Full Boat Rewire

[impulsive19]

I've striped out the hull of my 57' ketch for a full re-fit. Having completed the engine, tranny, deck and hull fittings - electrical is next...


My question is this - as the 12v / 120v systems are contemplated -


Is it possible or even advisable to use 110v LED cabin lights only - powered by the 12v house batteries thru inversion - and skip the dual wiring at least for lighting ?


The boat is equipped with large single engine capable of supporting dual alternators - and has a 7.5kw generator.


Or should I go all 12v for LED lighting and skip all 110 fixtures ?

[Jubilee39]

The invertor will consume a small amount of power continously. If you are trying to conserve energy this could be a factor. There is a greater selection of lighting obviously in the 110 volt range. One consideration might be using 110 volt lights that use an external regulator and substitute a regulator that is powered from 12V

[tkeithlu]

There are now 12v LED lights to replicate every 110v lightbulb I can think of, and more. That means that you do not have to miss out on using a really attractive 110v fixture because you stuck with 12v DC wiring. The most obvious is the 110v pear shaped traditional light bulb. As an example. I use 12v DC LED bulbs in the daisy chain of ordinary hang-them-up trouble lights in my engine room. Here are some I use:

https://www.amazon.com/12V-Low-Volta...753039825&th=1

So, there is no impediment to your decorating with whatever fixtures you desire, while staying with the more efficient 12v system. As an added advantage, you reduce the number of light-up-your-life shocking experiences available to you. Just don't put a 12v LED bulb in a beautiful lamp and then plug it into a 110v socket....

[Spot]

I would also have the majority of the lights be 12VDC and get high quality LED bulbs that are 'quiet' as far as electromagnetic interference go (SuperbrightLEDs or Marinebeam). My old RV has a couple 'fancy' (1970's avant-garde) fixtures that are 110VAC converted to 12v with those 12v bulbs with the medium base. I would have a white/red switching fixture at the nav desk or companionway. I would not worry about PWM dimming the whole boat unless you wanted to make a task or mood light in a certain area.

[HeywoodJ]

I'm somewhat on the opposite side of the fence. There are some safety concerns with 110V around water, but if you accept those....

We run a Victron Phoenix 375VA inverter 24/7. Its no-load draw is 6W or 0.5A (@12V). In ECO mode the no-load is 1W (we don't use ECO). We run our household style refrigeration off the inverter. Because it is always on, we have started connecting other small loads when they come up. Have not (yet) connected lighting, but have considered it if/when we want to replace fixtures. So much more available in the household space, some of it suitable.

Yes, you take an efficiency hit. For us that is made up far more by the efficiency of the equipment we have connected.

[Discovery 15797]

Originally Posted by impulsive19

My question is this - as the 12v / 120v systems are contemplated -


Is it possible or even advisable to use 110v LED cabin lights only - powered by the 12v house batteries thru inversion - and skip the dual wiring at least for lighting ?


The boat is equipped with large single engine capable of supporting dual alternators - and has a 7.5kw generator.


Or should I go all 12v for LED lighting and skip all 110 fixtures ?

IMHO, the simple answer is no you should not use 110 fixtures for lighting at all.

Yes, high quality marine LED lights that don't emit RFi are expensive. but they last forever and have very low power consumption.

Running your inverter to power cabin lights will suck more energy than you think. Also, if you're thinking 110 LED lights, then essentially you are taking DC converting to AC and then converting back to DC!

Skip the 110 vac lighting fixtures but not outlets.

[impulsive19]

Ok - so the 12v's have it for cabin lighting...
but with all the new fancy electrical inversion equipment available - where does one get the most utility by using -for instance- a Mastervolt type charger/inverter (3000watt) for an investment of @ $1800 each or even doubling that type of equipment up and having 6000 inversion watts available?

[Joh.Ghurt]

Unrequited advice: If you do a full rewire consider going 24V or even 48V (if you believe in the future) instead of 12V. This will reduce the necessary cabling for most power hungry appliances like windlasses, fridges, etc.

Lighting can also be done via 24V (used for trucks and buses) and the few marine electronics needed can be fed via a 24-12 V DC-DC connector.

If I had to rewire, that's the way I'd go, although I haven't looked into it enough to decide whether 48V is a good choice yet.

[goboatingnow]

Originally Posted by Joh.Ghurt

Unrequited advice: If you do a full rewire consider going 24V or even 48V (if you believe in the future) instead of 12V. This will reduce the necessary cabling for most power hungry appliances like windlasses, fridges, etc.

Lighting can also be done via 24V (used for trucks and buses) and the few marine electronics needed can be fed via a 24-12 V DC-DC connector.

If I had to rewire, that's the way I'd go, although I haven't looked into it enough to decide whether 48V is a good choice yet.

ah yes 48V , and spend your life installing 48V to 12V dc dc convertors

[team karst]

I’d go 48v if and only if:
Windlass is 48; any thrusters are 48; air con is fed from 48 to 120 inverter, 48v bank is large enuf to not need genset at nite, 12v bank to feed small dc loads. Lots of ifs.

[JBP]

Originally Posted by Jubilee39

The invertor will consume a small amount of power continously.

110V LED fixtures/bulbs also loose a fair amount of power down converting the voltage back to LED levels, which is why they get warmer than 12V fixtures/bulbs.

Aside from the inefficiency though, I don't see any reason you couldn't. You'd still need 12V for marine specific stuff like radios/AIS/Autopilot/etc.