Modified Sine Inverters??

[bevans6]

What is the standby draw on these inverters (which look really very good, btw)?  I live in fear of forgetting to turn the inverter off and draining the batteries even if the inverter isn't supplying a load.

Brian

[Busted Knuckle]

What is the standby draw on these inverters (which look really very good, btw)?  I live in fear of forgetting to turn the inverter off and draining the batteries even if the inverter isn't supplying a load.

Brian

Brian I can't answer yer question, but a good fear I must add as I have seen it happen back when I was driving trucks on a regular basis! (and don't ask me how I know this!  , but I was one of the few truckers out there that had quick connect jumper cables made to jump my refer units from the tractors & vise versa! , )

Now on the other hand I think these days most of the inverters have a low voltage shut off built in. And even the high end units offer a setting that you determine what voltage they shut off at! (I think!)
  BK 

[JohnEd]

Brian,

I recall seeing inverters that had a offline draw of .1 amps.  They use that draw to power a circuit that checks the inverter load for a "need" to invert.  There seems to be three modes that draw.....in use, relaxed after use and in some sort of deep slumber from which it will awaken automatically.

There are some uncommon features that are worth looking into as along as you are spending large.  One is the ability to look at the current draw "from the pole" or generator and see an overload coming.  The inverter syncs up with the ac and adds ac power from the bats to keep the pole breaker from tripping.  That might come into play when you want to run two AC units from a 30 amp pole.  While the pole can run them it needs help to start one with the other running or two simultaneously.  Neat huh?

The other is that the inverter will cheat the bat charger as the input ac current demand for appliances fluctuates.  It is set to "always" give the charger as mush as it possibly can without popping the pole breaker.

Then there is being able to sync an inverter to another source to allow making 220.....two inverters.  If I needed 4  KW i think I would be tempted to get two 2 K units and run two 120 phases and be able to have 220 for whatever.

2 cents,

John

[belfert]

There are a very limited number of inverters that can be ganged for 220 volts or do load sharing.  The Trace 4024 inverter did load sharing, but it is discontinued I believe. 

It looks like the Xantrex RS3000 will do the load sharing, but it doesn't appear to be stackable  Magnum Energy has an inverter that does 240 volt with one inverter or they have one model that can be stacked.  They are both 24 volt 4000 watt inverters.

[luvrbus]

I have stacked inverters for 220V all the better inverters can be stacked that I know of

good luck

[belfert]

I have stacked inverters for 220V all the better inverters can be stacked that I know of

It can certainly be done.  The problem is most of the inverters targeted at the RV market don't do stacking.  I've listed above the only two I could find on a quick search.  I am pretty sure the Xantrex/Trace SW4024 does it, but it appears to be discontinued.

Outback makes some nice (not cheap!) inverters, but their mobile inverters make no mention of stacking.

[pvcces]

There are three esses (sss) involved with these inverters and they are easily confused. Sharing, stacking and supplementing. Some dealers seem perfectly willing to sell an inverter whether the customer knows what he is buying or not.

To keep it simple, power sharing is only the ability to cut back charger draw when there are heavy loads. Many full inverter chargers have this feature. This feature is intended to prevent tripping of shore power breakers unnecessarily.

Power supplementing, also called generator supplementing, will use battery power when the generator cannot carry the full load and resume charging batteries when the load drops. This feature is intended to maintain voltage on the power line. I only know of one brand of inverter that does this. That is Trace. Not all models do this. The SW series and the PS series have this feature.

Power stacking is using more than one inverter to either increase voltage or current. The Trace line has this feature as an option. So does the Outback, at least in some models. This feature synchronizes and matches phases. I have seen ads by Outback saying that you could connect them for three phase power, as well. I'm sure there are more, but I don't know which ones.

I'm sure that some of this information is dated. It is only mentioned here to minimize confusion.

For what it's worth.

Tom Caffrey

[JohnEd]

Tom,

And you did that nicely.

Thanks,

John

[Gary LaBombard]

I have purchased one of these with the intention to buy more, I have not used it yet so I can't give any feedback but what is your opinion of these kind of inverters.  I hope I will not be sorry to have asked this question but here is the ebay location of one of these inverters.  They also sell those that have 240A output that can be ganged I believe.

http://cgi.ebay.com/STACKABLE-POWER-INVERTER-2500-5000-W-12V-DC-TO-120V-AC_W0QQitemZ390127064133QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5ad5629445

Merry Christmas by the way.

Gary

[cody]

Gary, I've never heard of 'semi-pure sine wave'.

[Nick Badame Refrig/ACC]

Here is the only thing I found on Simi Sine Wave..?

http://www.fieldlines.com/story/2009/5/8/19954/26784

[luvrbus]

It is not the standby draw or the efficiency that keeps me from changing to pure sine it is the power lost for the operation of the pure sine units even the RS Xantrex,Outback and Magnum uses over 10% for their own use when they get over that hump I'll buy pure sine.  


good luck

[JohnEd]

Well that thing seems to cost what I think they should be worth including the shipping from China.   Considering the drop in cost of the components it might even be a little high.  The performance for the dollar is great and will be for a long time.  I like the idea of stackability and I want to see the "other" inverters automatically come on line as needed....OOOHHHH!  That low battery voltage alarm, adjustable, is the signal that your genney needs for auto start.

The reference link that Nick provided sited the failure of a unit after 2 years of use.  That inverter had a cooling fan go out after a year.  He DIDN"T replace the cooling fan but instead put a house fan on the thing and cracked open the case.  It worked that way for another YEAR then crapped out, due to overheating, when it got full of dust and a wasps nest got built in it and he forgot to use the makeshift fan.  The piece of Chinese "junk", I say.  There would be many with sad tales to tell if these things were even a little unreliable.  The cost puts them over the goal line.

So just where the heck is the BATTERY CHARGER?  Where is the 150 amp charger?  Those cost like the dickens if they are stand alone and multi stage/smart.  That pushes me away.

I have such hugely mixed and conflicted about these imports.  I should be able to buy American and I would have to do without a lot of things due to cost and others due to a lack of a domestic manufacturer and that is just not right.  The American worker is once again the most efficient in the world.  Our wages are, in fact, LOWER than Japan or Germany or even France and the cost of our goods isn't all that competitive.  Our work force suffers and our wages continue to drop.  We did a lot better when 50% of our work force was unionized.  Boy, could this ever turn into a rant.


My Xantrex Freedom is tits up.   I called the only two shops that can repair them and was told it would probably cost 12 to 13 hundred to repair and possibly MORE.  They had a "deal" for me:  They would ship me a knew inverter  to use while mine was in the shop and all I had to do was give them the cost of the new unit as a deposit.  If the "repair" worked out to be more than the cost of the new unit, then they would just consider it a sale.  $18,000 bucks plus shipping.  Makes you wonder just who these people are accustomed to dealing with.  Go XANTREX!!!....you go GIRL.  Buy loc..... never mind.

Never a dull moment,

John

And a happy holiday season to all and may His/Her blessings be upon you.

[cody]

My Magnum 2800 is pure sine wave and I paid about 850 for it, I still havn't figured out what semi-pure sine wave is, one guy that deals with electrnics says it's a quasi way to say modified sine wave and that in electronics semi pure sine wave doesn't exist, only in marketing.

[JohnEd]

AND JUST WHERE DID YOU GET THAT Magnum???  Please?

Thanks,

John