Tie in power inverter?

I'm not familiar with your specific trailer but that doesn't look like an inverter. The right side is a line-voltage breaker panel for your plugs and stuff, in the middle are your 12V fuses for lights, fans and controls and the left looks like the battery charger circuitry that charges your batteries when you're plugged in. An inverter of significant capacity would be fed with much larger cables from the batteries (probably 8 gauge at least).

I see a couple of issues here...

I don't see what your plan is for splicing into the 12VDC and 120VAC side of the Inverter.

You can tap the 12VDC by just paralleling the 4AWG cables. The problem for this is finding a suitable place to tap the 4AWG cable. It appears your 4AWG cables are trimmed and inserted into a LUG arrangement. You cannot double up on one of these LUGS. Some CONVERTERS have DUAL LUG connection points but I am not seeing anything like that inside the available connection points. You need to run 4AWG cables all the way to the NEW INVERTER.

The next area of concern is where to connect the 120VAC OUTPUT wiring. If your plan was to use the same 120VAC Receptacles for the items you want to have on emergency power then you have to install a switch or contactor that will select either the 120VAC power coming from the Distribution panel or coming from the Inverter. You cannot parallel these leads like you did on the 12VDC cables. It has to be selected from one of the two 120VAC sources. This is more complicated to do and is the big reason why alot of folks will just provide a drop cord arrangement coming from the INVERTER 120VAC and in order for you to use it you have to plug your 120VAC appliances into the emergency 120VAC receptacle.

This is what I did with my 600WATT Pure Sine Wave INVERTER. It is installed on the inside cabinet wall as close to the BATTERY BANK Selector switches using the ring terminal lugs to make my 12VDC connections. The INVERTER must also have a pretty heavy fuse block installed as well. This needs to be the same type of battery studs so that all 4AWG cabling uses the ring terminal ends for all 12VDC stud connections. With all of this in place then you can just plug in a HD 120VAC Extension cord into the PSW Inverter 120VAC receptacles and run this cord to the location of the 120VAC appliances you want to feed. Since there is usually two 120VAC receptacles on the Inverter I ran an extension cord to the home entertainment area and a second extension cord to the bedroom night table location. Using the Pure Sine Wave type Inverter I do not have to worry about what I plug into the emergency power receptacle.

This is a drawing I did up showing a typical install using the two Extension cords idea.


If you really want to Install a manual SELECTOR TYPE switch to use your existing 120VAC Receptacles then you could do something like this... Note All 120VAC connections are inside approved type Electrical Junction boxes.




These type of 120VAC selector switches are not cheap...

just some of my thoughts to give some additional ideas. Working with the 120VAC side of things has to be installed in a safe professional way...

This is my floorplan for my off-road POPUP setup showing where the Inverters and extension cord multi-outlets are located.


Roy Ken

This is a schematic that goes along with the 120VAC selector switch shown above... They wired in several different 120VAC appliances in addition to what you was wanting to do. This just shows what you need to do to allow the 120VAC receptacles to be used from the two different 120VAC sources (Distribution Panel or the Inverter). You will need to adapt this to your wiring of a couple of 120VAC receptacles. This drawing was for the whole Distribution Panel being selected between the Shore Power and Large sized Inverter. This is much more involved than what you are wanting to do... Just showing this to give you some ideas on what you will need to develop for your project. You will only need to switch a couple of 120VAC circuits - not six as shown here...



Roy

What I would do: Add a separate distribution panel for the loads you want to feed from the inverter. Add an automatic transfer switch set up so that priority is the feed from the existing converter breaker - that way if there is power from the post or the generator it is first priority, and the inverter power is only switched on if there is no power from post or gennie. I would add 12VDC cables directly to the batteries for the input side of the inverter. Next I would upgrade the 12/2 cable from the post and the generator input to the converter - 12 gauge is only rated to 20 amps but you have a 30 amp breaker, so your are overloaded for the wire size. Or install a 20 amp main breaker. Be aware that only permanent connections to the inverter are code compliant in a permanent install - connecting with a plug is not compliant (but everyone does it anyway).

Brian

Let me be more specific, the power inverter that I want to install would be mounted and accessible, next to the converter in the camper. I'll run 4 gauge power and ground directly to the batteries for the inverter. Then I'll make a cable from 12/2 with a normal 120V plug at one end, then tie it in somewhere to the utility panel that I showed a picture of. I have a Perko switch between the utility panel battery charger and the batteries, so once it's powered, it won't charge the batteries. I understand the disconnect switch, and will use one of those. I don't, however, want to get into automatic switching if it's a huge cost.

The only 12V power source in this camper thats accessible is inside a cabinet with the TV. There's not enough current there to power this inverter, hence adding one. I intend to trip the unneeded breakers when I power from the inverter that I wire in, so it won't have as much load on it. Another reason for this, is that the TV and receiver is plugged in inside the cabinet also. I really don't want to run an extension cord through the camper to power them.

SO you are going to pull the 120VAC leads that goes to the receptacle that the home entertainment items is plugged into and just connect that to the INVERTER. It will always be only connected to your INVERTER. You cannot jumper your 120VAC to this same connection along with the 120VAC that may be connected to shore power. It has to be one or the other ???

On the extension cord idea. I do not see my extension cord. It is totally hidden except where the multi-port receptacle is attached to either inside the cabinet or on the back of the table top. All of the cord per say is inside cabinets, behind walls or inside wiremold from LOWES. It just makes it easier as you don't have to pull 120VAC wiring out of the distribution panel.

I unplugged my home entertainment items and plugged into the extension cord and I just leave it that way. I am always running those items off the INVERTER.

There is another issue as well as some INVERTERS will not live well with your trailer GFCI receptacles. When you plug in it trips your GFCI circuits. My AIMS PSW 600WATT Inverter works ok with the GFCI in my trailer. This is another plus for running the extension cord idea.

These are all just my observations with my comments - just passing along what I had to deal with... Every situation is unique it seems.

Oh another issue perhaps - when you pull the 120VAC from the distribution panel breaker for the home entertainment items what else is being disconnected. My trailer has several 120VAC things on the same connection for the home entertainment items. They love to daisy change the 120VAC receptacles...

I'll get out of y'all hair - I'm probably being ignored anyway haha...

Roy Ken

jonyb wrote:
then tie it in somewhere to the utility panel that I showed a picture of.

And I guess that 'somewhere' is a breaker that feeds the TV outlet..?

I want to tie the inverter in to power all the breakers in the utility panel, not just the breaker that feeds the TV. That's why I'd trip all the extra breakers that are not needed.

The way my camper is set up there's no way I can hide an extension cord. The TV is in a wall mounted cabinet. On the other side of the wall is the bathroom, and the utility panel/inverter is past that bathroom. IF I plugged a cord in, the cabinet door wouldn't latch closed, and it would cross the path of 2 doors. People would trip over it going to the bathroom. And then it would only feed the TV. I want to power a receptacle for a circulation fan also.

In the picture, a 12/2 comes in on the bottom right corner feeding the terminal strips. That's where I "think" I can tie this in. I'll be the only one operating all of this, so I believe I can get by without a disconnect switch, or just unplug it and turn off the inverter when not in use.

You have the basic wiring plan correct but are missing the piece about the transfer switch. You should have either an inverter with it's own auto transfer switch or an independent transfer switch.

It might only take one instant, one time, to do some serious damage to the electrical devices in your rig if two power sources are online at one time. In your specific use, it may be easier to establish a subpanel with just the few circuits powered that you intend to use.

Transfer switch choices. In fact, I'd give the folks at Best Converter a call and ask them what they think.

RV electrical. There are many good ideas here about wiring and inverters.