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cucamelsmd15 · 10-30-2013, 11:39 AM

Currently, this is how my RV (a Forest River FR3) is wired. Note that it doesnt have an auto transfer switch, it has a 30A output receptacle in the basement that you plug the cord into after disconnecting from shore power.

This is how Im proposing to change for the installation of a Xantrex (or similar) pure sine wave inverter.

Now, a few things that I know will get mentioned:

Yes, I realize I will have to unplug the converter/charger every time. I dont mind since Im already there (plug for converter is in the same bay).
Yes, I realize this will power every 120V AC circuit in the RV, including the AC. No, I dont intend to try running the AC off the inverter, this is mainly for the TV/DVD/outlet power while rolling down the road.
Yes, I realize I could replace the converter/charger with a converter/charger/inverter. I already have a Progressive Dynamics PD9280, which according to my research is a pretty good charger already, so Id like to keep it.
Yes, I realize an auto transfer switch would handle the plugging/unplugging for me. No, I dont wish to deal with one, Ive had more than one fail and its always a headache.

Otherwise, what issues do I need to address? I have an empty bay right next to the batteries in the MH, so the run of DC cabling and fuse will be ~3ft. From there, I intend to hard wire the 120V AC output to a NEMA 30TT plug that Ill put in the back bay next to the generator plug and label as "inverter".

Thoughts?

Scarab0088 · 10-30-2013, 12:00 PM

Your design is simple and should work well.

I use an aftermarket inverter in the same fashion, except I "turn-off" the converter/charger when on inverter power (converter charger is hard wired - there's no outlet).

Just for discussion - as you describe and per the inverter's instructions, keep the 12VDC cables short...the 110VAC cord can be as long as needed. This is because 12VDC voltage drop is impacted by longer cables more than 110VAC.

Best luck

Clay L · 10-30-2013, 12:12 PM

I also have to plug my shore power plug into a receptacle in the service bay to use the generator and do not have a transfer switch.
I did something similar to what you are proposing except I did use a transfer switch I installed behind the breaker panel. When the inverter is on the output is switched to the main input breakers. This feeds all of the motor home 120 vac circuits.
Before I turn the inverter on I open the breakers for the converter/refrigerator (same breaker) and the two ACs.

I would have used a sub panel so no breakers would have to opened but I did not have enough room.

Rocky Larson · 10-30-2013, 12:30 PM

That is pretty much how I am wired. I also have to plug the main 50 amp cord into the line coming from the inverter with adapters. This powers all outlets but of course with limited amp. A note posted in several key locations reminds me to take the converter off line. I do have a "Stand By" switch that came with the inverter that I mounted inside the coach to take it off line if need be.

wa8yxm · 10-30-2013, 05:48 PM

Well your design left me with some questions and concerns.

Is that inverter also a converter? If so change as follows.

(30 amp inlet)===========Everything else

(30 in)------Inverter-----Everything else (Disconect power to existing converter)

IN fact mark the circuit breakers for the converter, water heater, Air conditioner(s) and fridge with orange paint.. TURN them off when using the inverter.

And that's abouit all there is to it save leave the water heater and air conditioners off. and lock the fridge on gas.

Alternate

Leave everyting as is up to the main 120 volt breaker box

Install 20 amp breaker in box and feed it to the inverter/converter

Install second box and move selected loads to it

Feed it with the inverter.

NOTE; inverter/charger units have built in transfer switches.

If your inverter is a stand alone. (inverter only, no charger). Hook up more or less as you designed (Additional 30 amp outlet in power bay) and do not forget to DISABLE the converter.

Scarab0088 · 10-30-2013, 06:21 PM

Quote:

Originally Posted by wa8yxm

Well your design left me with some questions and concerns...Is that inverter also a converter?

IN fact mark the circuit breakers for the converter, water heater, Air conditioner(s) and fridge with orange paint.. TURN them off when using the inverter.

And that's abouit all there is to it save leave the water heater and air conditioners off. and lock the fridge on gas.

Marking the 110VAC breakers of the items not wanted and turning them off is a great idea.

The OP said he's adding an inverter and keeping (and unplugging) the PD9280 Converter/Charger.

I only have to kill the AirCon...have no 110AC in the water heater and the Microwave runs on the inverter perfectly.

QUESTION - Why lock the 'fridge on to gas? With the proper sized inverter, the 'fridge can stay on auto - default to 110VAC and save LP.

Safe travels

vsheetz · 10-30-2013, 08:07 PM

I am setup for inverter powering the whole coach, as you are proposing. Works well. I have a $10 wireless remote switch in the AC line cord to my converter - converter is mounted under the refrigerator. My 2300w MSW inverter has a wireless remote on/off switch as well. My shore power cord is typically plugged into the inverter unless I am at a CG and connected to a power pedestal.

As most inverters have a small current draw even when turned off, I have a disconnect switch in the positive wire from the battery to the inverter, used should I really be tying to minimize power draw on the batteries.

I typically run my Norcold 1200 refrigerator on gas rather than electric when on the inverter as it's a pretty healthy power draw, if I am going to have the inverter turned on for any amount of time.

I also have multiple point of use small 150w inverters inside the coach - one for the TV/DVD, another for computer area, etc. This more power efficient than using a single larger inverter.

My four Trogan 105 batteries are charged by 600w of solar panels.

cucamelsmd15 · 10-31-2013, 05:56 AM

Quote:

Originally Posted by Scarab0088

Marking the 110VAC breakers of the items not wanted and turning them off is a great idea.

The OP said he's adding an inverter and keeping (and unplugging) the PD9280 Converter/Charger.

I only have to kill the AirCon...have no 110AC in the water heater and the Microwave runs on the inverter perfectly.

QUESTION - Why lock the 'fridge on to gas? With the proper sized inverter, the 'fridge can stay on auto - default to 110VAC and save LP.

Safe travels

I'm pretty much in the same boat. Microwave should be fine, all my breakers are marked (including the coverter /charger), and my water heater is propane only.

Id set the fridge to gas because it only uses a small amount, and the batteries will last longer. My Dometic is an AC/gas only, and while i do t know the exact numbers for draw, I cant imagine it would be small just knowing how the cooling process works for it.

The downside to flipping breakers, and one of the reasons I probably wouldnt, is because the breaker panel is inaccessible in the bedroom with the slide in.