How to hook up Inverter to Breaker panel

[zoshia]

Hello all,

I have a very small trailer that only has two lights and one outlet. These items are currently wired to a 110volt break panel which then gets hooked up to shore power when available.

However I would like to set up a battery system for when I’m off the grid. I plan to purchase a 12volt deep cycle battery. I choose this over two 6volt batteries as it's cheaper. I will then connect this battery to a 300 or 400 watts power inverter. Please note we will not be plugging anything in that draws too much power into the outlet. We are trying to do this at low cost. Especially being we only have two lights and one outlet.

So my question is, how do I connect the inverter to the breaker panel to power my two lights and outlet? Do I plug in an appliance cord to the inverter, cut off the outlet end and wire it to the breaker panel?

In addition, my breaker panel has two lines coming out of it only one of them is being used (for the existing lights/outlet). Do I use this other line to connect it to the inverter?

My next question is what are our options in charging the battery? I know we can get an inverter charger but those are a few hundred bucks... Or we can get a convertor but that takes up room and are also pricey from what I have seen on the net. How do I know if my cars battery will charge up the trailer battery when hooked up? It's a four pole system.


If you have any other better ideas on any of this please let me know as well. Like I said were trying to do this on the cheap.


Thank you!

PS: Attached is a crude drawing of our breaker panel.

[Bob Miller]

Here are three of many ideas for you to ponder.
1. Install a couple of 12 volt LED fixtures so you don't have to power the 120VAC fixtures from the inverter. Cost, about $35 for two. Then install a seperate outlet for the inverter, another $15, BUT your battery will last a lot longer with the LED lights.
2. Install a Double pole double throw switch. The center terminals will go to your existing A/C power box. One side will go to your inverter output, the other to your shore power cable. There is a P&S switch just for this. About $50.00
3. Install a regular outlet box near where your shore cable is stored. Hard wire the outlet box to the output of your inverter. Plug the shore cable into the outlet box when you want to run on the inverter. About $15
Hard Lesson #27: When you do it "on the cheap" ,you usually end up doing it several times

[floyd]

Originally Posted by zoshia

Hello all,

I have a very small trailer that only has two lights and one outlet. These items are currently wired to a 110volt break panel which then gets hooked up to shore power when available.

However I would like to set up a battery system for when I’m off the grid. I plan to purchase a 12volt deep cycle battery. I choose this over two 6volt batteries as it's cheaper. I will then connect this battery to a 300 or 400 watts power inverter. Please note we will not be plugging anything in that draws too much power into the outlet. We are trying to do this at low cost. Especially being we only have two lights and one outlet.

So my question is, how do I connect the inverter to the breaker panel to power my two lights and outlet? Do I plug in an appliance cord to the inverter, cut off the outlet end and wire it to the breaker panel?

In addition, my breaker panel has two lines coming out of it only one of them is being used (for the existing lights/outlet). Do I use this other line to connect it to the inverter?

My next question is what are our options in charging the battery? I know we can get an inverter charger but those are a few hundred bucks... Or we can get a convertor but that takes up room and are also pricey from what I have seen on the net. How do I know if my cars battery will charge up the trailer battery when hooked up? It's a four pole system.


If you have any other better ideas on any of this please let me know as well. Like I said were trying to do this on the cheap.


Thank you!

PS: Attached is a crude drawing of our breaker panel.

First you must define terms...
A converter normally produces 12V DC when supplied with 110V AC
(110V AC in.... 12V DC out)

An inverter normally produces 110V AC when supplied with 12V DC
(12V DC in.... 110V AC out)

If you have a 15A cord to normally supply shore power, and an inverter attached to the battery, you could then simply plug the "shore power"cord into the inverter when needed and use the inverter instead of shore power .

[Darwin Maring]

Bob has hit the nail on the head. I don't think you could do any better than that and it will be SAFE.

[rabbit]

I'd prefer Bob's solution #1 as the 12vdc LEDs aren't power-hungry and you want not just the hookup for illumination FROM 12volt source but also a type of illumination that can be supported by a limited 12 volt source (battery) for a reasonable time. I've heard that going from 12vdc to 120vac isn't very "efficient." The normative setup for on/off grid is a converter (to charge battery from shore power) and dual distribution panel for both ac and dc. However, since you don't have a converter, I guess you're allowed to think about which is faucet and which drain with an inverter. You will have to charge that battery some way some time (soon) and that would demand a battery charger or converter.

jack

[steve dunham]

Originally Posted by Bob Miller

Here are three of many ideas for you to ponder.
1. Install a couple of 12 volt LED fixtures so you don't have to power the 120VAC fixtures from the inverter. Cost, about $35 for two. Then install a seperate outlet for the inverter, another $15, BUT your battery will last a lot longer with the LED lights.
2. Install a Double pole double throw switch. The center terminals will go to your existing A/C power box. One side will go to your inverter output, the other to your shore power cable. There is a P&S switch just for this. About $50.00
3. Install a regular outlet box near where your shore cable is stored. Hard wire the outlet box to the output of your inverter. Plug the shore cable into the outlet box when you want to run on the inverter. About $15
Hard Lesson #27: When you do it "on the cheap" ,you usually end up doing it several times

#2 is an excellent idea ! You must have a way to isolate the inverter power from shore power .You will never get the two sine waves to sync

[cpaharley2008]

He still needs a converter, otherwise his battery will discharge. I'd go the converter route and install 12v lights and that way the converter will charge his battery when hooked up to 120v, other wise he needs to but a battery charger to charge the battery from 120v in order to convert back to 12v for what??
Keep it simple and cost effective, a converter can be had for less than $200 and you will be set then.

[Bob Miller]

Forgot to Answer the 2nd question
With a 4 pin connector you don't have a line to charge the coach battery and will either have to provide that via a seperate wire pair (Battery + and a ground), connectors and circuit breaker, or get a seperate charger to charge the battery when plugged in.
As mentioned, a new power chassis/converter is the best bet. Google about the Progressive Dynamics PD 4045. I have installed many of them and they provide everything... A modern a.c panel, up to 45 amps of DC with 10 fused circuits and a 3 stage smart charger system that will take excellent care of your battery. PD 4045's are available on eBay for about $140 + Shipping.

[mmeyer]

Agree with Bob, Steve, rabbit et al.
Might add that when you are off the grid and just running on Battery. I would wire either a large ( high Amp) battery disconnect switch or at least a 40-50 amp relay on the hot side of the inverter. The Inverter sucks a little power whether you are using it or not and over 24 hours makes a dent in your reserve. I noticed this the last time we were out on the Outer Banks of NC even with my solar I could tell a difference the one day I forgot to shut off the inverter.
At 400 watts you will draw about 33+ amps full load so the switch or relay needs to be robust as well as the wires feeding the inverter. The relays or switches are readily available on Amazon or your favorite establishment. Relays are around $10 and there is a key switch for less than $20.
My 2 cents.
Michael J.

[cpaharley2008]

Me thinks if he installs a converter, he will not need an inverter. Everything will be 12v except for any plugs.

[rabbit]

Well, there's ingenious thinking and then there's bad form and just about the baddest bad form of all is the infamous double-male insinuation of 12 volt joice into an AC receptable chain. ONLY try this at home!!!

jack