Question: plugging shore power cord directly into Inverter.

ghrost wrote:

MrWizard wrote:
you need batteries for the SOLAR aka to power your inverter...

I was just thinking easiest way was plugging shore power into a inverter.. but I'm leaning toward the 12v ideas from you guys, thanks. Easy doesn't mean better so i rather do it right.

Get rid of your converter and get an inverter/charger with an automatic transfer switch builtin. Samlex makes one, but I am sure others make them also.

They are not cheap, but they are so easy to install with all connection in one location ! Shore power goes directly into the inverter/charge (hence no need for a converter) to charge your batteries. Your DC distribution panel is wired directly to the battery via a large fuse.

AC power for the entire RV comes from the inverter/charger. If shore power is available, it is used. It it is not available, the inverter turns on.

There is a connection for the output of your solar charge controller.

The larger units (listed a 2 AC inputs) have a separate input for a generator and with addition wiring can actually start the generator if the load requires it !

2oldman wrote:

BFL13 wrote:
The inverter then runs off those batteries and powers all 120v items, including the converter. The converter can then make your 12v for all those systems. .

Wouldn't it be much simpler to run the 12v off the batteries?

Most likely would be. Depends how much trouble it is to get it all wired back up with a good converter, location of the battery bank, etc.

I did my test on the notion of having the batteries in a separate trailer with the inverter and solar panels on that. Could do that with 24 or 48 even. Then plug in the RV and use its converter as the 12v DC supply. Was some discussion at the time how to do up one of those power supply cargo trailers that some MHs tow.

BFL13 wrote:
The inverter then runs off those batteries and powers all 120v items, including the converter. The converter can then make your 12v for all those systems. .

Wouldn't it be much simpler to run the 12v off the batteries?

I tried that for fun and it does work, but the converter will cause the inverter to draw about 6 amps from the batteries. So the solar will have to make up for that, as well as whatever other amp draw there is by the inverter running other 120v things.

You do need a solar controller between the batteries and the panels.

The inverter then runs off those batteries and powers all 120v items, including the converter. The converter can then make your 12v for all those systems. There is no "loop" converter/inverter to worry about as such.

It depends very much on how much sun you get and how much DC you use for how much of a battery bank runs the inverter etc etc, but it is doable in certain scenarios.

Best to have a portable generator and a good battery charger in case not enough sunshine sometimes.

Your converter in that old rig can run the 12v things, but might need a battery to act as a filter for its dirty DC, but perhaps not--it depends if any of the 12v things need clean DC. Also the converter will be a poor battery charger for any house battery you do have.

You could use a new type deck mount converter as your battery charger to go with the portable generator. That converter could also be used instead of your original one to do things either way--house battery or not.

You will be missing any alternator charging of the house battery if there is any set-up for that in that rig.

If it has a generator, note that many rigs have it so the generator needs the house battery for starting it.

if you need 120v power for things like the TV, PC, phone charging

yes plug into the inverter

but no need to do double conversions, too power items that should be powered directly from the batteries

Just because you can plug in does not mean it is the best solution.

DrewE wrote:

time2roll wrote:

Also verify your inverter is made to connect to an RV electric distribution system. Some do not like the 120v ground connected to the 12v side of the battery supplying power.

Ground or neutral?

The 120V neutral should not be connected to the chassis ground (and thus not to the 12V ground) in a motorhome when the inverter is running; they would only be connected if plugged into shore power, at the shore power's service entrance, or if running a (typically built-in) generator where neutral is tied to ground.

I would be surprised if most inverters care where the 120V ground is connected to at all. If they did, using them to power any 120V grounded tool while the inverter is sitting in, say, a pickup truck bed would be dicey at best, as setting the tool down in the bed would connect 120V ground to the negative battery terminal. Surely running tools and such from a vehicle electric system is one of the major applications of an inverter.

There are plenty that will say not to tie the inverter to any electrical distribution system.
I have read plenty of posts where the inverter would not work unless the battery is isolated.

I am not an expert on every inverter... just saying read the manual before you click and buy. Especially if searching lowest price.

MrWizard wrote:
you need batteries for the SOLAR aka to power your inverter

connect those batteries to your house circuits, you should have house battery power, your fridge, water pump , furnace, lights... need 12v power

solar to inverter to converter to get 12v for those items, is wasteful and silly

I was just thinking easiest way was plugging shore power into a inverter.. but I'm leaning toward the 12v ideas from you guys, thanks. Easy doesn't mean better so i rather do it right.

you need batteries for the SOLAR aka to power your inverter

connect those batteries to your house circuits, you should have house battery power, your fridge, water pump , furnace, lights... need 12v power

solar to inverter to converter to get 12v for those items, is wasteful and silly

time2roll wrote:

Also verify your inverter is made to connect to an RV electric distribution system. Some do not like the 120v ground connected to the 12v side of the battery supplying power.

Ground or neutral?

The 120V neutral should not be connected to the chassis ground (and thus not to the 12V ground) in a motorhome when the inverter is running; they would only be connected if plugged into shore power, at the shore power's service entrance, or if running a (typically built-in) generator where neutral is tied to ground.

I would be surprised if most inverters care where the 120V ground is connected to at all. If they did, using them to power any 120V grounded tool while the inverter is sitting in, say, a pickup truck bed would be dicey at best, as setting the tool down in the bed would connect 120V ground to the negative battery terminal. Surely running tools and such from a vehicle electric system is one of the major applications of an inverter.