installing a 3000 watt inverter

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Well-known member
Mar 28, 2006
I would like to install a 3000 watt inverter in my recently purchased used 30 ' fiver. The unit is a Jazz built by Thor. It came equipped with a 120V to 12V converter/battery charger. The literature that came with the trailer says the unit includes an automatic switch that activates when shore power/gen is connected. I would like to set the inverter up so it power all the 120V circuits except the AC, Microwave and refrig. I would also like to install an auto switch so when I turn on the inverter it by-passes the shore/gen power.
Is this a major project and expense or something a do it yourself er should be able to handle and is there some reference material available ??

In addition I just installed 4 golf cart batteries and in the future will be looking for solar panels to help keep the batteries charged. Is there a simple/ inexpensive monitoring system available so I can keep from running the batteries too low ??? and how about recommendations on size of the solar panels.  ???

appreciate any help

You can wire the inverter to power selected circuits but it may require an additional load center for those breakers.? The transfer switch that the docs talk about is to switch between shore and generator power automatically.? It is unrelated to an inverter.? I would NOT wire the inverter to bypass shore power.? Inverters contain a transfer switch that passes the shore (or generator) power through to the output if available, and powers the output circuit from the inverter if not.? Don't try to wire it any differently.

You can run a microwave from the inverter for short cycles.  I would also exclude the hot water heater from the inverter power as well as the A/C and refrigerator.  In general, any applicance that draws more than a few 100W for any length of time should not be powered from an inverter.  That's what generators are for.

To power a 3000W inverter will require at least 6 golf cart size batteries.? It will also contain a suitable charger so you can get rid of the present converter.? Get a good monitor panel for the inverter and it will tell you everything you need to know about the state of your batteries.

It will take a lot of solar panels and sunlight to keep that many batteries charged if you really want to power a 3000W inverter.? Unless you use very little electricity you'll need a generator to keep the batteries charged, and if that's the case, you don't need a 3000W inverter.? Tell us what your needs are in more detail and we can perhaps give you some better, and cheaper, solutions.
I would NOT wire the inverter to bypass shore power.  Inverters contain a transfer switch that passes the shore (or generator) power through to the output if available, and powers the output circuit from the inverter if not.  Don't try to wire it any differently.

Not totally true - some inverters have built in transfer switches and some do not. Some have chargers and some do not. All depends on what you want and how much you spend.

You must wire the inverter such that the inverter never attempts to power the same outlet as is already powered by shore power or genset. To put it another way, any given outlet or device must be powered from only one AC voltage source at a time. Failure to do so will generally result is damage to the voltage source and/or the powered devices because of mismatch in grounds and frequency.  You can try to do thius manually, but sooner or later somebody will turn on the inverter while the genset is running (or vice versa) and who knows what may happen.

Yes, you can find inverters without transfer switches and chargers, but in the large sizes we're discussing, it's more the rule.? With the size battery bank needed to power a 3000W inverter, the existing converter just won't handle the charging chores so it would be foolish to buy an 3000W inverter without a 3 stage charger, and I don't know of any in that size that don't have the transfer switch.? When you're on shore power or generator you want that to power everthing and not the inverter.

If the RV isn't wired for 50A service, I wouldn't recommend a 3000W inverter/charger anyway.
the primary need for 120 V is my wife's 2 sewing / embroidery machines and associated equipment ( light, laptop, printer } and stereo, DVD. In the evening the TV and VCR  that should take care of it. the sewing machines are 300 watts each and she said she will be running both at the same time.
I doubt she can sew on both machines at the same time :)  I would install a smaller inverter, perhaps 1000W, that would be capable of powering all those devices.  Check out for a selection of products.  The Pro Series is designed for just such applications, but does not contain a charger so you may have to replace your converter if it isn't capable of charging the 4 golf cart batteries.  The Freedom series inverter/chargers are another option.
Ned said:
I doubt she can sew on both machines at the same time :) 


You haven't seen the new embroidery machines. They run on auto-pilot. Computer controlled. Note he said embroidery machines and associated equipment LAPTOP.  ;D
So I've been informed by Lorna.  Where's the skill? :)
This is getting deeper by the minute. I identified my converter as a MAGNETEK 6300 series. Checking google it sounds like an inexpensive unit with a "dumb" charger. Checking prices on inverters I find units with out transfer switches and chargers, modified sine are relative inexpensive. And then of course from wife/brothers " he's over engineering the problem again "  So the latest thought is to purchase a 1500 watt unit, no transfer switch / charger and install a single circuit for a power bar to feed my wife's sewing sweat shop and then consider  installing  an upgraded converter / charger. By the buy the trailer is wired for 30 A service

comments ???
Simpler is usually better :)  With 30A service, you are best to go with the 1500W inverter, but you may need to upgrade the converter/charger to keep those 4 golf cart batteries charged.  I would get an inverter/charger and scrap the converter.  You really need a 3 stage charger for those batteries.
You've been leading a sheltered life, Ned.  ;)  Technology has made all sorts of equipment options available and you aren't restricted to a Prosine or Heart any longer.  Take a look at the Xantrex Xpower, for example. 3 kilowatts and no transfer switch or charger.  Lots of similar units available, many for far less money.  I have a 2 KW standalone inverter myself and a 3 KW is now less than I paid for 2 KW 4 years ago.

And don't sell converter chargers short either. I have a 90 amp Iota with 3-stage charging. Progressive Dynamics make similar units and many trailers and some motorhomes now come equipped with them..
I was referring to his converter, it probably can't handle the charging needs of his new 6V golf cart battery bank,  Rather than upgrade the converter AND add an inverter, I would replace the converter with a combination inverter/charger.  My life is far from sheltered, as you know, and there are lots of choices, true, but most of them are under the Xantrex label :)
please clarify for me. If I install a new inverter with a charger won't I still need a converter to go from 120 V to 12 V. ??
No, the charger charges the batteries and your batteries supply the 12VDC.  The charger in the typical inverter/charger is a much better charger than the converters.

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