Switching from 12V to 24V

[Pelagic]

People who know how to use Radar,..... Use it!

Those who don't..... Don't!

Re AC voltage outlets:

On the wiring refit, I added outlets to a number of convenience areas including all the cabins so that guests can charge their Smart Phones. Tablets, Kindles, wireless headphones etc..

I even put a heavy-duty waterproof socket on a seperate breaker in the cockpit.

Its dual purpose is to provide power for small TIG welding jobs, but mostly an anchor convenience as we tend to live in the cockpit in the evenings

[john61ct]

Just to followup, OzePete confirmed the known-good but cheap Chinese 24-to-12V converters he recommends, at least for lower load devices.

http://www.cruisersforum.com/forums/....php?p=2754333

This makes converting to a 24V based system more cost-practical to me, **if** there's a stronger reason for doing so on a small boat than just saving copper expense.

Originally Posted by john61ct

Sounds like you're dead set on 24V as your default.

Do your field testing close to home, carry spares of stuff you're not dead sure about.

Use converters to get you 12V where needed, and carry spares of those.

Besides the bigger pricey Victron ones, OzeFridge recently posted a specific example of a little cheap one he trusts for his fridge electronics.

[DeValency]

Agree 24VDC network is more efficient but you want to maximize the number of devices that can run on 24V and that’s an expense... at any case you’ll need to maintain a separate, even small, circuit of 12V drawing from one of the house 12V batteries, as there are always all kind of devices and instruments that comes only with the very common 12V rating.

Personally, I prefer keeping things simple and would stay on a pure 12VDC system plus inverted to 115VAC (yeah, we have strange standards in the US )

[tarian]

Originally Posted by DeValency

Agree 24VDC network is more efficient but you want to maximize the number of devices that can run on 24V and that’s an expense... at any case you’ll need to maintain a separate, even small, circuit of 12V drawing from one of the house 12V batteries, as there are always all kind of devices and instruments that comes only with the very common 12V rating.

Personally, I prefer keeping things simple and would stay on a pure 12VDC system plus inverted to 115VAC (yeah, we have strange standards in the US )

No a simple down voltage dropper 24 v to 12v
From the 24 volt main feed is all you need take a cable run it to the converter run cable off converter to 12 volt panel.
I have a main 24 v panel with a smaller 12 volt beside it no issues.
as for 110 volt sockets or 230 volts of the inverter dont see the point I have installed in each cabin (4),usb plugs off my 24 volt system that charges all small laptops tablets , mobile phones . this keeps the voltage down to the cabins, less wire and less intrusive.
Only 230 volt sockets come alive when shore powered. I appreciate people go sailing in their condos now and need washing machines, hair-dryers, microwaves, and PlayStation, me I like it simple

[Cadence]

Originally Posted by DeValency

Agree 24VDC network is more efficient but you want to maximize the number of devices that can run on 24V and that’s an expense... at any case you’ll need to maintain a separate, even small, circuit of 12V drawing from one of the house 12V batteries, as there are always all kind of devices and instruments that comes only with the very common 12V rating.

Personally, I prefer keeping things simple and would stay on a pure 12VDC system plus inverted to 115VAC (yeah, we have strange standards in the US )

[noelex 77]

Originally Posted by DeValency

Agree 24VDC network is more efficient but you want to maximize the number of devices that can run on 24V and that’s an expense... at any case you’ll need to maintain a separate, even small, circuit of 12V drawing from one of the house 12V batteries, as there are always all kind of devices and instruments that comes only with the very common 12V rating.

24v devices are, as rule, no more expensive than 12v devices. In fact, they are more often than not exactly the same devices. It is not difficult to design a power supply that will take 12 or 24v and this is what most equipment manufacturers do. Things that require electric motors such as water pumps etc are voltage specific, but it is rare to find a model that is not available in 24v.

There is generally no seperate 12v house bank on modern boats with a 24v system. The 24v house bank usually consists of 6v or 12v batteries, but these are wired in series to provide 24v only. If 12v is required a 24/12v converter/s is used.

[tarian]

Originally Posted by DeValency

Agree 24VDC network is more efficient but you want to maximize the number of devices that can run on 24V and that’s an expense... at any case you’ll need to maintain a separate, even small, circuit of 12V drawing from one of the house 12V batteries, as there are always all kind of devices and instruments that comes only with the very common 12V rating.

Personally, I prefer keeping things simple and would stay on a pure 12VDC system plus inverted to 115VAC (yeah, we have strange standards in the US )

Sorry missed a bit in you quote , now I personally thing speculation is only good with he facts , as I have a 24 volt boat here is the facts,
The cabling is smaller in a 24v bolt so if cabling from scratch it is cheaper, 24 v is more efficient at the higher loads , high inverters and windlasses taking up large anchors, all pumps and equipment is the same price for 12 volt system, if anything I find that I can get it cheaper as it sits on shelf's or warehouses and you get it for a discount , I got Cafero 24 volt fan half the price of the equivalent 12 v it tkae a little investigating to find 24 volt specialist equipment but I have found this interesting because you find other cool stuff
At the moment I have my auto pilot ,and VHF and my Navtex only on 12 volts I have 7 spare switches on my 12 volt panel , all other systems are run of my 24 volt system
So a 24 volt sysytm is also very simple and 230 volt mains with a 1500w inverter

[DeValency]

Sorry all — I’m also an electrical engineer and a sailor for the last 30 years. To my humble opinion, at any sailboat under 60’ having an additional 24VDC system doesn’t make much sense. The standard always available parts and devices are rated to 12V. You are going to replace all your existing with 24VDC rated devices etc... does this make sense? The distances over a standard sailboat are not that long that you need higher voltage to overcome drops...
and why 24V and not 48V - if you really want to become a commercial rated vessel?...
There are so many better things to waste our money on a boat - solar, wind gen. And how about a great new asymmetrical? Lithium batteries etc etc.
But if you really have to - set a separate 24V circuit, power panel, switches etc. as you will always need to keep a 12VDC circuit - that’s the only way to set this. properly.
Best of luck!

[tarian]

Originally Posted by DeValency

Sorry all — I’m also an electrical engineer and a sailor for the last 30 years. To my humble opinion, at any sailboat under 60’ having an additional 24VDC system doesn’t make much sense. The standard always available parts and devices are rated to 12V. You are going to replace all your existing with 24VDC rated devices etc... does this make sense? The distances over a standard sailboat are not that long that you need higher voltage to overcome drops...
and why 24V and not 48V - if you really want to become a commercial rated vessel?...
There are so many better things to waste our money on a boat - solar, wind gen. And how about a great new asymmetrical? Lithium batteries etc etc.
But if you really have to - set a separate 24V circuit, power panel, switches etc. as you will always need to keep a 12VDC circuit - that’s the only way to set this. properly.
Best of luck!

Nonsense, if that was the case all the fishing fleet would run 12 volts, the OP is starting a boat from scratch as I am aware, so asking what set up he would install , as described 24 volts is cheaper better non voltage loss, parts are every where ,all HGVS are 24 volt run, and commercial boats , to add a simple redundancy in the system will cost peanuts to create a 12 volt drop down. Also it will handle larger windlasses and power hungary invertors and fridgees . All solar panels can be wired to 24 v no issues and the eqquivlant wind turbines in 24volts are the same price.
all marine grade pumps , and electronics and wiring, windlasses , instruments, lighting can all be bought at 24 volts , like I said comes from the horses mouth too k7 months re wiring my boat and re fitting new pumps , instruments, etc, reason not going 12 volts was the higher cost of wire, and the alterantor was 24 volts so though what the hell nothing wrong with 24 volts , 2 12 volt batteries as my starter , and one 12 volt battery for my generartor and 6 12 volt batteries for my house in series and parrelel

[coopec43]

Thanks Tarian for speaking a little common sense!

• The manufacturer says my fridge/freezer would work better on 24V
• Large inverters require 24V
• My winch is 24V (recommended by Muir - the manufacturer.)
• Larger solar systems require 24V.
• The 12V starter motor on the Perkins 4-108 will work fine on 24V.
• All instrumentation - tacho, water temp, rudder angle, oil pressure etc all work on 12V as well as 24V.
• All my LED lighting will work on 24V.

On the downside

• I will have to replace the fresh water pump.
• My oscillating fans will run at twice the speed.

NOTE: I had to replace the existing 12V alternator anyway as it was most certainly not up to the task of powering the yacht.

I wonder if Mr DeValency could list marine electronics that are available in 12V and not 24V?

What is the advantage of a 24v system over a 12v system?
https://pangeabuilders.com/what-is-t...-a-12v-system/


Clive

[sailing_jack]

One point of concern regarding cheap dc to dc converters.
They all have a high frequency oscillator to do the conversion, either by pulse width modulation or a high frequency transformer.

Cheap Chinese (and maybe other low cost suppliers) often take shortcuts with shielding. If you are wondering why your HF or VHF radio is noisy, try turning off the converters.

It is as always, Buyer Beware !

[LargeMarge]

This is 2018. A whole new world, a whole new way of seeing and being. Clive, I fully support your change. So you go right ahead.

Hey, it worked for Bruce Jenner.

[DeValency]

Originally Posted by tarian

Nonsense, if that was the case all the fishing fleet would run 12 volts, the OP is starting a boat from scratch as I am aware, so asking what set up he would install , as described 24 volts is cheaper better non voltage loss, parts are every where ,all HGVS are 24 volt run, and commercial boats , to add a simple redundancy in the system will cost peanuts to create a 12 volt drop down. Also it will handle larger windlasses and power hungary invertors and fridgees . All solar panels can be wired to 24 v no issues and the eqquivlant wind turbines in 24volts are the same price.
all marine grade pumps , and electronics and wiring, windlasses , instruments, lighting can all be bought at 24 volts , like I said comes from the horses mouth too k7 months re wiring my boat and re fitting new pumps , instruments, etc, reason not going 12 volts was the higher cost of wire, and the alterantor was 24 volts so though what the hell nothing wrong with 24 volts , 2 12 volt batteries as my starter , and one 12 volt battery for my generartor and 6 12 volt batteries for my house in series and parrelel

****
Ok, I think I should be off this trail when commercial fishing boats are what we refer to here...

* But just to close my case on few different comments I’ve red here:
- if you refit a whole boat electrics and devices, from zero, including the engine starter go with 24VDC, but!:
- Remember that in case you’re using only two house batteries and two starter batteries (to keep a standard 12V battery type in your bank) once one of the batteries fail (and it will, one day) all the 24V only rated devices and instruments and starters will stop working at that moment - enjoy the nightmare....
- Sure, if you go with 4 house batt., 4 starter batt.. you are safer, but will need to have the proper switches to bypass the faulty battery.
- Clive, I know 12V oscillating fans are cheap, but they will not run faster with 24V, they will most likely burn on the spot. Same thing with all 12V only other devices.
- Sure you can install good quality (and expensive) 24-12VDC, converters (unless you don’t like the simple way of connecting a 12V battery to a 12V separate circuit.... *** converters draw energy for their own operation *** is that what you wanted?

[noelex 77]

24v fans are not hard to find. There is no need to buy 12v fans for 24v boat.

For example all the popular Caframo models are available in 12v or 24v versions. Their newest fan the Sirocco II will run on either 12v or 24v so there is not even a seperate model for the different voltages.

[coopec43]

As you say the fans are cheap anyway so I did a search to find out just how cheap and I came across this.(See eBay advertisement below) Can you switch it between 12V and 24V or does it spin faster using 24V? That is going to worry me now!!

I'd rather not use converters if I can get away with it

I found this article quite interesting particularly as it relates to running an electric motor on higher voltages than it was designed for. Maybe if the motor didn't fly to bits it would be OK if the load wasn't too much and didn't cause it to overheat?

https://www.4qd.co.uk/docs/12-24-36-or-48v-operation/

Thanks for your help

Clive