I decided I would like to have 120 AC available in my motorhome when I am not on shore power without running the generator. I bought a 2500 Watt inverter on line and a 50 amp automatic transfer switch. Installing the inverter and the transfer switch became complicated due to space considerations.I decided I could install just the inverter but I wanted to make absolutely certain I did not connect the inverter and shore power or generator at the same time. I know that would not be a happy event. But I wanted the inverter to power outlets inside the MH. I needed a way to wire the inverter into the AC system of the MH that would be fool proof. That is why the automatic transfer switch seemed necessary.I have an epiphany at 3:00 an. Just install the inverter in the compartment with the 50 amp shore power cord. Use a 50 to 30 amp adapter and 30 to 20 amp adapter to connect the shore power cord to the inverter whenever I disconnect the shore power. That way I cannot connect the shore power and the inverter at the same. The automatic transfer switch already in the MH will insure that the generator will not connect when the inverter is providing AC.I am returning the new automatic transfer switch I purchased for this installation and saving $150.

If you are connected to shore power why you you need your inverter?Are you confusing inverters and converters?

Many of us do simply add a female RV outlet and then power that from the inverter.Which inverter did you purchase?

Just be sure to install your inverter close to your batteries to keep the 12 volt DC lines short. Then you can run a 12 AWG power cord to your 50 amp plug. You can buy a 50 amp - 15 amp adapter.

One consideration when plugging the shore power cord into the inverter is to turn off the 110 breaker for the converter/charger. If this is not done, the converter will attempt to charge the batteries that supply the inverter. This loop will either use excessive energy at a minimum or trip the inverter. We have labeled our 110 breakers for the converter charger and air conditioning and turn them off whenever plugging into the inverter. Works perfectly. Also may wish to avoid using the microwave.(Highly recommend a pure sine wave inverter when doing this.)

Installing an inverter in my Winndbago Journey | Good Sam Community

18 Replies

newizu
Explorer
Oct 27, 2020
Thank you all so much. you are real savers.
time2roll
Nomad
Oct 23, 2020
MAIN-needs to be on
AC-best to have this off
MICRO & W/H is interesting. Must have a load shed device. OK to be off but if you want to use the M/W it is best to set the W/H to propane only.
GFCI-generally you will want this on.
RECEPTS-yes you want this on too.
CONVERTER-off

The only question is where does the fridge get 120v power. Need to switch fridge to propane only unless by luck it is on the converter branch circuit.

Once you have a road map you may want to print it so if a non technical person wants to use the inverter the sequence is very simple.
newizu
Explorer
Oct 23, 2020
Thanks for your reply. My converter has several switches.
1-MAIN
2-AC
3-Micro & water heater
4-GFIC
5-RECEPTS
6-Converter
Should I turn off just the converter or any other switches.
My unit is a 2007 Four Winds Hurricane model 30Q
Once again. Thank you.
pianotuna
Nomad III
Oct 22, 2020
newizu,

Here is one wiring path for inverters for whole house.

battery bank-->inverter-->shore power plug

The converter breaker needs to be turned off.

The fridge should be set to propane.

Having a second bank for just the inverter leads to less total power available.

btw BFL13 just did some real life testing on SiO2 batteries and the results are quite encouraging.
time2roll
Nomad
Oct 22, 2020
newizu wrote:
This question is for Tropical36. I am interested in doing what you described you have done to connect inverter as shore power. Would it help if I were to disconnect power bank from main setup and use it as a stand-alone power bank to power the inverter?
Yes and no.

I assume you mean battery bank when you say "power bank"

Yes if you had a separate battery dedicated to the inverter you would not have to worry about the converter creating a power loop that drains the single battery.

No it may not save you much because the inverter powering the converter would still be charging the existing house battery potentially using a lot of power. Then you still need a way to charge the second battery dedicated to the inverter.

In the end I don't think this simplifies things. I don't recommend it.
tropical36
Explorer
Oct 22, 2020
newizu wrote:
This question is for Tropical36. I am interested in doing what you described you have done to connect inverter as shore power. Would it help if I were to disconnect power bank from main setup and use it as a stand-alone power bank to power the inverter?

Not really understanding the question here.
What are you referring to as the ....power bank... and are you perhaps talking about your house batteries?
What do you mean by the main setup?
All I was saying is that you might just plug your shore power cord into the inverter's 120vac output when you want to use it. Again, you must first open every non essential circuit breaker, when doing so or risk depleting your house batteries in short order. As for what you can keep, it will depend on the size of the inverter.
If you only want to operate a couple of things and the inverter is only 1000watts or less, it's not all that hard to run a couple of dedicated outlets here and there, like I did in our old gas coach and be done with it, as another option.
newizu
Explorer
Oct 22, 2020
This question is for Tropical36. I am interested in doing what you described you have done to connect inverter as shore power. Would it help if I were to disconnect power bank from main setup and use it as a stand-alone power bank to power the inverter?
pianotuna
Nomad III
Sep 13, 2020
consider that when using the inverter you wish to save as much power as possible. Having it power a relay may use about 12 watts.

If, on the other hand, you have shore power pull the relay closed, you save that 12 watts, when on the inverter. On shore power 12 watts is nothing. On battery power it is a lot.
tropical36
Explorer
Sep 13, 2020
warrenjo46 wrote:
EV2 wrote:
One consideration when plugging the shore power cord into the inverter is to turn off the 110 breaker for the converter/charger. If this is not done, the converter will attempt to charge the batteries that supply the inverter. This loop will either use excessive energy at a minimum or trip the inverter. We have labeled our 110 breakers for the converter charger and air conditioning and turn them off whenever plugging into the inverter. Works perfectly. Also may wish to avoid using the microwave.
(Highly recommend a pure sine wave inverter when doing this.)

Yes I did purchase a pure sine wave inverter (2500W).

I will install a normally closed relay in the power to the converter that will be energized to open when the inverter is turned on. That will prevent the converter from trying to charge the batteries with power drawn from the batteries.

My only problem with this plan is "where is the converter?"

After looking at several wiring diagrams and schematics I discovered that the converter is located under the refrigerator behind the grill that looks like the cold air return for the furnace. Since motorhomes are very compact manufacturers need to tuck devices into unexpected places.

With most of the newer coaches and not so new, the converter and inverter are compacted into one unit and usually in an outside bay near the batteries.
warrenjo46
Explorer
Sep 13, 2020
EV2 wrote:
One consideration when plugging the shore power cord into the inverter is to turn off the 110 breaker for the converter/charger. If this is not done, the converter will attempt to charge the batteries that supply the inverter. This loop will either use excessive energy at a minimum or trip the inverter. We have labeled our 110 breakers for the converter charger and air conditioning and turn them off whenever plugging into the inverter. Works perfectly. Also may wish to avoid using the microwave.
(Highly recommend a pure sine wave inverter when doing this.)

Yes I did purchase a pure sine wave inverter (2500W).

I will install a normally closed relay in the power to the converter that will be energized to open when the inverter is turned on. That will prevent the converter from trying to charge the batteries with power drawn from the batteries.

My only problem with this plan is "where is the converter?"

After looking at several wiring diagrams and schematics I discovered that the converter is located under the refrigerator behind the grill that looks like the cold air return for the furnace. Since motorhomes are very compact manufacturers need to tuck devices into unexpected places.