Want to add inverter to power all 110v receptacles

[completelyhis]

Greetings,

My system is equipped with shoreline and generator that will simultaneously charge the house battery and provide power to the 110v system. It is equipped with a power CONVERTER that supplies 12v dc when AC is provided from either one of those.

I'd like to add a power INVERTER so that my 110v AC receptacles and appliances can be operated from the house battery as well. I'm clueless as to how that would be integrated into the system. There are schematics that came with the van (1993 Dodge Sportsmobile) attached. They show an installation of the generator, and the inverter, but not both.

Does anyone have any advice?

Thanks

Ian

 

[B and C]

I originally wanted to do what you are wanting, but gave it up. Here is why.

This will be really tough to do. Your GFCI outlets, converter (for the 12V stuff) and your charger for the house battery are all on the same 120V circuit.

Injecting the inverter into the 120V stream would be easy. Get another auto transfer switch (like your generator uses) and wire it in anywhere between the generator and circuit breaker.

The real problem lies with your battery charger. Without getting it out of the circuit, you would have a feedback loop. Battery powering inverter - inverter powering battery charger = disaster.

Far easier to put the inverter close to the battery and use an extension cord.

I run two smaller inverters (less conversion losses). I have one in my entertainment center for the satellite dish and another one in the kitchen cabinet I use for a 4 cup coffee pot when I can't run the generator (I like drip coffee but don't want to babysit a pourover when I am not awake yet). Much easier setup and it won't burn down the house if I forget to flip a switch somewhere. Most everything else is native 12V powered including my crock pot. I use the generator for the heavy hitters, toaster, 12 cup coffee pot, Cuisinart griddle and convection/microwave. The generator only needs to run a short time for any of these.

YMMV

 

[tx2sturgis]

Two basic ways to do this:

Install a manual transfer switch that operates manually (of course), or with a relay that automatically switches when shore power or generator power is available or becomes unavailable.

or

Remove your existing converter, and install an inverter/charger.

As mentioned above, it is far easier to install a seperate inverter to power a few appliances as needed.

 

[B and C]

Remove your existing converter, and install an inverter/charger.

I might have to look into this if the inverter part is not too big and the charger is big enough.  I hate wasting anymore of that solar energy than I have to

 

[B and C]

I am going to stay with what I have. The 700 watt Aims with selectable charging amps (iirc 20 and 50) on Amazon looked promising until it comes to the battery charger part. From the reviews it is not a smart charger. Specs only list float voltage.

 

[tx2sturgis]

Here's one....they have others too...


http://www.samlexamerica.com/products/ProductDetail.aspx?pid=572

 

[B and C]

Wow, 2200 watts is their small one! 750 is the max I need for my little coffee pot.
This would be a lot of money to spend to take care of a couple of small items I don't use very often.
Thx for looking.

 

[John61CT]

Just wire 12V, then a small inverter for specific appliances to plug into.

 

[Trebor English]

A transfer switch is a pair of two position switches, technically, double pole double throw.  One switch is used for the hot wire, black, and the other switch is used for the neutral wire, white.  The pair of switches are one piece always switching together.  To do what you want you need two of them.  

Connect the shore power and the generator to the first transfer switch.  The output of the first transfer switch is used to power the battery charger, 12 volt converter, and loads that are too heavy for the inverter.  That's where I would connect my electric space heater.  

The second transfer switch gets one input from the inverter and the other input from the output of the first transfer switch.  This is the circuit that you want to feed all the convenience outlets all over your van.  

Both of the transfer switches can be manual regular switches.  If you want automatic that is easy to do too.  An automatic transfer switch  is a relay.  That's just a switch with a coil, an electromagnet, to switch it.  For the first transfer switch you can wire the coil to shore power.  When there is shore power the generator is disconnected and the shore power is connected.  This way you can start and test the generator without interfering with the shore power.  To use the generator, start it, let it warm up, unplug the shore power, the relay coil gets no power, the switch goes to the other position, the generator position.  

For the second transfer switch power the relay coil with the generator / shore power transfer switch output.  You don't want to use the inverter to power the coil.  Only have the relay coil powered when you have generator or shore power.  Battery is too precious to use on a relay coil if it is avoidable.  

The devil is in the details.  If you alredy have stuff wired together some may need to be separated.  If you have the converter plugged into an outlet that you want powered by the inverter you can't have that without unplugging it when necessary.  Reconnecting the converter to the first transfer switch may require running a wire.  

Another detail is that the inverter must be very close to the battery, just inches away.  That means you need a wire to get the 120 to the second transfer switch.  The switch needs to be somewhere too.  The automatic transfer switches are bigger than a light switch.  Think six inch cube.  

You can have the second switch automatic and the first one manual.  The first transfer switch can even be as simple as unplugging the van from shore power and plugging the cord into the generator.

 

[John61CT]

> the inverter must be very close to the battery, just inches away

Huh? As long as robust AWG wiring suitable for the max load sized for minimal voltage drop, can be as far away as you like.

Just like any DC load consumer.

 

[John61CT]

Another way to go, for those designing from scratch who are off-grid most of the time.

All mains power outlets come off inverter only.

Mains power connection to the van only powers the charger (RV "converter") and nothing else.

That connection goes into genny, or grid power as appropriate.

Downside is a little inefficiency, but only when connected to grid power, when it doesn't matter as much.

 

[Chernobylite]

I wired my rig to be a "whole house" inverter system. When not on shore power the cord gets fed back to an outlet that switches between my generator and inverter with the transfer switch being inverter dominant. That way only one transfer switch is needed.

As was previously stated it's important the converter is disabled to prevent feedback when running whole house. That can be done with a switch or by turning off the converter's CB if it's on its own circuit. Or it can be disabled automatically by wiring the 110 volt side through a set of NC relay contacts with the relay coil sampling the inverter output. Mine is that way. Works well.

 

[John TF]

1st things 1st , you have to come up with a plan , a plan is based on what tools are available to accomplish work , powering devices , and with what , not just alternative energy , but its called a site survey - what loads do you have & what source , or combinations of sources are available .
Then maybe 2nd , what is your budget ?
Next long range plan ?
Then its mostly just math , so some corrections , your outlets are 120vac - not 110 .
Generally speaking , do not buy from Amazon , that almost automatically gets you going down wrong road - price only , and if you compare pricing , too many times - Amazon costs more , and does not have available QUALITY options .
One of the issue's with setting up mobile systems , is that they are not a sizable market that can produce the numbers - for competition - giving a balance of quality & price , as an example solar panels - the smaller the panel the higher the price per-watt , maybe even more so , inverters with an exception , you can find small / cheap / chineeze inverters , but you can not find small interactive inverters - by that I mean something that is going to be part of a system - inverter , charger - that will inter-grate with a programable charger & monitoring system , transfer-switch , etc.
A generally a systems block diagram should be - multiple sources of power - transfer switch - loads this includes storage .
Part of your issue is , adding inverter - and not eliminating the converter , it kinda can be done , but is complicated & redundant .
Too long , need to get back to - what is your budget & long range plan .

 

[completelyhis]

After reading everyone's very helpful comments (I love this forum!) I've decided that the cost/benefit analysis indicates it's not worth it to power ALL the outlets via the inverter. I'll just add two new outlets that are inverter powered. One of them will be near a zip-strip that I power the microwave through, and it's near the kitchen, so I easily switch the zip strip from 120v generator/shore to the inverter.

Thank you all for being awesome!

Ian

 

[John61CT]

KISS works well

 

[ZoNiE]

I did this in a TT by disconnecting the wire for the 110VAC outlets from the breaker and wiring a cord plug on it. I then wired an outlet to the breaker. The outlet and the 1000 watt inverter were next to each other. When I needed the inverter, I plugged the cord into one of its outlets, when I was on shore or genset power, I connected the cord to the outlet wired to the breaker. It kept the systems separate, and the inverter does NOT power anything else in the Trailer, not even the charger. These inverters are also not rated for permanent 110V wiring, so this was a cheap and easy solution that you could not screw up since you can only plug the thing into one source at a time.