110vac / Shore Power / Battery Combos

[Finding Id]

Being a newbie to a boat that actually has a full electrical system with shore power and goodies, I had a question that I am sure is probably common knowledge, but I've got no clue .

On my electrical panel, I have an option to turn on my 110 system that powers all of the electrical outlets on the boat. This switch only powers my outlets when I have the boat plugged in to shore power. It doesnt work at all when I am out sailing and have no shore power supply.

What I assume, is that theres some sort of power inverter somewhere that requires shore power to use the electrical outlets? I'd like to see if it is possible to hook up these outlets to the battery bank on the boat as well. Or could it be possible I am missing some sort of a switch somewhere that switches between battery/shore power? Or is it just that batteries lack sufficient power to allow usage of the 110 system?

I understand you dont want to run everything off of the batteries so as not to drain them, but it would be nice to be able to power cell phone chargers/laptops for short periods of time.

Does anyone have any suggestions?

I guess you might need to know more about the boat, it's a 1974 Columbia 34'

Thanks.

[S&S]

If there's an inverter, there'd be a breaker for it on the 12V panel. (or there should be). It may be easier to install a 12V outlet and get a car charger for your cell/laptop.

[GordMay]

Originally Posted by Finding Id

... What I assume, is that theres some sort of power inverter somewhere that requires shore power to use the electrical outlets? I'd like to see if it is possible to hook up these outlets to the battery bank on the boat as well...

An inverter runs off the batteries, and converts it to 120VAC. It doesn't require access to shore power.
WHY do you assume the boat HAS an inverter, that you have not yet found?

[Finding Id]

Originally Posted by GordMay

An inverter runs off the batteries, and converts it to 120VAC. It doesn't require access to shore power.
WHY do you assume the boat HAS an inverter, that you have not yet found?

Good point, guess I haven't really put that much logic into it. It would be a lack there of correct?

Theres a ton of nooks and crannies in this boat, and the electrical was redone by a PO, the majority of the electrical is kind of a mess, combination of extension cords, surge protectors, original wiring, and some sort of rewire for the cabin lights. Extremely confusing to decipher. Thats why I guess I was wondering how its "supposed" to work?

Do most boats have some sort of switch that allows them to run the electrical outlets off of the battery bank? Or is it typical to need to be plugged into shore power to run them?

Basically everything but the electrical outlets run off of the battery bank on my boat currently (when the 110 switch on the panel is off), yet when it's plugged in, and I turn the 110 switch on, everything automatically switches to shore power, and no longer draws from the battery bank.

[Pblais]

Inverters are not standard on most boats. What you really need to do is look at the panel and write it all down. Then see what all the switches control. Seems silly but it's your boat - who could say otherwise. It really helps you to know what everything is and at the highest level what things mean and how they work.

Good news. AT CF we as a whole know everything - except what is on your boat. We frown on members lurking about when you are not around. if you can do the basics of finding out what everything is in all the nook and crannies we can help. It's all new stuff to you and that is where all of us were and still are to some degree.

As far as nooks and crannies go we had a thread on stuff people found years alter that they never knew was there. We all have things found and lost on a boat as big or smaller than yours. It's a treasure hunt to be sure.

[Finding Id]

Originally Posted by Pblais

Inverters are not standard on most boats. What you really need to do is look at the panel and write it all down. Then see what all the switches control. Seems silly but it's your boat - who could say otherwise. It really helps you to know what everything is and at the highest level what things mean and how they work.

Good news. AT CF we as a whole know everything - except what is on your boat. We frown on members lurking about when you are not around. if you can do the basics of finding out what everything is in all the nook and crannies we can help. It's all new stuff to you and that is where all of us were and still are to some degree.

As far as nooks and crannies go we had a thread on stuff people found years alter that they never knew was there. We all have things found and lost on a boat as big or smaller than yours. It's a treasure hunt to be sure.

Maybe tonight or tomorrow, Ill take a bunch of photos to show you guys how odd some of the wiring is I've got the entire panel assessed as to how everything works, and what it controls, but don't understand how some of it "switches" things around. If that makes sense?

For instance. Everything runs off shore power when the 110 switch is on (lighting, electrical outlets, bilge pumps, water pressure, etc). When the 110 is switched off, the electrical outlets no longer function, yet everything else switches from the shore power and then runs off of the batteries. I guess I don't understand how that works. How does 1 switch cut off the power from the electrical outlets, and then switch everything to the battery bank? I guess I need to draw the circuit on paper so I can see it. Either that or disassemble the electrical panel and see how it's wired.

The other problem seems to be that some switches seem to operate nothing. Such as the blower switches. It could be that the blowers don't work too. I haven't looked at them.

Youre right though. I need to just trace all the wires around and see exactly whats up. Just so hard to do when everything seems so darn slapped together! Also, some areas I have no clue how to get into.

The good part is, while exploring a nook and cranny a bit ago I found a solar shower! Thats a bonus! Plus it doesnt run on electricity! Kind of funny how I can design a computer chip at work for a living, but the darn boat electrical just boggles my mind and is dauntingly scary! Im always worried about electrical fires and burning her down. Though, Im sure that might ease up a bit the longer I own the boat.

[redcobra]

Typically, the shore power goes to an AC double pole breaker. When SP is connected and the switch is on, the AC outlets function. The SP may also power a battery charger. However, I bet the lights, bilge pump, water pressure, etc runs off the batteries all the time as these are 12V devices.
Disconnect the batteries and I'll bet only the AC outlets work when the AC switch is on and nothing works when it is off and the batteries remain disconnected.

[Sunspot Baby]

So back to charging cell phones or laptops for a short period of time.

Catalogs are full of small inverters that plug into a 12v (cigarette type) outlet and can run 110 items.

For the laptop, I suggest you buy a power supply that plugs directly into 12v.

Likewise, most cell phones have car adapters that will run on 12v.

If you want to take the next step, you can buy and install a combination charger and inverter. We occasionally run power tools or a vacuum off ours. There is considerable battery drain when doing so. It powers our regular outlets.

Most low cost inverters are "square wave" and some 110v applications want full "sine wave."

[Sandero]

If you have an inverter, you'll probably need a transfer switch which allows you to select shore power to energize your 120v AC loads or the inverter which is connected to your 12v system.

On shore power you probably have, or should have a 120v AC shore power charger which charges you batts and allows you to use 12v loads, pumps, lighting etc. dockside.

You could have a dedicated system of 120v AC outlets without a transfer switch which operate on shore power and another for the inverter.

YOU DON'T want to have the inverter ON and connected to same 120v AC outlets which are being energized by shore connection AT THE SAME TIME.

[motion30]

this is easy,, look at your battery bank, follow any large cables that do not go to the starter if you have an inverter there it will be

[Masquerade]

I am not able to access shore power all that often but I have a few things on board that need 240 volt power which I run through small inverters. I have a few small ones rather than one big one, mainly for cost reasons but if one ceases to work then I can swap with another. What I will be purchasing is one of the newer smart battery chargers for when I can access shore power to charge the batteries. I don't really have a great demand for 240 volt (Australian) power as a rule. One of the best investments I did make was a small 1000 watt generator. It operates most small power tools, can be easily stowed, can also charge the batteries and is quiet. I pulled out some of the 240 volt wiring because it was installed by a definite hammer chewer. Good luck with your investigations.
Colin

[FrankZ]

Originally Posted by motion30

this is easy,, look at your battery bank, follow any large cables that do not go to the starter if you have an inverter there it will be

Good advice.. though one should take this with a grain of salt. You don't know what kind of tom foolery a PO has done (like wire a unit with 12AWG and somewhere attach that to the 6SAE). It might be confusing at times as you trace things. Tracing them out can require a ton of patience.. and some creative thinking to try and figure out why in the heck someone did things.

Logic may not help much at times.

[Jetexas]

I'm doing a lot of electrical research myself, and from the setups I've seen, the fuse panel usually has one bank for DC with all the switches fused and one bank for AC with all the switches on breakers.

The only link between the panels is usually a power converter that uses the shore power to charge the batteries. (The breaker switch and wires are there on mine, but while tracking down the reason the battery wasn't being charged despite getting 110 volts to the back of the breakers, I discovered there was no converter to be found in the boat. lol)

You don't want to wire all the outlets into the DC circuit on an inverter because most appliances like blenders, microwaves, etc. draw a lot of amps. It's going to take an expensive inverter, and it's going to drain your batteries fast.

You also don't particularly want to have the outlets wired into both the AC circuit and the DC circuit through an inverter because then you've got to be very careful what's switched on when - unless maybe you had it all on a three-way breaker switch or something - but it's just asking for disaster.

I'd suggest adding a new fused switch in the DC panel with a car type inverter with one AC outlet and a USB port. That way, no wires get crossed and everyone knows that's where you charge your phone.

Or you could just get a 12v outlet as someone else mentioned, and plug whatever inverter or car charger into that.

[Finding Id]

Wow, thanks for all the input! I did manage to find 2 12v's last night. One at the chart table, and another in the birth. I didnt have it in me to track wires though, so that may be tonight. I also found that theres a battery charger under the settee thats hooked up to the batteries when the 110 is on, which is why the battery bank isnt dropping when I have the lights and accessories on (this caused me to think they were switching back and forth since there was no voltage drop).

[Masquerade]

The other investment I suggest you make is in a good multimeter. To go with this I suggest you make up a couple of long leads with alligator clips you can use to extend the length of the leads on the multimeter. This way you can test each of the circuits individually and look for any voltage irregularities.

I am a great believer in going back to first principles. I know there are some who say that if it aint broke don't fix it but I believe that the boat is your safety machine and, if you can't work it out, rip it out and start all over again. On my first boat I tried working out some dubious (dodgey) circuits and waisted a lot of time. What I found was that the old wiring had been laid up in the fibreglass and that it was not adequately protected against corrosion so there were intermittent problems that were causing me to lose more hair than the aging process. So I just wore the expense and replaced everything and installed new conduit as well. The stuff I used was that used in computer networks. It looked neat and I could easily pull the cover off to put new stuff in and check things out. I have had to do a lot of this on my current boat and it is far more successful in the end than working with unknowns.
Colin