My inverter choice

[bevans6]

Well, i think I have made my choice of inverter to run my roof-top AC while on the road.  Go Power 3000 watt pure sine inverter, quite simple but seems a good choice.

http://www.invertersrus.com/gp-sw3000-24.html

Made overseas, but to the specification of Carmanah Technologies, a publicly traded Canadian technology company based out of British Columbia.  The units are widely used in commercial vehicles, in fact my local distributor is an upfitter of EMS vehicles and specializes in mobile power and air conditioning installations.  Kind of exactly what I am doing, which is nice.  And it is so nice to talk to a guy who knows exactly what you are asking, and knows the answer instantly!  The unit has my key wants - UL approval (although not shown in the manual, the 2000W and 3000W pure sine inverters do carry UL approval), a proper direct tie in with GFCI protection for AC distribution, remote control, and a high surge capability with actually fairly reasonable efficiency, up to 92% at 1/3 load, which is about where I will be running it 90% of the time.  So it's powerful enough to run my AC, efficient enough to run my small loads while dry camping, has the needed approvals, is designed for mobile use so it has a sleep mode, and I think should be a good choice.  Plus I can buy it locally and get warranty support  just down the street! 

Cheers, Brian

[Sean]

I would encourage you to reconsider this choice.

The 3000 model, while it does have a 3000 watt capacity and twice that in surge rating, can NOT be wired to produce the entire 3kW on a single circuit, which is usually what you need for a coach application.

Instead, the unit's output is divided into two circuits rated 20 amps each.  They may NOT be combined, according to manufacturers instructions.  Moreover, while one of these is a hard-wired output as required by code for coach use, the other is a duplex receptacle, and therefore may only be used to power appliances directly at the inverter's location -- no way to carry that power to another part of the coach.

On top of that, the LBCO is not programmable and is an incredibly low 20 volts.  If you let the batteries go down that far while in use, they will be ruined.  Even the low battery alarm, at 21 volts, is too low.  I recommend an LBCO of no less than 22 volts and an alarm at no less than 23.  FWIW.

So, IMO, this model is a poor choice for a conversion.

-Sean
http://OurOdyssey.BlogSpot.com

[bevans6]

Sean, thanks for point that out.  I wish I could find a unit in my price range that was a simple inverter, decent quality, single output in the 2500 - 3000w range (this one does have 2200 watts), UL approved, and all of that.  It seems such a simple ask, yet so hard to find.  As soon as you move just a bit higher in the quality range, they all have chargers and built in transfer switches and remote programming and I just want a simple inverter.  All I really want to do is run the AC unit on the road from the engine alternator.

The low battery cut out at 10 volts per battery is low, but in my design I will have the DC feed switched through a relay so that the unit doesn't receive DC power unless the alternator is charging, the same as the original bus AC fan motors.  I don't plan to actually run the inverter from the bus batteries alone.  I do plan a future upgrade to run the inverter from a battery bank, but honestly that may never happen.  I already have a 24 volt battery charger, three stage, that can charge up to a couple of hundred AH of batteries.

Can you do me the favor of telling me what inverter for my application you would buy today?

Brian

[belfert]

$1,200 and not direct feed seems a bit steep, but I haven't shopped inverters recently.

You might check Sun Electronics www.sunelec.com.  I bought a factory refurb Prosine 3.0 (3000 watt) for around $800 a few years back.  A disadvantage of the Prosine series is that Xantrex will not fix them unless under warranty and I could not find a Xantrex authorized service place that would touch them.  I fixed the problem I had myself in the end.  I never tried a non-authorized service place.

[ccbmster]

Personally, I have never found that I needed a pure sine wave inverter.

If I were you I would get the Aims 5000/10,000 watt inverter.  I have used one for three years and run air conditioner, LCD tv's, refrigerators, battery chargers, laptops, coffee makers, and my cpap (medical breathing machine) with no problem at all.

I bought mine from the Inverter Store for between $400 and $500 (the Inverter Store usually has the best prices as they are actually a division of Aims itself).

[Slow Rider]

I am surprised that you run your cpap machine on a mws inverter.  The directions on mine specifically say it must be full sine wave.  It would make a huge difference if I could use the aims I already have.

Frank

[cody]

I got my Magnum 2800 watt pure sine wave inverter/charger from trina at RV Surplus for 800.

[JohnEd]

Dang it Cody!  Does she have one for me?  Phone number?

SEAN,  Zantrex unit has a low voltage alarm set for 10.5 volts also as the Aims.  I ain't arguing...why is that a deficient design for Aimes alone?

Thanks,

John

[Sean]

Can you do me the favor of telling me what inverter for my application you would buy today?

This is a hard one to answer, Brian, because I'm not sure what your budgetary constraints are.

For inverter-chargers (which I know you said you were trying to avoid), I favor Magnum:
http://www.magnumenergy.com/productsfront.htm

Their largest non-charger inverter, though, is too small for your needs.

For straight inverters, I think the best in the market are Victron.  Their Phoenix line is a non-charging inverter in true sine wave:
http://www.victronenergy.com/inverters/inverter-12v-24v-48v-800va-3kva/

However, a good alternative (within the service limitations already discussed) is the Xantrex ProSine series, again a non-charging, sine-wave inverter (with remote panel option):
http://www.xantrex.com/web/id/42/p/1/pt/10/product.asp

Unlike many inverter-only options, this one has an incoming AC connection in addition to the output, and a built-in transfer switch.  It is also listed to UL-458.  As had been noted, they can be found used or refurbished.

If you are really on a tight budget, some of the Chinese-made units will work. But I would look for one with a single 3kW output, not split outputs rated at 2,200 watts each.

Personally, I have never found that I needed a pure sine wave inverter.

...  I have used one for three years and run air conditioner, LCD tv's, refrigerators, battery chargers, laptops, coffee makers, and my cpap (medical breathing machine) with no problem at all.

I am sorry to be the one to tell you, but in addition to using about 10-20% more battery power to run these devices, you are also slowly destroying your air conditioner, fridge, and possibly CPAP machine with your MSW inverter.  Of the other things you mentioned, laptops and coffee makers are fine, and the battery charger is a "maybe."

Induction motors such as those found in A/C units, fridges, and other compressor-driven devices, should never be run on MSW power.  In addition to damaging the motors over time, it also presents the risk of fire.

SEAN,  Zantrex unit has a low voltage alarm set for 10.5 volts also as the Aims.  I ain't arguing...why is that a deficient design for Aimes alone?

Many Xantrex units have user-adjustable LBCO and alarm settings.  (Never blindly use default settings; they are almost never optimal.)  However, the ones that don't are also not usually on my "recommended" list -- I am not particularly a fan of Xantrex and almost never recommend their products, with the sole exception of the now discontinued SW series (and that only because of the load-support capability unavailable anywhere else).  The SW series, BTW, has adjustable LBCO and alarm/generator settings.

Trust me on this, if your house batteries get down to 10 volts (on a 12-volt system, 20 on a 24-volt system) you will have done irreparable damage to them.  I consider 11 volts to be a rock-bottom LBCO setting.  Remember, flooded batteries should generally not be discharged below 50% SOC, and VRLA batteries generally not below 20% SOC.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[ccbmster]

Well, I knew someone would tell me I shouldnt run some of that stuff on modified sine waves, but the fact is I have been doing so with the Aims modified sine wave inverter for three years and ran the same things on a Wagan modified sine wave inverter for about two years before that and have not had a problem with any of them at all.

My wife used a cpap for about a year and ran hers on it as well with no problem.

As far as using more energy, I have no idea if that is the case or not.  However my battery bank holds 600 amp hours and can be charged via my solar collectors, shore power, generator, or also from my bus alternator when I am running down the road.  So, lack of battery power has very seldom been a problem for me.

I am not saying anyone is wrong in terms of the advisablity of using modified sine wave inverters for some applications, but until I have a problem I think I will stick with what is working for me.

[cody]

I have been running converters and inverters since 1978, no problems noted of any kind, this magnum is my first that is pure sine wave, I agree that the best power and cleanest wave is pure sine wave but many of the better MSW inverters have a fairly tight step pattern and that is what your looking for, a pure sine wave inverter is mainly an inverter with a tight step pattern, I don't think the inverter has been invented yet that mortals can afford with a flowing wave pattern, they are all in a pattern of steps, some MSW inverters have a very loose step pattern that could have an adverse affect on your electronics but some of the better MSW inverters have a wave pattern that is not far from what the pure sine wave units are offering, some of the better MSW units would probably give good service for a less financial hit than some of the pure sine wave units but a check of some of the surplus centers like RV surplus in Elkhart or Bontragers in White Pigeon Michigan might provide a pure sine wave unit for what a modified would cost depending on their inventory.  I agree with Sean, (yep I said that lol) that pure sign wave is a better fit for some touchy electronics but sometimes the wallet says otherwise, thats my case, I'm damm poor and I have to really search and scrounge to find what I want and sometimes I have to settle for what isn't optimum.

[James77MCI8]

Buy the beat and you only cry once!

[belfert]

Buy the beat and you only cry once!

Or, you buy the buy the best and it still breaks down just out of warranty.  I've had plenty of times where I bought cheap and ended up buying the expensive item later anyhow because the cheap one broke.