Cheapo Inverters vs. Expensive Ones

[eric@psmnv]

If warranty is the same and the company will be around for the length of the warranty, possibly not.

Thanks. Now I'm getting closer to an answer. It doesn't mean I'm necessarily going to buy something cheapo. It just means that I want to understand the differences before making a decision.

[lkruper]

I think you're still missing the basic question. I'm just comparing the $2200 Magnum inverter sold by wholesalesolar.com in their off-grid kits to cheaper inverters with the same specs. Are you saying that the Magnum inverter sold by wholesalesolar.com which has the same specs is also unsafe? Should I contact them and ask how they can sell such an unsafe product?

They don't have the same specs:

Safe and reliable: The MS2000, MS2012, MS2812, and MS4024 are ETL
Listed to the stringent requirements of UL/cUL 458 for mobile use and the
MS2012, MS2812, and MS4024 are ETL Listed UL 1741 and CSA C22.2 #107.1-
01 for renewable energy installations. All models also meet KKK-A-1822E
standards for emergency vehicle use.

[eric@psmnv]

Do you understand the burden of proof concept?

Now, don't be mean. I thought you said earlier that the UL listing met your requirements for burden of proof. It now appears that you are adding "verifiable reviews" to the requirement, which is reasonable. What other elements do you consider necessary to meet the burden of proof to your personal satisfaction? Aside from a UL listing and verifiable reviews, what else does a web site need to display to meet your standard of proof?

[eric@psmnv]

From the link itself I can see that it is a 5000w inverter which will not be safe (ie > 100 amps) even at 48 volts.

I think you're still missing the basic question. I'm just comparing the $2200 Magnum inverter sold by wholesalesolar.com in their off-grid kits to cheaper inverters with the same specs. Are you saying that the Magnum inverter sold by wholesalesolar.com which has the same specs is also unsafe? Should I contact them and ask how they can sell such an unsafe product?

[lkruper]

My previous comment was to someone else, but thanks for your input.

Unfortunately, I still have not seen an answer to the basic question. Assuming an inexpensive inverter in the $600 range can be located that features the coveted UL mark, is there any reason to think that it would not do the job as well as the seemingly overpriced Magnum unit?

Irrelevant (to me). They vendor has the burden of proof, and the web sites don't provide any. I never buy anything without verifiable reviews and even then I don't always trust the reviews.

Do you understand the burden of proof concept? It means that the one making the claim bears the burden of proof, a proof that is non existent in these products.

[inetdog]

My previous comment was to someone else, but thanks for your input.

Unfortunately, I still have not seen an answer to the basic question. Assuming an inexpensive inverter in the $600 range can be located that features the coveted UL mark, is there any reason to think that it would not do the job as well as the seemingly overpriced Magnum unit?

If warranty is the same and the company will be around for the length of the warranty, possibly not.

[eric@psmnv]

I am done following links.

My previous comment was to someone else, but thanks for your input.

Unfortunately, I still have not seen an answer to the basic question. Assuming an inexpensive inverter in the $600 range can be located that features the coveted UL mark, is there any reason to think that it would not do the job as well as the seemingly overpriced Magnum unit?

[lkruper]

I hear you, and I am certainly in that phase right now, but I do not give up easily. Here's a page that lists about a zillion similar products.

http://www.alibaba.com/showroom/5000w-power-inverter-48v-pure-sine-wave_3.html

I have a hard time believing that all these products are out there causing fires in homes all over the place.

I am done following links. None of them meet the burden of proof. From the link itself I can see that it is a 5000w inverter which will not be safe (ie > 100 amps) even at 48 volts. Without a UL listing I would not touch it.

[eric@psmnv]

Same problem. It is available in a 12V version that they claim goes to 10,000 watts surge. 10,000 watts/12 volts at 90% efficiency is 925 amps. Those terminals (and likely the guts of the inverter) cannot handle almost 1000 amps without a (probably spectacular) failure.

That means they are lying. What else are they lying about?


Yep. Think they are telling the truth? For example, do you think for IEC 60950-1 testing, they told the test lab to test at 5000/10,000 watts? Or did they perhaps told the test lab "this is rated for 1000 watts" when they submitted it, to ensure it passes?

I think everyone goes through a phase like this when they get involved with alternative energy. "Hey, I found instructions that let me build a solar panel for pennies!" "I could take this old alternator and build a super-efficient wind turbine that will work in low winds." "Look how cheap this inverter/charge controller is!" Then you make those mistakes a few times and learn. It may be that you have to make the same mistakes. Since this is a fairly inexpensive inverter ($395) it will be a cheap lesson.

I hear you, and I am certainly in that phase right now, but I do not give up easily. Here's a page that lists about a zillion similar products.

http://www.alibaba.com/showroom/5000w-power-inverter-48v-pure-sine-wave_3.html

I have a hard time believing that all these products are out there causing fires in homes all over the place.

[jflorey2]

Here's a better example. http://www.alibaba.com/product-detai...5.1.uhv2wj&s=p Why would an inverter like this not work just as well as a $2K inverter from Magnum?

Same problem. It is available in a 12V version that they claim goes to 10,000 watts surge. 10,000 watts/12 volts at 90% efficiency is 925 amps. Those terminals (and likely the guts of the inverter) cannot handle almost 1000 amps without a (probably spectacular) failure.

That means they are lying. What else are they lying about?

Did you scroll down to the certifications section?

Yep. Think they are telling the truth? For example, do you think for IEC 60950-1 testing, they told the test lab to test at 5000/10,000 watts? Or did they perhaps told the test lab "this is rated for 1000 watts" when they submitted it, to ensure it passes?

I think everyone goes through a phase like this when they get involved with alternative energy. "Hey, I found instructions that let me build a solar panel for pennies!" "I could take this old alternator and build a super-efficient wind turbine that will work in low winds." "Look how cheap this inverter/charge controller is!" Then you make those mistakes a few times and learn. It may be that you have to make the same mistakes. Since this is a fairly inexpensive inverter ($395) it will be a cheap lesson.

[lkruper]

Did you scroll down to the certifications section? There's a lot of information on the page. Overall, it looks pretty legitimate. Is UL listing the only way that you check a product's worthiness or safety? That said, suppose for the sake of my original question that I eventually find one that has the UL mark in the same price range. The real question is, is there any reason to think that a $700 inverter would not do the same job as a $2200 Magnum inverter?

When I pulled up certs I did not see anything. And yes, if the unit is to be used in the USA, then UL listing is important, if not critical when installed in a residence where my family lives. Would it do the same job? Like I said, THEY bear the burden of proof, a burden I have not seen met.

So, whether or not I give you a reason, it is irrelevant. I do not have the burden of proof, the manufacturer does. And I see none.

[eric@psmnv]

It has all the same problems as the other example. No UL listing, no proof of worthiness or safety. The web site and product must meet the burden of proof, not the other way around. You should be asking the question, how does this site prove the product is acceptable and not assume it is unless it can be proven otherwise. What do you expect from a sales web site, that it give accurate and dependable reviews and information?

Did you scroll down to the certifications section? There's a lot of information on the page. Overall, it looks pretty legitimate. Is UL listing the only way that you check a product's worthiness or safety? That said, suppose for the sake of my original question that I eventually find one that has the UL mark in the same price range. The real question is, is there any reason to think that a $700 inverter would not do the same job as a $2200 Magnum inverter?

[lkruper]

Here's a better example.

http://www.alibaba.com/product-detail/original-manufacture-5000w-12v-24v-48v_447508088.html?spm=a2700.7724857.35.1.uhv2wj&s=p

Why would an inverter like this not work just as well as a $2K inverter from Magnum?

It has all the same problems as the other example. No UL listing, no proof of worthiness or safety. The web site and product must meet the burden of proof, not the other way around. You should be asking the question, how does this site prove the product is acceptable and not assume it is unless it can be proven otherwise. What do you expect from a sales web site, that it give accurate and dependable reviews and information?

[eric@psmnv]

Here's a better example.

http://www.alibaba.com/product-detail/original-manufacture-5000w-12v-24v-48v_447508088.html?spm=a2700.7724857.35.1.uhv2wj&s=p

Why would an inverter like this not work just as well as a $2K inverter from Magnum?

[eric@psmnv]

5000w / 48v = 104 amps is a fire waiting to happen.

In that case, it's also a fire waiting to happen for these guys...

http://www.wholesalesolar.com

...because a lot of their off-grid kits are built around the Magnum inverter previously mentioned with the same specs.

The web site is amateurish and contains grammatical errors.

I knew I was taking a risk of confusing the question by using that particular product as an example. You're right, that one looks shady. I wish I had used a different example. However, as I mentioned originally, a lot of vendors sell inverters with the same specs in the $500-700 price range.

I probably didn't ask my question quite right. Issues of warranties aside, all I want to know is, electrically speaking, is there any reason why a cheapo inverter in the $600 range would not do the same job as the expensive $2200 inverters sold by wholesalesolar.com?