running each and every onboard toys.
I suppose that has also to see with MoBoers not being used (nor willing) to be careful about power management...
...then again, I guess it's pointless to bother with that, if avoidable by just fitting a big genset.
After all, in the context of a boat with a couple of engines possibly with a thousand+ hp each, feeding a 20kVa gennie is no big deal!

 

[Anders_P42]

Air Con?
Kettle
4 fridges
Charging batteries which, in themselves, are running cranes, bathing platforms and passerelles etc.
The lighting loads can be high as well.

and then you have to be able to start them - start up loads are greater than the running loads
Actually, I'm sure that you would actually use more electricity on a boat than a house,

Plus Gyro, immersion water heater - these two could use 3KW alone

 

[wakeup]

explanation is that 6kw for a whole house is exceptionally small. You can't use it as a data point in specifying another house or boat. Indeed, are you sure about the 6kva? Thats about 24 amps.

I think MC might be mistaken. We have a villa in SoF and it IS limited to 60amps. If you try and draw more than that it trips and the meter. By my calc that is about 14w. We don't run A/c but I could easily see that creating a problem with start up amps drawn. I have about 1.8kw continuous on the pool pump also which would draw the margin down even further for other appliances.

When you buy a new supply in SoF, the local energy company's default trip rate is 20amps. You have to ask nicely for them to put you up to 60amps (Single phase of course). In fact we might have even paid to have it up graded but don't remember.

 

[westernman]

I think MC might be mistaken. We have a villa in SoF and it IS limited to 60amps. If you try and draw more than that it trips and the meter. By my calc that is about 14w. We don't run A/c but I could easily see that creating a problem with start up amps drawn. I have about 1.8kw continuous on the pool pump also which would draw the margin down even further for other appliances.

When you buy a new supply in SoF, the local energy company's default trip rate is 20amps. You have to ask nicely for them to put you up to 60amps (Single phase of course). In fact we might have even paid to have it up graded but don't remember.

The default is 6KW (which is 30amps).
Having more costs more (even if you do not use it).

Here are the charges for residential:-

 

[westernman]

The default is 6KW (which is 30amps).
Having more costs more (even if you do not use it).

Here are the charges for residential:-

View attachment 55424

I don't have a pool - but I do have a big air conditioner with air conditioning in all rooms on all three floors. I have never tripped the 6KW supply we have.

My mum has a big pool, but no air conditioning. She has 6KW and electric heating and has never tripped either.

A friend in Paris has electric heating, electric cooking and lots of lights. I did trip his supply once turning on the nespresso machine (along with the oven, three rings on the stove at high setting, the dish washer and the radiators in the middle of winter when it was snowing). But that was the only time.

We upgraded the supply in our restaurant from 6KW to 12KW because we tripped all the time in the first few days. (It was actually a dinner guest who did the necessary change to the meter).

 

[Forty_Two]

Can some one explain this to me?

It's the startup loads. With your continuously rated home supply the volt drop when your ac starts up is limited to the cable sizes back to the sub station. The voltage there won't dip as it has a nice fat supply. The geny however has no reserve & just takes the hit, slows down when it runs out of power & down go the volts making things worse.

You can't compare a geny at max output with your home supply at the same power rating as the home source of the power is able to deliver larger short term overloads for motor startups.

The result is you need an oversized geny, staged compressors or a VFD soft start setup to keep a lower sized geny.

My 6kva geny used to nearly stop when my 36,000btu chiller kicked in, my nice Onan 11kva just smiles at the load.

 

[Pinnacle]

Ahem.....gents. Enough of the electrickery.........can we please get back to the pics/discussion of this fine craft? :encouragement:

 

[Andrew M]

Yep, am loving hearing about the build of your stunning new boat MAFWeiss and I think the blue externals look just superb.

So what's the next stage ? If you've specced most of what you can change, is it just regular updates on the build progress ? Do keep the photos coming.

We had a look over the 680 at LBS yesterday, what a boat, the flybridge entertaining areas are just immense !! And, of course, that forward master is a dream of a cabin, I like the way Prestige have given real priority to the master cabins even on some of the smaller models too.

Andy

 

[MAFWeiss]

Yep, am loving hearing about the build of your stunning new boat MAFWeiss and I think the blue externals look just superb.

So what's the next stage ? If you've specced most of what you can change, is it just regular updates on the build progress ? Do keep the photos coming.

We had a look over the 680 at LBS yesterday, what a boat, the flybridge entertaining areas are just immense !! And, of course, that forward master is a dream of a cabin, I like the way Prestige have given real priority to the master cabins even on some of the smaller models too.

Andy

Thank you Andy! There are still more discussions to be had on the spec over the coming weeks, e.g. entertainment system, extra electronics e.g. wifi/mobile arials/routers, anchor chain (galvanised or stainless steel), PTZ and fixed cameras etc. Also as more pics come through of the ongoing build (been promised regular photos from the factory), I am sure there is plenty more mileage in the build thread.

 

[MAFWeiss]

Breaking news… and you heard it and seen it here first!!! The Prestige 680 has won the Motor Boat 2016 Award for best flybridge over 60 feet. I knew I had picked a winner :encouragement: :triumphant:

 

[Greg2]

Well deserved if what I have read on here is anything to go by. Wanted to have a look over the one at LIBS on Sunday but ran out of time........bad planning!

Anyway, looks great so many congrats.......exciting times!

 

[rafiki_]

Looking forward to seeing the boat at LIBS on Thursday.

 

[BartW]

........... anchor chain (galvanised or stainless steel),

I'm a big fan of stainless steel !, and long enough !
we used to have a 95m galavanised 12mm chain, and this was alway's a hassle, as at each anker recovery, someone had to climb in the crew cabin, to have acces to the ancer locker, for spreading out the pile of chain. The pile did obstruct the passage of the chain through the deck opening.
We tried different modifications but nothing cured the problem. (sometimes we do up to 3 or 4 anker recovery's a day)

Last year we have replaced this chain with a brand new 150m stainless steel chain, and this is a absolute winner, this chain is much more smooth, and 'flows' on the bottom of the locker, no pile up, and also this length has been usefull on several occasions; in Croatia there are many moorings where you have to use the anker instead of bow lines, also anchorages in bay's towards the shore, ... with the long chain its much more easy to have enought length out, without making the wrong estimation of distance to shore / dropping the anker too early (a bit difficult to explain)

so yes my advice: 130...150m steenless steel chain !

congratulations on the new boat boat ! and many thanks for sharing the build process with us,