DC to AC help

[kfp673]

Hello All. I know it has been discussed a million times but I'm struggling to find posts that start with "step 1". Feel free to simply point me to a post if you know if one.

We started doing a lit more boondocking 2 years ago. We upgraded to dual portable generators, added more water storage, and upgraded the single 12V battery to a pair of 6V. The 6V upgrade was huge and allows us much more time with out the generators. I might add to that but the next thing I'd like to do is power some AC devices such as coffee maker and TV off the battery. When I search, most of the inverters have AC plugs directly on them but I would like ours hard wired in. Ideally we would like to have any AC plug have the ability to run off the battery with an inverter before the panel but I'm not sure how to do that or which (relatively affordable) inverter to go with. If I learn from your replies that picking 2 or 3 AC outlets is easier then I am fine with that as well, but I still want it hardwired with either an auto switch over or manual switch but where it feels to the user as if you had AC power to the trailer. Auto switchover would be preferred.

Any help is appreciated and thanks in advance

[pianotuna]

valhalla360 wrote:

pianotuna wrote:

valhalla360 wrote:

pianotuna wrote:
Hi kfp,

I ran a thirty amp cord from the inverter to an outlet. I cut the 30 foot cord and added a new male end.

Commonly referred to as a "Dead Man's Cord" or "Suicide Cord". Goes against pretty much every electrical code.

Be very careful following this advice. Even if you are aware and understand the risks, someone else may not be aware and get themselves killed.

You misunderstood. I added a dedicated outlet powered by the inverter. Then I plug the shore power cord into the outlet.

All of my modifications are up to code. It costs almost no extra money to do it safely and correctly.

If you are replacing the 30amp male end with a 15/20amp male end, so you can plug directly into the female outlet on the inverter without an adapter, that's fine.

A cord with 2 male ends (which is what your original post appeared to imply as there was no indication of changing the type/amp rating of male end), is used by some people, so they can just connect the inverter to a convenient outlet near the inverter and back feed power to the AC system. This is dangerous.

What part of dedicated female outlet do you not understand? The inverter powers the outlet. The RV is plugged into the added outlet.


In my particular case the outlet happens to be hard wired to the inverter, using 3 #10 wire rated for 30 amps.

The inverter is 3000 watts and the no load voltage happens to be 123. That means a wire rated for 24 amps would be adequate. However I chose to use 80% load which means using wire rated for 30 amps.

[valhalla360]

pianotuna wrote:

valhalla360 wrote:

pianotuna wrote:
Hi kfp,

I ran a thirty amp cord from the inverter to an outlet. I cut the 30 foot cord and added a new male end.

Commonly referred to as a "Dead Man's Cord" or "Suicide Cord". Goes against pretty much every electrical code.

Be very careful following this advice. Even if you are aware and understand the risks, someone else may not be aware and get themselves killed.

You misunderstood. I added a dedicated outlet powered by the inverter. Then I plug the shore power cord into the outlet.

All of my modifications are up to code. It costs almost no extra money to do it safely and correctly.

If you are replacing the 30amp male end with a 15/20amp male end, so you can plug directly into the female outlet on the inverter without an adapter, that's fine.

A cord with 2 male ends (which is what your original post appeared to imply as there was no indication of changing the type/amp rating of male end), is used by some people, so they can just connect the inverter to a convenient outlet near the inverter and back feed power to the AC system. This is dangerous.

[philh]

I did something interesting on my new 5th wheel

It came generator ready, but I chose to not get the gen. I put a 50a plug on the front of the trailer, and tied it into the transfer box. I then mounted a 2200w inverter in the front, tied to s dual 100a LiFePO4 battery bank and attached a 30a cord to it, and added a 50a plug. I turn on the inverter, plug in the connector, and I have 120v throughout the entire trailer. I also added a switch to turn off the charger too.

[pianotuna]

valhalla360 wrote:

pianotuna wrote:
Hi kfp,

I ran a thirty amp cord from the inverter to an outlet. I cut the 30 foot cord and added a new male end.

Commonly referred to as a "Dead Man's Cord" or "Suicide Cord". Goes against pretty much every electrical code.

Be very careful following this advice. Even if you are aware and understand the risks, someone else may not be aware and get themselves killed.

You misunderstood. I added a dedicated outlet powered by the inverter. Then I plug the shore power cord into the outlet.

All of my modifications are up to code. It costs almost no extra money to do it safely and correctly.

[ewarnerusa]

kfp673 wrote:
Thanks! I like the simplicity of your method of simply plugging the shore power cable into the inverter, but doesn't that cause the batteries to try to charge themselves? With onboard chargers in the camper any time I have AC plugged in the charger is on. Does this cause a problem?

Edit- Actually, I see you dedicated a breaker to the onboard charger so you can isolate and turn that off. Found a youtube video of this exact install. I guess the only downside is having to change the shore power cord back and forth from inverter to generator throughout the day.

Thanks again

You got it, converter must be off when doing it this way. I personally have my converter off by default and rely on solar. Converter would be a backup charging method which would then trigger the need to hit the switch.

When we camp in summer heat, then the generator comes along for running the air conditioner. But otherwise, no swapping going on and we're plugged into the inverter for the whole stay.

[valhalla360]

pianotuna wrote:
Hi kfp,

I ran a thirty amp cord from the inverter to an outlet. I cut the 30 foot cord and added a new male end.

Commonly referred to as a "Dead Man's Cord" or "Suicide Cord". Goes against pretty much every electrical code.

Be very careful following this advice. Even if you are aware and understand the risks, someone else may not be aware and get themselves killed.

[kfp673]

ewarnerusa wrote:

kfp673 wrote:


Curious, where did you mount the inverter to make in convenient for your shore power cord? Also, what size inverter do you run and off what size cable from the battery system? Thanks!

Front pass through storage of a travel trailer. Battery connection is about 5' of 2/0 gauge.1500 watt pure sine wave inverter

Thanks! I like the simplicity of your method of simply plugging the shore power cable into the inverter, but doesn't that cause the batteries to try to charge themselves? With onboard chargers in the camper any time I have AC plugged in the charger is on. Does this cause a problem?

Edit- Actually, I see you dedicated a breaker to the onboard charger so you can isolate and turn that off. Found a youtube video of this exact install. I guess the only downside is having to change the shore power cord back and forth from inverter to generator throughout the day.

Thanks again

[ewarnerusa]

kfp673 wrote:


Curious, where did you mount the inverter to make in convenient for your shore power cord? Also, what size inverter do you run and off what size cable from the battery system? Thanks!

Front pass through storage of a travel trailer. Battery connection is about 5' of 2/0 gauge.1500 watt pure sine wave inverter

[pianotuna]

Hi kfp,

I ran a thirty amp cord from the inverter to an outlet. I cut the 30 foot cord and added a new male end.

[kfp673]

ewarnerusa wrote:
My technique is similar to pianotuna's. When boondocking I do the following:
1. Fridge and water heater on propane
2. Disconnect converter. I isolated my converter's power supply to its own AC breaker that I switch off. I also have air conditioner, electric water heater, and microwave breakers switched off to avoid accidentally running them (too much load for my battery system)
3. I plug my camper's shore power cable into the inverter's AC outlet.
4. Turn on inverter, now all outlets are live in the camper.

Curious, where did you mount the inverter to make in convenient for your shore power cord? Also, what size inverter do you run and off what size cable from the battery system? Thanks!

[ewarnerusa]

My technique is similar to pianotuna's. When boondocking I do the following:
1. Fridge and water heater on propane
2. Disconnect converter. I isolated my converter's power supply to its own AC breaker that I switch off. I also have air conditioner, electric water heater, and microwave breakers switched off to avoid accidentally running them (too much load for my battery system)
3. I plug my camper's shore power cable into the inverter's AC outlet.
4. Turn on inverter, now all outlets are live in the camper.

[kfp673]

Great feedback everyone. I'm busy reading all of this and appreciate the help!

[steveh27]

In my Class B Xplorer I have a 400 watt inverter for the tv. I hard wired it to the 2 LiFePo4 batteries. I tried just plugging it into the cig lighter 12 v outlet, but that has a very long circuitous way to the batteries and the tv will not work with a little battery drain. So I wired it direct in a much shorter route and have an on/off switch.

The sat tv box and tv just plug into it. Works well. Obviously this low power inverter will not run the microwave or coffee maker.

[pianotuna]

Here is how my system works:

1. set fridge to propane
2. disconnect converter
3. power all outlets from a hybrid inverter charger.

To operate high draw items such as a microwave at least 4 six volt batteries may be best.

My microwave draws 170 to 180 amps @ 12 volts.

Size the inverter at 125% of the largest load intended to be used.