inverter installation, suggestions?

[billgallivan]

Dw and I are going boondocking this summer and will need a/c power.
my 97 Itasca doesn't have an inverter so I bought a 4000 watt to install.
my older, not fancy mh has a 30a plug that I either plug into the genny, or to the pole at the campground, never had inverter.
I have a total of 5 125ah agm batteries to run this thing , 2 under the stairs and 3 I added under the dinette seat, but I am unsure of the best location to mount the inverter, I want it as close the batteries as possible I know, I am thinking under the dinette seat, and run 10g ac wire to an outlet next to the genny outlet, and just move the plug to it when needed, I also plan on adding a 120v relay to the inverter output to break the input to the converter when on battery power.
where do most people mount their inverters in these things, this is our first class a , and my old class c didn't have 1 either.
any suggestions?

[nothermark]

The closer to the batteries the better. Either under the dinette or in the compartment below.

Seems like a lot of work and a lot of expense for a few hours of A/C. I'd just run the generator.

[Soppy]

You will need large cables 4/0 from the inverter to the batteries. The 4000 watt inverter will draw about 350 amps at full load. It should be mounted as close to the batteries as possible. With tour battery bank, you will have 7.5 kw/hrs available. For good battery life , they should only be discharged 50% giving 3.75 kw/hrs of power. An A/C unit will draw at least 1.5kw/hrs. So you will have about 2 hrs of air conditioning use. You will then have to run the generator 3 to 4 hrs to fully charge the battery bank.

[cruzbill]

You don't want to hear this but: the 4k inverter is way too big. Inverters are for a few outlets at a time, maybe the microwave, not designed to 'plug in' your 30a power cord. 4k watts = 333a at 12v. That's BIG wire (and fuse) between battery bank and inverter. Lotsa amps + undersized wire=fire hazard.

Idle current on your inverter is likely so much that you will draw your batteries down without doing any real work.

Make a list of what you want 120vac for, each item, figure out the watts required and est usage per day in min. Now what do you NEED to operate at the same time?
That will tell you how big an inverter you need.

An inverter is not a panacea-It won't run your A/C all day.

https://www.gonewiththewynns.com/off...r-conditioning
And with all the amps in your battery bank, you are playing with fire.

Sorry to be the bearer of bad news. Don't shoot the piano player.

[aether_one]

I think the OP meant 120 VAC when he said A/C power, not the Air Conditioner.

[cruzbill]

What I was talking about was when the OP said he wants to 'move the plug' to the inverter. Has to mean his 30a shore power cord. OP needs to define what AC loads (the air conditioner load is a non-starter on an inverter) he NEEDS to run.

[BigBillSD]

Originally Posted by tfryman

I think the OP meant 120 VAC when he said A/C power, not the Air Conditioner.

When I read it I assumed he meant Air Conditioning too.

I replaced my 2k MSW watt Inverter with a 2.8k PSW Inverter. Looking back, I probably could have just done another 2k PSW but I like having the extra capacity if needed. I left in the 300 amp fuse. Using my Trimetric http://amzn.to/2FAf45g I see is pulls 1 amp with no load. I even put a shutoff switch in front of the Micro to shut it off overnight so only whats actually needed runs while we are sleeping.. SageTV DVR recording shows, Network etc.

-Bill

[Soppy]

Just to clarify things ... A/C = Air Conditioner AC = Alternating Current (120v power).
Don't want to give out the wrong info.

[325BH]

Actually there isn’t any established initialism to separate the two. Both are used interchangeably for each.

Context is important, however when discussing both in the same conversation, using the full words is helpful if context isn’t enough.

Defining the shorthand upfront is also helpful.

[garbonz]

Read the OP post again and think that he wants 120 volt alternating current power throughout the rig, but doesn't mention air conditioning so that may be an unknown. He knows enough to have extra batteries, and even knows to switch out the converter, so this is not his first rodeo. Several issues include the separation of the batteries which may be a problem, length and gauge of wire, and exactly what he is going to power.

The answer to the question "where to put the inverter" has been answered.

[twinboat]

I mounted mine under the dinette seat. The batteries are under it, in a compartment, so I drilled a hole thru the floor, to keep the cables short.

Just make sure it doesn't get to hot under there. My under seat space is open to the large under sink area. Its been running fine for 4 years.

When you lock out the converter, you may want to lock out the fridge too, if its gas/electric. Gas/electric fridges are power hogs on 120 volts. Then there is the water heater, if its 120 volts. That's another power eater.

When I installed mine, I used an external inverter transfer switch and only powered the 2 breakers that supplied the outlets.

Installing a transfer switch on lines coming " out " of the breaker panel, skips all the stuff that I didn't want to power.

[billgallivan]

i have no intention of trying to run air conditoner, but a point was made about fridge,,
does absorption fridge usr alot of ac power?
i have gas only water heater, and all I am planning to run is the fridge, tv, coffee pot, and microwave, also to charge laptop etc.
of course coffee pot amd microwave will only see limited use.
thankyou for all the input so far, but, should i run fridge on gas, or do i have enough power to get me thru a few days without genny?

[vsheetz]

Originally Posted by billgallivan

i have no intention of trying to run air conditoner, but a point was made about fridge,,
does absorption fridge usr alot of ac power?
i have gas only water heater, and all I am planning to run is the fridge, tv, coffee pot, and microwave, also to charge laptop etc.
of course coffee pot amd microwave will only see limited use.
thankyou for all the input so far, but, should i run fridge on gas, or do i have enough power to get me thru a few days without genny?

I had a whole house inverter setup as you are doing on a previous coach - just plugged the shore power cord into a 2300w inverter. Worked fine.

An RV refrigerator takes a lot of 120vac power - and very little propane. Switch it to propane.

Use propane for refrigerator and water heater. Disable the converter as you know to avoid a charging loop. Don't inadvertently switch on the air conditioning - can be easy to do on some combo hvac control panels.

[aether_one]

An RV fridge will take 400 - 500 watts when running on 120 VAC. As others have said, when boondocking always run the fridge on propane.