Switch from 12V to 220/110V for internal lights and appliances?

[anaif03]

Hello guys,

I am considering upgrading all the electrical systems to use electricity from the inverter for all internal lights, electrical sockets, and appliances (except the fridge).
The navigation lights and electronics are still on 12V.

I would like to get your feedback about this idea.

Thank you
Phil

[fxykty]

Well, it’s your choice but the question is why?

Your battery provides the same 12V DC that your lights and all other DC equipment needs. Why introduce another piece of equipment that has power losses due to inverting and can go down unexpectedly for that equipment?

Bringing AC appliances onto the boat and providing AC outlets makes sense (e.g. microwave, coffee maker, electric toothbrush, etc), but why convert DC lights to lights that will still be DC but now will invert to AC and convert back to DC?

We do run our inverter 24/7 as we have an electric galley, but for anything that uses AC via a transformer to DC (e.g. laptop, monitors, router, LED light strings, etc) we cut off the AC plug and converter and wire directly to DC (including using converters 12V - 5V and 12V - 24V as needed).

[team karst]

Its lots of work replacing a two wire system with a 3 wire system. Plus, its not going to be called an upgrade by most.

[goboatingnow]

Originally Posted by anaif03

Hello guys,



I am considering upgrading all the electrical systems to use electricity from the inverter for all internal lights, electrical sockets, and appliances (except the fridge).

The navigation lights and electronics are still on 12V.



I would like to get your feedback about this idea.



Thank you

Phil

Sure assuming you have enough invertor power. Just put a transfer switch on the incoming mains. It might be a good idea to disconnect the Mains battery charger fron this circuit.

Unless you need a voltage frequency change as others have said why bother.

[Adelie]

Originally Posted by anaif03

Hello guys,

I am considering upgrading all the electrical systems to use electricity from the inverter for all internal lights, electrical sockets, and appliances (except the fridge).
The navigation lights and electronics are still on 12V.

I would like to get your feedback about this idea.

Thank you
Phil

Electricity up to 60v is considered low voltage. Above that voltage safety requirements are more stringent and there may be insurance implications.

This is why almost all EP (Electric Propulsion) systems are 48v.

Consider that, unlike a house, a small marine vessel is constantly in motion and there is usually significant moisture at hand. The potential for shorts and fires and shocks to personnel is greatly increased.

[Pizzazz]

Low voltage DC is safer and more reliable. Just connect a battery to the lamp and it works. The only reasons to go 220V AC is high power (galley, AC) and cost of the appliances (household appliances are much cheaper). You don't want 220V AC for your engine room lights, bilge pumps, etc. it is just not safe.

I can see why you would want to have a 220V TV for example (much cheaper and higher quality), so do that. I could see the case for an AC fridge or icemaker, again much cheaper. But for light fixtures, do stay 12/24V, there is plenty of inexpensive options.

[Chuck34]

Agree with others…why?
I’m old school…if it ain’t broke, don’t fix it. Nothing wrong with 12 v lighting. If it’s not bright enough, replace the bulbs with stronger LED’s. As far as electrical sockets go, I assume you already have some 120v sockets and yes, they should be connected to your inverter. 12 v sockets (cigarette lighter style), just leave as they are.

[anaif03]

Thank you all for your precious feedback. I need to rebuild the electrical system from scratch because the past owner manipulated it so profoundly that it can be fixed. So I thought having only one system in place could be more accessible. Otherwise, I need to cable the 12V for lighting in each cabin plus 220v/110V for a socket.

On top of this, as many of your said TV and other appliance are cheaper and better.
I will have a lifepo4 battery system with BMS; I need, in any case, a little more complex system.

For these reasons, I thought about this solution.

[ranger58sb]

Originally Posted by anaif03

Thank you all for your precious feedback. I need to rebuild the electrical system from scratch because the past owner manipulated it so profoundly that it can be fixed. So I thought having only one system in place could be more accessible. Otherwise, I need to cable the 12V for lighting in each cabin plus 220v/110V for a socket.

On top of this, as many of your said TV and other appliance are cheaper and better.
I will have a lifepo4 battery system with BMS; I need, in any case, a little more complex system.

For these reasons, I thought about this solution.

We have a mix of 24VDC and low voltage AC lights (24VDC "bulbs") throughout. No clue why, can't find any advantage to that.

So I'm also in the "Why?" camp when it comes to lighting.

Feeding 120V outlets and appliances with an inverter can make sense. Frost-free fridges, TV/stereo stuff, microwave/convection oven, coffeemaker, etc. Even that depends, though. Ours is set up that way, but that's not a recommendation.

-Chris

[CaptTom]

One more reason: LED lights run on low-voltage DC internally anyway. Run everything you can on 12VDC. Cheaper, lighter and thinner wire, more reliable and safer implementation, no conversion or standby losses and one less point of failure in the system.

Appliances are another story. Most are only run briefly anyway, and aren't critical. Wire those for 120V for convenience. A 12/120V fridge is a good idea though. If you watch a lot of TV that might be another area where the extra cost of 12V is worth it.

[Chuck34]

You must have a pretty decent size boat to have 220v appliances. All I have ever had was 120v.

[team karst]

Quite a history on 220/230/240 volts. UK and continental Europe were 20 volts apart, settled on 230. A number of other countries at these levels also (homes and boats). A lot of the world has no 120v

[ChrisJHC]

Originally Posted by Chuck34

You must have a pretty decent size boat to have 220v appliances. All I have ever had was 120v.

Welcome to the world outside of (mostly) the Americas!

https://en.wikipedia.org/wiki/Mains_...ity_by_country

[CaptTom]

Originally Posted by ChrisJHC

Welcome to the world outside of (mostly) the Americas!

The OP mentioned 110VAC so I answered with that in mind. Obviously the same arguments apply whichever mains voltage we're discussing.

[jamhass]

Besides the already mentioned safety issues, one objection I have is overall electrical efficiency. Inverters do have parasitic loads, so for example, running the inverter to light a 120v (say) 20 watt lightbulb will inevitably take power power than running a 12v 20 watt bulb. Sure, the current is lower for the 120v bulb, but the power is higher due to inverter losses. Thus, the 12v approach results in somewhat reduced need to recharge the batteries.

We went the opposite direction in our boat, converting nearly everything to 12 v and were happy we did. Plus, a 12v boat really doesn't care if the shore power is US or EU -- the battery charger takes care of all that whereas many 120v (or 220v) loads/appliances do care -- often a LOT!