Off grid 120 volt

[Ffergie]

Hello all
We have our Cedar Creek 33LCDTS 5th wheel set up on a lakeshore and, due to local regs, have to be off-grid. We have managed for the past few years but this year we have decided to get internet set up which will require 120 volts. Our current setup is 450 watts of solar feeding 4xTrojan 6V set up in series. Our electrical needs thus far have been very meager on 12 volts and we have had no issues. I have picked up a Renology 1000 watt pure sine inverter to use in the trailer for the internet hub. All that to say, I believe that the OEM charger/converter feeds the panel 120 volts through a 3 pronged plug that is plugged into the back of the panel (??), so...is there any reason that I couldn't unplug the charger/converter and plug the Renology inverter into that plug? That would get me 120 volts to the panel, and therefore to the outlet I need and prevent a potential "double-feed" of 120 volts from the charger/converter if/when I start the generator. Hopefully, this makes a bit of sense to someone. Thanks in advance/ Great group!!

[Flybob]

You may want to look carefully as most Internet equipment actually runs on 12V provided by a wall wart plugged in to 120VAC.

[Ffergie]

Thanks, Bob. I didn't even think of that but I would require 120 volts for the TV anyway.

[eric1514]

Suicide cord? Be very, very careful with that cord between the inverter and the outlet. Personally, I would come in the side if the box with the outlet with some romex.

[KMP44]

If you are going to alternate between the generator and the inverter, the way to go is to add a transfer switch.

Your converter is a single circuit in your 120V panel, fed from the main power inlet. It doesn't feed the panel - the panel feeds it and converts the 120 volts to 12 volts. When using an inverter you want the converter disabled so its not trying to convert the 120 back to 12V.

There are a few different ways to to achieve what you are trying to do, and it depends on how manual/automated you want things to be. A transfer switch when setup right (usually with a sub-panel) is more involved but will be easy to operate and insure you don't overload the inverter. Just back feeding into your main panel with a 1000W inverter could create problems on several fronts.

[Half Ton Heavy]

Just make sure the inverter is ETL Compliant or UL compliant if you are going to tie into the rv electrical system. Doesn’t have to be certified, just compliant. Cheap inverters often are not. If it is not, it will not work, BTDT, and the ground for 120 volt is not the same as chassis ground and will not let the inverter operate. If the inverter has a transfer switch, it will by default be compliant.

[mnoland30]

12v TVs are available. It is more efficient to run things on 12v because the inverter is only around 90% efficient. It is also more effecient to have the inverter close to the wattage you are actually using. Running a 1000 watt inverter to power a 100w load isn't very efficient. You have enough solar and battery so efficiency probably won't matter.

[Comanchecreek]

I do my Crusader fifth wheel the easy way. I plug the 110 inlet cord into my inverter. I turn the converter off at the breaker, and I turn my Norcold two way to gas only. All 110 outlets are then hot. I have a 2000 watt pure sine wave inverter. I have a remote on/off for the inverter which allows us to turn it off preventing battery loss to the parasitic draw. All lights, heat, pump, etc. are 12 volt so don't need the inverter unless we want to run the TV, or the Microwave, or the Instant Pot. I have portable solar and lithium batts. Rarely even need a generator.
Forgot to add that AC is not happening with this setup.

[awellis3]

Originally Posted by Ffergie

... I would require 120 volts for the TV anyway.

Not if you bought one of these for the TV. https://www.amazon.com/APINEE-Primiu...25&sr=8-5&th=1

[p_miles]

I agree with awellis3, we have a small inverter to power the TV and a small media server, the inverter is totally isolated from all other 115vac, and the distribution panel.

[jimmoore13]

I think you may be approaching this backwards...and making things too complex.

Many inverters come with built in transfer switches...which means that the inverter connects to the shore power converter panel and it connects to the battery.

When shore power (e.g. the generator) is available, the inverter takes its input power from the 120 volt supply and simply passes shore power through the inverter's output circuits. When 120 volt power disappears, the inverter draws from the battery bank.

Since a 1000 watt inverter is NOT going to power your whole coach, and since 4 x 6 volt GC-2s won't power your whole coach for very long, there's no reason to try to kluge up some system in which you're using the inverter to run other 120 volt loads in your coach. Locate the small inverter somewhere conveninent to your modem/router and TV...and where it's convenient to feed it with a 120 volt line from your panel and 12 volts from your battery bank. Oversize the wire.

1000 watts = 84 amps at 12 volts.

You'd probably be wise to go with 2 AWG wire for your connection to the battery if you are running any distance at all. For a small margin of error, use 100 amps to calculate wire gauge. This will minimize losses in the connecting wire. This will be the most challenging part of the installation unless you keep the iverter very close to the batteries and distribute power from the inverter using a 120 volt dedicated circuit. In that case, 14/2 household wire (what's all through your coach for 120 volt circuits) can carry the power from the inverter to whatever location suits you. 14/2 can handle far more than 1000 watts...about 9 amps at 120 volts.

Your inverter will have at least two outlets...for internet and TV, but you can use a surge protector to add more outlets...say you need one for a modem and one for a router...plus the TV. You could also feed two 120 volt circuits so long as you don't forget the ultimate source is only 1000 watts and 4 GC-2s.

If you choose to run wire underneath the coach...the easiest path...use conduit to protect your wire from rodents. PVC or steel will work. Rodents like to chew insulation. Conduit is cheap and easy insurance to protect your wire, and it simplifies installation.

This would make a safe, semi-permanent installation with none of the shenanigans you appear to describe in your OP (frankly, I didn't fully understand the plan).

Best of luck...and as others said, there are many 12 volt devices out there, including TVs. Eliminating the inefficiencies of the inverter would make sense. Apply your inverter and wire budget to 12 volt devices.

[Flybob]

As suggested a small stand alone inverter is easiest and least expensive. Jut remember when running anything off an inverter, for each 120VAC amp you use you will be using 10 12VDC amps.