Marine system design
- Thread starter nicklee
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
ranger58sb
Guru
- Joined
- Aug 21, 2013
- Messages
- 7,349
- Location
- Annapolis
- Vessel Name
- Ranger
- Vessel Make
- 58' Sedan Bridge
If you are planning for some solar panels and/or want to upgrade your inverter or
alternator(s) then considering 24v might make some sense. Not so much for 48v.
A DC to DC converter could keep your starting batteries charged and run 12v loads.
Redoing everything from scratch will cost a lot of scratch, though.
Last edited:
jungpeter
Guru
Hi Nicklee. Assuming you're asking for help in the ELECTRICAL system (re)design of your 40 ft boat, I suggest that's a big ask from an open source (this forum, for instance) and a resultant big risk on your part. I believe it's money well spent to get professional guidance on the front end in attempting a complete electrical redesign of a substantial 40 ft powerboat. WAY cheaper, and WAY safer than collating a passel of well-meaning but often fragmented advice from total strangers on the WWW.
I would suggest you seek out a local professional marine technician ABYC-certified in at least Marine Electrical and Marine Systems. Ask (and pay) him or her to both survey your existing setup, and recommend an update (if needed) to suit your purposes. From that baseline, you can decide how to proceed.
You may well find that you don't actually need a redesign; rather some judicious upgrades and/or repairs may suit your needs. And if you do actually need a full redesign, making system recommendations as fundamental as voltage standards (12vdc vs 48vdc, for instance) are best left to a professional, at least in the design stage.
Execution of suggested repairs, replacements, and improvements can then proceed at your discretion, in a well thought out and cohesive manner, in full accordance with your timeline and budget.
Regards,
Pete
Comodave
Moderator Emeritus
- Joined
- Jul 2, 2015
- Messages
- 22,509
- Location
- Au Gres, MI
- Vessel Name
- Black Dog
- Vessel Make
- Formula 41PC
I always recommend getting an ABYC certified marine electrician however that is almost impossible to do, at least in my area. There aren’t that many around.
C lectric
Guru
Thinking about a 24v or 48v system with a step down transformer to 12v is this a good idea??
NO!!!!
I agree with the others, get some qualified help. Doing this kind of design over the net is fraught with problems.
I don't mean to insult you but you have already indicated a poor understanding of AC and DC systems.
A transformer is NOT going to help with dropping the 48VDC or 24VDC to 12VDC. There are devices that will help but again not easily over the internet.
At this end proper terminology becomes EXTREMELY important.
NO!!!!
I agree with the others, get some qualified help. Doing this kind of design over the net is fraught with problems.
I don't mean to insult you but you have already indicated a poor understanding of AC and DC systems.
A transformer is NOT going to help with dropping the 48VDC or 24VDC to 12VDC. There are devices that will help but again not easily over the internet.
At this end proper terminology becomes EXTREMELY important.
C lectric
Guru
Thinking about a 24v or 48v system with a step down transformer to 12v is this a good idea??
NO!!!!
I agree with the others, get some qualified help. Doing this kind of design over the net is fraught with problems.
I don't mean to insult you but you have already indicated a poor understanding of AC and DC systems.
A transformer is NOT going to help with dropping the 48VDC or 24VDC to 12VDC. There are devices that will help but again not easily over the internet.
At this end proper terminology becomes EXTREMELY important and you need to know the terminology.
NO!!!!
I agree with the others, get some qualified help. Doing this kind of design over the net is fraught with problems.
I don't mean to insult you but you have already indicated a poor understanding of AC and DC systems.
A transformer is NOT going to help with dropping the 48VDC or 24VDC to 12VDC. There are devices that will help but again not easily over the internet.
At this end proper terminology becomes EXTREMELY important and you need to know the terminology.
OldDan1943
Guru
- Joined
- Oct 2, 2017
- Messages
- 10,663
- Location
- USA
- Vessel Name
- Kinja
- Vessel Make
- American Tug 34 #116 2008
Document everything with line drawings
Hippocampus
Guru
- Joined
- Jul 27, 2020
- Messages
- 4,184
- Location
- Plymouth
- Vessel Name
- Hippocampus
- Vessel Make
- Nordic Tug 42
+1 on ABYC designer. Another reason to do so is if you ever have any electrical fire even if your home made design is good and your work is good you may have troubles with any insurance claim.
Putting a 48amp EV charger into our garage. Simple - 60amp breaker and correct sized wire. Not rocket science. But using a licensed electrician and pulling a permit just to keep house insurance vender happy. Prior owner had an invert/charger fail. Fire extinguisher went off. Claim made and 100% of replacement and clean up paid. Nothing wrong with wiring, breakers or design. Sh-t happens. Things were factory original.
Putting a 48amp EV charger into our garage. Simple - 60amp breaker and correct sized wire. Not rocket science. But using a licensed electrician and pulling a permit just to keep house insurance vender happy. Prior owner had an invert/charger fail. Fire extinguisher went off. Claim made and 100% of replacement and clean up paid. Nothing wrong with wiring, breakers or design. Sh-t happens. Things were factory original.
OldDan1943
Guru
- Joined
- Oct 2, 2017
- Messages
- 10,663
- Location
- USA
- Vessel Name
- Kinja
- Vessel Make
- American Tug 34 #116 2008
2 things to remember:
12vt tickles
120vt just might stop your heart and ruin your partner’s day or perhaps ‘make her day’
Jc180
Senior Member
- Joined
- Aug 22, 2018
- Messages
- 232
- Location
- U.S.
- Vessel Name
- Salty Dog & Last Dragon
- Vessel Make
- Gulfstar 47 Sailmaster & Mainship 34 MK 1
Echo previous posts about defining problem to be solved. Would offer three other comments: 1. Think this forum is a great place to start learning and discussing. 2. Be wary of the professional help. Likely very willing to take your money to solve the undefined problem. 3. If thinking solar, can utilize 24 or 48 vdc panels and via the controller get 12v output.
Mambo42
Guru
- Joined
- Oct 26, 2021
- Messages
- 988
- Vessel Name
- Endless Summer
- Vessel Make
- 1979 Defever 49
That is exactly what I did as well and it works perfectly fine for me, had to make some changes though.
I had a 12 V system throughout the whole boat, but I wanted to add much more solar and much more Ah in the batteries. I was thinking about 1200 to 1600 Ah of Lithium in a 12 V system, but the electricians talked me out of it.
They basically told me that my cable had to become so thick that it would not make any sense anymore.
So what I now have is a 24 V house bank at 1400 Ah Lithium. Next to that I have a 24 V system for my bow thruster, stern thruster and for my anchor winch (that used to be 12 V 1500 W, but is now 24 V at 1700 W). In addition I have 4 x 12 V start battery for the engines.
Most of the 12 V systems I kept at 12 V, simply used quite a few DC to DC converters and that does not give me any problems.
The house bank now feeds a 24 / 8000 / 200 Victron Quattro which supplies the boat with 220 V AC. The shore power and the generator feed into the Quattro and the solar panels feed into the batteries via MPPT controllers.
It sounds a bit outlandish to have so many different Voltages on 1 boat, but if I want to buy new navigation equipment I can just buy 24 V from now on and thus slowly change more and more items to 24 V, reducing the load for the DC /DC converters.
Instead of having to deal with extremely thick 12 V cables I now have 120 mm2 cables for the main systems and 70 mm2 for the other systems (winch, bow thruster etc).
Am not saying you should do it this way, but it can be done and I am very happy with it. I basically doubled my housebank from almost 15 Kwh to around 30 usuable. And that was for me the most important item, since it opened up a completely different way of using the boat. In the past I was running on generator all the time, which is something I don't like when I am asleep. Now I can run the boat, on anchor, completely off solar during the day time and off the batteries during night time. I can even run an airco plus the stabilizers at nightwith no fear of emptying the batteries, no more need for a generator.
Once the engines start I can charge the batteries with around 350 Amps per hour and if on shore power I can charge them with 200 Amps per hour. The solar will charge them with roughly 100 Amps per hour at 24 V.
It might be something to take into consideration, but indeed get some qualified electricians to draw it out for you.
Last edited:
As others have said, you need to provide more details, but it is obvious you don't know enough to know what you don't know.
Which is ok. We all start at 0. Start high level on WHAT you want to do. What equipment you need to power, is it AC or DC, what voltages are required. AC voltage for a boat that stays in the US is different than a boat in Europe or a boat that travels the world.
Once you get the equipment requirements listed, then you can get into how to power the devices.
Later,
Dan
Similar threads
