Installing an Inverter

[Balou]

Hi,
We have a 2002 Winnebago Journey that does not have the whole coach inverter option.

I would like to know if this option can be installed, what size inverter would be needed and can I use the existing power transfer switch?

[BFlinn181]

The 'can' part of your question can easily be answered. Yes. You need to determine what you plan to run on inverter. I wouldn't recommend the A/C, as they require too much battery storage capacity. Add up the other loads you contemplate, add batteries to store necessary power, then size the inverter to do the job. You also should think about what you wish to power and if they all will play nice with MSW or need a PSW version. Most inverters have a built-in circuit breaker and transfer switch, so they aren't wired through the transfer switch but after it. If you're increasing the number of batteries, you might just replace your present converter/charger with an appropriately sized inverter/charger to handle 120v and 12v charging needs.

[Skip426]

My coach has a small inverter for the front TV and two outlets , I did look into an up grade, but found the price and work involved .
All the whole house inverter set ups I've seen , are wired in after the transfer switch , but have isolated circuit breakers , so items like the roof A/C are not powered.
These inverters , usually 2,000 or 2,500 watt , require at least 4 golf cart 6 volt
house batteries to operate for any length of time ( 6 batteries would be better).
JMHO: Depending on your intended use, the conversion might not be worth the $$$.
Myself , I do not boondock for any length of time , and when I do spend a night without power I choose a location where running the gen set is an option.

[Balou]

Thanks guys, I will be buying a PSW inverter.

I'm looking to power is my cpap, frig and computer. The frig draws 3 amps on AC according to my power center display. I figure a 1000 watt should be good for my needs?

I also have the small inverter in the compartment above the windshield for the front and back tv's.

How do I wire the new inverter in to power only the items I want powered?

[LookAtUSNow]

I'm no expert but I've read a few similar post and will share this with you. Don't consider only running amps you need to look at start up amps which are more. Your refer sounds like it may be an rv fridge, no motor, but electric motors draw more amps on start.

[BFlinn181]

Originally Posted by LookAtUSNow

I'm no expert but I've read a few similar post and will share this with you. Don't consider only running amps you need to look at start up amps which are more. Your refer sounds like it may be an rv fridge, no motor, but electric motors draw more amps on start.

Starting amps for an electric motor may be more, but then most inverters have two ratings, one for sustained output, the second for peak output, which would cover starting amps. If it's a modern scroll compressor type fridge, it probably works on 12v via a built in inverter.

Inverters only work at about 80% efficiency. For your CPAP machine and computer I'd look for 12v power adaptors rather than waste energy converting from 12v DC to 120v AC, then have the appliance convert it back to 12v or so DC.

If planning to install an inverter, you might size it to handle microwave and coffee maker, too. In our RV, that's what we miss without 120v power.

[Balou]

Yes, the frig is an RV type that will run on propane also. My CPAP has a humidifier so it needs 120vac.

I like the idea of saving my propane for cooking and heating.

The way it is now I must run my generator all night just for my CPAP. I figured if someone here knew how to wire in an inverter for my frig and wall plugs, I'd be set.
I have separate breakers in the breaker box for these things now.

[Sweetbriar]

The absorption fridge uses very little propane, as compared to the furnace, but can quickly consume a battery bank with the watts the AC heating element requires. 3 amps of 120 VAC is 360 watts. Using 12 VDC to make the 360 watts will require 30 amps of 12VDC power plus there are line looses and inverter internal consumption that will increase the number. As such I would leave it as configured. Using 12VDC from a battery to make heat is very power and capacity consuming.

A 1000 to 2000 watt invertor configured to automatically switch in to power specific outlets should do what your are asking. Complexity and cost of the set up will be dependent on how may circuits (a circuit would be one breaker feeding multiple outlets) you wish to energize AND total potential power demands. If you are considering using a hair drying, the microwave oven and a coffee pot all at the same time you might run into problems with capacity of the inverter. Not unusual to find owners with multiple invertors and a very large battery bank to power everything except the air conditioner and water heater.

Option 1 - If you are looking to power up one or two circuits the easiest configuration would be to add individual transfer relays after the circuit breakers for the circuits you want to energize.

Option 2 - If you have three or more circuits then adding a second breaker panel and transfer switch dedicated to the circuits (and removing the same from the original panel) might be a better solution. Many rigs are factory built this way as Skip426 posted.

I went with option 1 for my coach.

[Skip426]

Originally Posted by Balou

Yes, the frig is an RV type that will run on propane also. My CPAP has a humidifier so it needs 120vac.

Have you checked with the CPAP manufacturer ?
DW's CPAP , has humidifier and there was a 12 volt adapter available.
Even with the humidifier 12 volt draw is less than 7.5 amps.
Much easier to get 12 volts to the bedside than rewire the 120 volt outlets to inverter.

[charles tuit]

Originally Posted by Balou

Hi,
We have a 2002 Winnebago Journey that does not have the whole coach inverter option.

I would like to know if this option can be installed, what size inverter would be needed and can I use the existing power transfer switch?

I also have a 02 Journey that had a small inverter for the entertainment system. I chose to go the full upgrade to a Xantrex 458 MSW 2000 watt inverter/charger . I had a sub panel installed with the circuits that I wanted to be powered by it. I chose NOT to power the hot water heater, air cond/heat pump and engine heater with the inverter. If they are used your batteries will discharge rapidly.

I have 4 each golf cart (GC2) batteries powering the inverter. If I had to do it again I would go with a pure sine wave, 2000 watt inverter charger. Your batteries will like the 3/4 stage charger over the charger you have and your appliances will like the pure sine wave inverter. The Xantrex has a automatic transfer switch when 110 volts are applied.

Hope this helps with your decision.

[Balou]

Thanks for all the replies.

I have another option to present to you.

Can I install this inverter and just plug my shore line into it when needed?

2000 WATT PURE SINE POWER INVERTER 12 VDC TO 120 VAC ETL LISTED – The Inverter Store

[PJStough]

Originally Posted by Balou

Thanks for all the replies.

I have another option to present to you.

Can I install this inverter and just plug my shore line into it when needed?

2000 WATT PURE SINE POWER INVERTER 12 VDC TO 120 VAC ETL LISTED – The Inverter Store

Yes, you can. I did this for a while before using Xantrex automatic transfer switches to power the outlets I wanted powered. If you go the shore line plugged into the inverter route, make sure you have the circuits for the air conditioners and the onboard charger/converter shut off. Also, dont try to use the electric water heater.

[Balou]

Thanks PJStough,

The transfer switch in the coach would still work right? In other words, I don't need to unplug the shore line from the inverter if I start the genset to run the microwave.
Right?