How to choose the right size of inverter?

Gdeleon

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Sep 26, 2011
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<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:punctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> I have noticed that a lot of people here have a lot of knowledge of inverter systems (certainly more than I have) and I hope that maybe I can get some help with a decision that I need to make.


I am getting ready to purchase an inverter and I am trying to decide which size would be the best choice. I have added up all of our current usage (120v) and come up to around 2200 watts of use. So given startup demands from motors, I would guess that a 3.6 would be very good, for now. But knowing how things go, we will probably be adding more electrical stuff in the future and it seems that I should buy even a higher output inverter so as to have extra available for the future. So, my question is there any downside (other than the purchase price) to having a inverter larger than your usage needs? I realize that if you go from the 24v to 48v system you will need more batteries, but I wonder if a larger inverter would be somehow less efficient than a smaller, closer to demand/load size unit? I am looking at 3.6, 4.0 and 5.5 sizes at this point.

Thanks in advance for any suggestions.
 

beeza

Silver
Nov 2, 2006
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Your knowledge seems quite well founded and you have asked a good question.

Inverter efficiency can vary from 50% to 90% depending on it's load. The higher you load an inverter, the more efficient it becomes, up to the point where you overload it. For your current needs I would say that a 3kva would be sufficient and return a reasonable level of efficiency.

The output wave also makes a difference in efficiency too. A modified square wave is less efficient. You can hear that loss of efficiency when it's running something like a ceiling fan, it will make a noticeable hum.

Now some high end inverters are quite efficient. I have a Trace 5.5kva sinewave inverter. The output wave is almost identical to a generator output, so no humming and loss of efficiency there. It also has a "seek" mode where it adjusts it's output power according to the load required, so it sort of "tunes" itself for optimum efficiency and battery consumption.

But it all comes down to price. My inverter cost over RD90,000 excluding batteries three years ago, whereas you could probably get a complete installation of a basic inverter and batteries that would meet your requirements for less than a third of that price.
 

Castellamonte

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Mar 3, 2005
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Excellent information here in both posts. I might add a third element of consideration in the acquisition of the inverter; the ability to have it repaired.

I had 5 of the 5.5kva Trace inverters at my house (it's kinda big) and while they worked well it was a nightmare to get them fixed once they failed (and everything fails). I had to get them to Santiago or Santo Domingo as I couldn't find anyone here in Cabrera or Nagua who could reliably fix them. So I ended up replacing the entire inverter bank with 3.6Kva Trace.

The funny part here is that the 3.6Kva Trace (2 of them) are less expensive than one of the 5.5Kva Trace plus I can run them to my favorite Cuban in Nagua who can fix them in a heartbeat when they fail. So now I have a wall full of 3.6Kva, had to re-balance the electrical system in the house mind you, but am happy I made that decision.

So consider maintenance as a key element. Know where you can get them fixed, reliably and nearby, before you buy!

P.S. Just because a place sells them does not mean they can fix them.
 

Gdeleon

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Sep 26, 2011
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Thank you both very much for this information. I have been leaning toward the true sine wave inverter and looked at a couple at the Megatron (sp?) store in Moca.

Beeza, based upon your information, I did some checking on the Trace/Xantrex sine wave inverters and as you stated, they are very efficient. If you don't mind, could you tell me where you purchased your Trace inverter? I live in the Santiago area so anywhere on the North Coast is convenient.

Castellmonte your concerns are well-founded as the ability to find someone to work on the system is essential. Is there any thing in particular that you think caused your 5.5 Kva to fail? Am I correct to assume that your 3.6 units are not the pure sine wave models and if so, do you find them more resilient to problems?

Thanks again for your posts as it is very helpful for me to get some real-world feedback from folks like yourselves.
Also, be careful today with all of the amateur drunks on the highway (or in the ditch?).
 

lisagauss

Bronze
Feb 16, 2011
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Thank you both very much for this information. I have been leaning toward the true sine wave inverter and looked at a couple at the Megatron (sp?) store in Moca.

Beeza, based upon your information, I did some checking on the Trace/Xantrex sine wave inverters and as you stated, they are very efficient. If you don't mind, could you tell me where you purchased your Trace inverter? I live in the Santiago area so anywhere on the North Coast is convenient.

Castellmonte your concerns are well-founded as the ability to find someone to work on the system is essential. Is there any thing in particular that you think caused your 5.5 Kva to fail? Am I correct to assume that your 3.6 units are not the pure sine wave models and if so, do you find them more resilient to problems?

Thanks again for your posts as it is very helpful for me to get some real-world feedback from folks like yourselves.
Also, be careful today with all of the amateur drunks on the highway (or in the ditch?).

Could you post some prices from your research. THanks!
 

beeza

Silver
Nov 2, 2006
3,479
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Beeza, based upon your information, I did some checking on the Trace/Xantrex sine wave inverters and as you stated, they are very efficient. If you don't mind, could you tell me where you purchased your Trace inverter? I live in the Santiago area so anywhere on the North Coast is convenient.

I bought mine from the official Trace/Xantrex dealer in POP. It came with a full two year guarantee. In order to get that guarantee, they insist on installing and setting it up themselves. Believe it or not, there's quite a lot of programming involved as it's quite sophisticated.

Touch wood, never had any problems at all with it. It also maintains the batteries really well too. I have hardly had to add any water to them and their capacity is still very good after three years. The important thing about battery maintenance is by monitoring temperature. My inverter comes with a battery temperature sensor and charges / conditions them accordingly. I'm using the green top Interstate batteries which I bought from autoadornos Los Santiagueros in POP
 

Gdeleon

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Sep 26, 2011
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Could you post some prices from your research. THanks!

I am still just in the "tire-kicking" phase of my research and trying to decide what I really need/want so I am not really focusing too much on the prices, just in a general sense for the sake of comparison . Once I narrow everything down, then I will start negotiating the prices. However, if you looking for any specifics, let me know and I will do my best to help. Are you looking for an inverter as well?
 

Gdeleon

New member
Sep 26, 2011
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I bought mine from the official Trace/Xantrex dealer in POP. It came with a full two year guarantee. In order to get that guarantee, they insist on installing and setting it up themselves. Believe it or not, there's quite a lot of programming involved as it's quite sophisticated.

Touch wood, never had any problems at all with it. It also maintains the batteries really well too. I have hardly had to add any water to them and their capacity is still very good after three years. The important thing about battery maintenance is by monitoring temperature. My inverter comes with a battery temperature sensor and charges / conditions them accordingly. I'm using the green top Interstate batteries which I bought from autoadornos Los Santiagueros in POP

Beeza, I went by the Trace dealer today in Santiago and I must say that I am impressed with their inverters. I am leaning toward the Xantrex based on your experience and from what I gleaned from the dealer today. Is there any reason you did not use the Trace batteries as well?
 

beeza

Silver
Nov 2, 2006
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Beeza, I went by the Trace dealer today in Santiago and I must say that I am impressed with their inverters. I am leaning toward the Xantrex based on your experience and from what I gleaned from the dealer today. Is there any reason you did not use the Trace batteries as well?

I already had batteries and just needed the inverter. When those ones packed up I replaced them with Interstate due to price.

As far as I am aware Trace don't actually manufacture batteries, it is a crafty marketing ploy. The consensus is that if you want the best batteries, go with the Trojan red-wine ones. Expensive though.

I'm happy with the Interstate ones that I bought as they were backed up with a 1 year guarantee, followed by a two year partial guarantee.
 

lisagauss

Bronze
Feb 16, 2011
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I am still just in the "tire-kicking" phase of my research and trying to decide what I really need/want so I am not really focusing too much on the prices, just in a general sense for the sake of comparison . Once I narrow everything down, then I will start negotiating the prices. However, if you looking for any specifics, let me know and I will do my best to help. Are you looking for an inverter as well?

Hey, yes I will be in need of an inverter in the very near future. I was thinking of going with a 5KVA one, maybe trace. Let me know if you see anything worthwhile.
 

windeguy

Platinum
Jul 10, 2004
42,087
5,914
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Trace does not make batteries and never did. Who knows where those batteries marked with Trace logos are from.
Get Trojan Red batteries if you can.

Trace is now called Xantrex. Any new inverters will have the Xantrex logo. Trace made a very good inverter, but do yourself a favor and compare them with the ones sold by Inverluz (in Moca)/Megatone (in Puerto Plata). The Inverluz/Megatone inverters are very similar to Xantrex in performance and at a significantly lower cost to purchase and repair.

Xantrex | Power Inverter, Inverter Charger, Battery Charger Manufacturer

INVERSORES, BATERIAS, REGULADORES, TRACE, TROJAN T105
 

donP

Newbie
Dec 14, 2008
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Trace

Trace does not make batteries and never did.
True.
However, my first set of batteries (16) were TRACE T-115 and they were (back in 1998) not bad at all. I nursed them to almost 5 years, although they were very weak in the end...

Now my fourth set are again TROJAN T-105, the red ones; as said most likely the best.

We use 2 Trace inverters DR3624 (stacked for 230 V also) and have another two on standby (because inverters always give in on weekends... :tired:

We have no problems with the modified sine wave models.

donP