Cheap Chinese inverter reviews?

CALLDCALLD Solar Expert Posts: 230 ✭✭
For me the biggest problem with cheap Chinese products is actually the lack of reliable information and reviews on them rather than inferior quality. When it comes to "pure sine wave" inverters we all know they are traditionally very expensive. But lately the market seems to be flooded with Chinese TSW inverters with price tags that are truly pricing traditional MSW inverters out of the market.

I for one recently purchased a Ningbo Kosun 24v 2500w TSW inverter for less than $400!

But what about the potential problems that one may encounter with these "quote me happy" inverters?
They are so fresh on the market there is no independent feedback available on most of them.

IMO there are some advantages of going the cheap Chinese route, based on my experience with the Kosun TSW inverter:
* They could incorporate the latest high-performance technology (even though its cheap)
* They can be highly efficient due to the use of more solid state digital components and less analogue/mechanical components. Mine for example has no large transformer.
* Low upfront cost makes purchasing a higher capacity unit is possible giving more freedom to expand and/or lower percentage load on the unit = lower operating temperature.

Issues I have picked up with mine are as follows:
* Unstable AC ouput voltage when loads are under 400watts (16% load). The inverter's voltage regulating feedback loop does not switch smoothly under 16% load and creates sharp irregular amplitude pulses on the AC output. The amplitude pulses do however fall within the 10% AC regulation specification in the manual, but due to their frequency and irregularity it can be very annoying when using CFL or LED lighting as it causes them to flicker. The unstable feedback loop also causes high-current pulses on the DC side which register on the kilo-amper scale even when the average current is only in the single digits. You can actauly "feel" these high current pulses in the battery cables due to the magnetic inductance!
* At loads exceeding 16% the voltage regulating feedback loop stabilises and so does the AC output, however a small amount of high frequency noise is detectable in the AC power but is not an issue for concern.

Other than these issues I have no other complaints and would recommend this inverter for anyone who needs a TSW inverter on a very tight budget!

The only thing that remains to be seen is the long term reliability of the unit. It comes with an 18 month factory workmanship and material defects warranty. Mine has been going pretty much 24/7 for the last 4 months. I would however tend to feel that the unstable feedback loop at <16% loads may be putting additional strain on the components although having no experience in this particular field I cannot say that for sure. As such I try to run >16% loads wherever I can.

If anyone else has experience they would like to share on budget Chinese inverters please post here!

Regards,
D
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Comments

  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    I have been using one of them now in test mode for 2 months. 2000w and 12v. cost $150US.. An almost unbelievable price..
    So far it has performed ok but as yet not subjected it to loads above about 500w.... It runs very cool. but certainly draws more current than the one it replaced . it draws 1.8a compared to 800ma for the previous one that cost $750US.
  • CALLDCALLD Solar Expert Posts: 230 ✭✭
    Re: Cheap Chinese inverter reviews?
    john p wrote: »
    I have been using one of them now in test mode for 2 months. 2000w and 12v. cost $150US.. An almost unbelievable price..
    So far it has performed ok but as yet not subjected it to loads above about 500w.... It runs very cool. but certainly draws more current than the one it replaced . it draws 1.8a compared to 800ma for the previous one that cost $750US.

    I've always been amazed at high-powered inverters that run on 12v - in fact kosun has a 6000w inverter that they reakon can pull that amount of power from 12v! I can only imagine what the components inside look like......

    Anyway, interesting thing on current draw - mine does a very strange thing when it crosses over the 400w threshold I mentioned earlier: the current draw actually drops by a few amps as the load increases over 400 watts! Load of 380 watts draws 17.1A at 25,4v, load of 405watts draws 16.2A at 25.4v. All the way up to full load the inverter only appears to draw a dozen or 2 watts of power over the theoretical 100% efficiency value. It still baffles me how they could achieve this but couldn't design it to do that across all load levels. Wish I was an electronics engineer so I could understand these things fully.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?
    CALLD wrote: »
    I've always been amazed at high-powered inverters that run on 12v - in fact kosun has a 6000w inverter that they reakon can pull that amount of power from 12v! I can only imagine what the components inside look like......

    These high output, low Voltage input inverters should be avoided like the plague. Just do the basic math and you'll see why. Any company promoting such a design clearly doesn't have sound engineering behind it, and you should be suspicious of any products from such a company.
  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    Cariboocoot there can be good reasons to buy a 12v 2000 w inverter.. I have such a reason.. I normally use the inverter to power my desktop computer draw about 300w.But because of many blackouts its easier to use a permanent inverter as supply and cheaper than buying a UPS.. Now the reason to want 1000w or above.. During blackouts on daytime we run the fridge from 10am to 3 pm on the inverter.. You need an inverter to have a continuous output above 1000w to relaiably start a fridge.. after that the draw is less than 150w...Because the high current draw is so very short about 3 seconds you can get away with #8 cable.. it wont have a temp rise above a few degrees.
    Ibought the 2000w inverter to replace a good 1000w one.. Icould have bought a 1000w 12v one again but the 2000w price was only $12US more than the 1000 w version..

    As for reliability will thats unknown as only used it now 2 months.But seeing the 1000w one cost over $750 and lasted 6 yrs and this one $150 so even it lasts 2 yrs im way ahead.

    Now dont get me wrong im certainly not advocating everyone that needs to have an inverter that can supply over a 1000 w continuously buy a 12v one,, that would be crazy .My usual rule of toe is 12v per 1000 w inverter
  • inetdoginetdog Solar Expert Posts: 3,121 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?
    john p wrote: »
    Now dont get me wrong im certainly not advocating everyone that needs to have an inverter that can supply over a 1000 w continuously buy a 12v one,, that would be crazy .My usual rule of toe is 12v per 1000 w inverter
    Others who have a lot of experience in off grid and recognize that a larger inverter usually means higher tare (no load) losses will put the cutoff for 12 systems at about 300W and will use one large and one small inverter and only switch the big one on for large loads.
    If your large inverter has a low power standby/search mode AND the appliance being driven does not need constant power for something like a defrost cycle timer, you can connect the large loads directly to the large inverter and your smaller loads to the smaller inverter and get the best of both worlds.
    SMA SB 3000, old BP panels.
  • CALLDCALLD Solar Expert Posts: 230 ✭✭
    Re: Cheap Chinese inverter reviews?

    The problem I have with low voltage high powered inverters is resistive losses. Even if we assume technology is getting to a point where a 12v 6000w inverter can perform well with >90% efficiency the problem is going to be with the wiring and the batteries. Even SLI batteries cannot provide the required current without the voltage dropping well below the Low Voltage Disconnect threshold of the inverter. Very large VRLA/AGM/Gel batteries may be able to supply the current for a useful length of time but we are talking around 1000Ah capacity and wiring that resembles the Golden Gate Bridge main cables.
    I reakon my 24v 2500watt inverter is pretty much at the sane limit for what you should be pulling from a 24v battery - and I'm using VRLA/AGM batteries...
  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    Inetdog.. In fact that is what I do for our lighting we use a 400w MSW inverterat all times .. And it runs on average about 140w.. the other reason is its very low own current draw only 280mv. at 200 w its over 90% efficient.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?

    There's a HUGE difference between a 2kW 12 Volt inverter and the 6kW 12 Volt inverter CALLD referred to. A 2kW unit on 12 Volts is perfectly normal. A 6kW unit on 12 Volts will be pulling >500 Amps at full power, which is just nuts.

    I have seen 12 Volt units with 10kW rated output using four separate parallel DC inputs. This is insane and very bad design.
  • jimindenverjimindenver Solar Expert Posts: 59 ✭✭
    Re: Cheap Chinese inverter reviews?

    I had a Power Jack 3000/6000w PSW unit that was fine running the Microwave, auto drip coffee makers and such. Then I plugged in a 5000 BTU air conditioner and after starting the compressor once, the voltage was all over the board. Anywhere from 65v to 140v+. I haven't contacted the seller and have heard they are not so good about honoring the warranty, but I'll try anyways.
  • CALLDCALLD Solar Expert Posts: 230 ✭✭
    Re: Cheap Chinese inverter reviews?
    I had a Power Jack 3000/6000w PSW unit that was fine running the Microwave, auto drip coffee makers and such. Then I plugged in a 5000 BTU air conditioner and after starting the compressor once, the voltage was all over the board. Anywhere from 65v to 140v+. I haven't contacted the seller and have heard they are not so good about honoring the warranty, but I'll try anyways.

    There's a scathing review somewhere on the net about a powerjack inverter, read it a few months ago - nothing good about it at all. If it's true it really makes you feel helpless about what you're paying money for when you're looking for a bargain.

    My 2500w Kosun runs my 14000btu AC, power tools, wife's 2000w hair drier, kettle and will even start a 2000watt leaf blower without even flinching! It's when loads are under 400watts that it doesn't really know what to do with itself...

    I suppose bargain deals are a bit of what this thread is about. We all know the safest bet is to go with premium brands that have stood the test of time, but not everyone has the confidence to make that investment when they are still in the novice phase. Another thing to consider is that true bargains can and do exist, you will always find people who have paid a quarter of the price for something that does exactly the same thing and keeps on doing it for many years! That's what we are after here...
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?

    People, if you value your familys safety youll avoid these cheap inverters for off grid hardwire, like the plague just as coot said. Do you really want someting in your house capable of burning your house down... something where in order to meet the price point every possible corner has been cut, the cheapest possible components used. No sir, you do not.

    As someone said here, buy quality, and you only cry once, at the start.

    BTW if those kosun units are the yellow or blue alloy cased ones, with no discernable branding, then i know a guy who brought in a container, and he said that fully 20% failed within the first week. That tells you something about the QC, and about why they dont want their name on the product. With inverters brand is everything. Also beware they have no case earth usually, so possible shock hazzrd there.

    However, I hear that if they survive that first week, they arent bad units, and suitable enough for the odd power tool on the back of a truck, sort of thing.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • jimindenverjimindenver Solar Expert Posts: 59 ✭✭
    Re: Cheap Chinese inverter reviews?
    CALLD wrote: »
    There's a scathing review somewhere on the net about a powerjack inverter, read it a few months ago - nothing good about it at all. If it's true it really makes you feel helpless about what you're paying money for when you're looking for a bargain.

    My 2500w Kosun runs my 14000btu AC, power tools, wife's 2000w hair drier, kettle and will even start a 2000watt leaf blower without even flinching! It's when loads are under 400watts that it doesn't really know what to do with itself...

    I suppose bargain deals are a bit of what this thread is about. We all know the safest bet is to go with premium brands that have stood the test of time, but not everyone has the confidence to make that investment when they are still in the novice phase. Another thing to consider is that true bargains can and do exist, you will always find people who have paid a quarter of the price for something that does exactly the same thing and keeps on doing it for many years! That's what we are after here...

    Sometimes the deals work out, like the $100 MPPT controllers I use. They do what they say they will but are limited on features. Need those and You will spend three times as much. I just had a hard time justifying a $325 Rogue to run a single $50 craigslist panel when I didn't even know if solar would work for our RV.

    The PJ did work out in a sense. I needed to see if I could use more panel to run things while having a smaller bank. The 490w of panel I used this summer allowed use of a 1375w microwave for 8 minutes without sagging the voltage on a 8-D below 12v. For a time 720w was running the AC without pulling the battery out of float and that's at 5000 ft, I get more out of the system at 10,000 ft.

    So not only did going cheap allow me to see if the concepts would work, it also let me avoid some costly mistakes. The Rogue 30a was recommended for my cheap panels but back yard testing showed me their Voc's were always different and would confuse the controller. Even if I did have a match for the 230w, I would have seen clipping at altitude. I picked up two 245w Bosch panels for $170 and know a TR-MPPT-45 will be the better choice. I went PSW with the inverter because I was told the satellite system needed it. The PJ also had a issue with small loads and would blink off when just running the TV/Sat. Just that instant would cause the satellite to have to reset and that took 10 minutes. I ended up running it on a 150w MSW inverter and it did fine. So now instead of spending the crazy bucks for a high end PSW inverter, I'm looking at a Tripp lite industrial MSW unit. I may get a morningstar 300w fanless PSW in the future for electronics. I have until spring to decide but it seems the best way to spend the money. Now I just have to decide on what batteries and where to put them and i will be a happy camper.
  • CALLDCALLD Solar Expert Posts: 230 ✭✭
    Re: Cheap Chinese inverter reviews?

    Jim,

    Yes it's all about the learning curve isn't it? I think there are two types of people in the solar electric camp:

    1) those who decide they want to go solar and spend lots of time researching it, talking to their wives, family and just about everyone else and once they're completely happy with their decision they go and get their system, perhaps even paying the professionals to come and install it for them.
    2) those who never really planned to take it as far as they did but were nonetheless curious. These people could have started out contemplating a generator after sitting in the dark one night when the grid failed, but before going out to get a generator considered the noise and pollution factor. They then go and buy a cheapie UPS and some batteries. After many months pass without a single power outage they see some PV panels on display at their local electric store and the idea pops into their head that well, the UPS and the batteries are already sitting there doing absolutely nothing waiting for an outage that may or may not happen so why not see what adding some PV could do? Curiosity rules and a new hobby is borne!

    I'm in the 2nd camp, it all started from there and along the way I've been slowly replacing the cheap stuff with better stuff as I've learnt. 1st thing I replaced was the MSW UPS with the TSW inverter I have now, 2nd thing I replaced was my old Leisure battery bank with deep cycle AGMs. When the time comes the Kosun inverter will have to make way for a premium inverter that performs perfectly across all loads. When the budget allows I will add more PV and get a premium MPPT controller. This will be timed for when my batteries are up for replacement as by then the entire system will be upgraded. This is how we learn...
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?

    Third group:

    Those with a lot of education and experience who are perfectly willing to share same with others so they won't have to go the trial-and-error money-wasting route buying junk equipment to find out the hard way if solar is a viable option for them.

    ;)
  • CALLDCALLD Solar Expert Posts: 230 ✭✭
    Re: Cheap Chinese inverter reviews?
    Third group:

    Those with a lot of education and experience who are perfectly willing to share same with others so they won't have to go the trial-and-error money-wasting route buying junk equipment to find out the hard way if solar is a viable option for them.

    ;)

    Coot, yes that is what these forums are all about now isn't it? But IMO you have to be in group 1 before you even come to these forums. I'm not suggesting I went into solar a complete novice thinking I could figure it all out on my own, I did have plenty of electrical experience before, knew how to wire a house, build amplifiers and radios on memory alone. Was also an astronomy fanatic so the vital stats of the sun, planets and heavens were no stranger to me. Perhaps it was all my prior knowledge that made me complacent in my choice of equipment. Knowing exactly how to put something together does not help you choose the correct brands unfortunately...
  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    Cariboocoot.. If you are referring to the Invtak inverters that are 6kw on 12 v or their 12 kw on 12v as being of poor design and quality. You are very wrong.. These are low frequency inverters and stand next to Victrons in quality.... Their weight is a bit of a giveaway.. the 6kw weighs about 40kg and the 12kw weighs about 80 kg from memory..When I first ever saw one I was amazed at such a quality item from China.. I sent them many questions mostly about why multiple 12v inputs..??? Obviously it was because you would never get cables big enough to connect to carry 500 pls amps on one reasonable terminal.. Iasked why not go to 48v ? make a lot more sense. . I not sure if it a language problem but their impossible to understand answer was people preferred 12v???????
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?

    John;

    No, not that brand specifically but the principal is the same. From an engineering POV it makes no sense to have multiple high-current inputs when raising the Voltage makes everything easier and more efficient.

    As for the company's answer of "people prefer 12 Volt" ... well they're asking the wrong people.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?
    CALLD wrote: »
    Perhaps it was all my prior knowledge that made me complacent in my choice of equipment. Knowing exactly how to put something together does not help you choose the correct brands unfortunately...

    Exactly. A little bit of knowledge can be a dangerous thing they say. When i was in the military way back, having taught myself to solder as a boy, made me among the slowest in the group to master milspec standards as id learn too many bad habits along the way. It was all about massive cleanliness, and absolute stillness while the solder cooled. Whereas i was like she'll be right. But you could see the difference if you looked under the microscope.

    And i agree about brands. That was the hardest part of our install, was figuring out what the industry standard components were, and sourcing them. I still struggle with this. For instance the common US trade conduit adapters, EMT, metal load centers, metal trunking etc, none of that is available here. Everything is plastic and flexible conduit. I had to actually bring the outback inverter back in my suitcase, as the price they charge her is extortionate. The only thing i was able to get from the local hardware store was the ac wiring, and some nuts and bolts.
    john p wrote: »
    I sent them many questions mostly about why multiple 12v inputs..??? Obviously it was because you would never get cables big enough to connect to carry 500 pls amps on one reasonable terminal..

    Multiple inputs is a common trait of china inverters. As is internal fusing. The Kosun unit that i inspected had a bank of parallel 20A blade fuses. Read my post about AIC to see why blade fuses in an inverter are stupid. And parallel fuses, that's just nuts. Variation in fuse manufacture will guarantee one fails before the others, leading to a cascade failure. Worse is internal fusing leads to complacency and no external fusing, and you have a disaster waiting to happen. These units should not be allowed to be imported.

    The same applies to multiple input terminals. They supply 2 pairs of 16mm cables with a 4kW inverter, and think that's cool. It's not. As a rule you should never parallel wires to achieve ampacity. Same reason: manufacturing variance will mean one wire carries more load than the other, and therefore any parallel conductors must adhere to the rule that each conductor must be fused separately , or, each conductor alone is ampacity rated greater than the fusing rating. Sorry but I can't trust a company that makes these sorts of design decisions, no matter who recommends them. But my opinion is essentially worthless in this game. What counts at the end of the day is what ETL/UL have to say. If ETL says that that China gear passes, then I'll be glad to revisit the above.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    Cariboocoot im not saying what they do is what I would even consider doing.. I have always used the rule of toe 12v per 1kw..And prefer not to use cables above #4.. mostly because the special press needed to put terminals on correctly .
    Now they say people prefer 12v will they are a very successful company in sales. So their doing something that is obviously what customers want...Idont think they are asking the wrong people unless you mean they are not asking people that know its better to go to higher voltages above 12v..But are those people their customers?? IF not then they dont care their opinion.

    As for internal fuses you would not believe how many I have seen from so many manufacturers using multiple parallel internal fuses...Every one I have used in every install including my own has them..... And to my so far amazement not one of them has ever blown a fuse.. Some now 4 yrs service 24/7. What does this all mean??"The sky is not falling"
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?

    John;

    It's not really a matter of whether or not it will work or even work reliably and safely: all engineers know there's more than one way to do anything. It's more a matter of engineer best practice, which multiple DC inputs and high Wattage from low Voltage are not.

    As for what sells ... well most people buy based on what they know, which too often isn't enough. Offer the average Joe a choice of 2kW 12 Volts and 6kW 12 Volts and his lack of understanding will cause him to believe the 6kW must be 'better' even though from an engineering POV it is worse.

    Many companies sell all kinds of products dependent on this sort of lack of understanding. The major criterion for so many purchases is 'price point'; a term which sends shivers up the spine of an engineer.

    Around here we try to encourage people to look beyond that and see the real value in a product. Or indeed lack there of.

    Having once many years ago burned the palm of my hand on a starter button for a 6 Volt Oliver tractor, I understand the practical implications of higher Voltage/lower Amperage very well. :D
  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    This makes me as guilty as the others that dont know what they should buy.. I bought my 2000x12v inverter mostly on price.It was less than 1/4 the price of anything else from a major manufacturer.. Sure I will never be using it at anywhere near its rated output.. And feel it is most likely to be a good buy.. TIME WILL TELL .. Stay tuned.
    And yes of course it has multiple parallel internal input fuses.. but only one set DC terminals..My guess rated at about 800w continuous... The supplied input wires would overheat first..#8 aprox.
  • jimindenverjimindenver Solar Expert Posts: 59 ✭✭
    Re: Cheap Chinese inverter reviews?

    I went 12v because my RV is 12v and adding a second set of batteries for a 24v inverter isn't going to happen as I have no room.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?
    I went 12v because my RV is 12v and adding a second set of batteries for a 24v inverter isn't going to happen as I have no room.

    Yes. Different issue, though. As I so often point out an RV application is one of the reasons why you'd stay with 12 Volts.

    But the contention is not over using a 12 Volt system, but rather the amount of power the system is expected to supply. As that goes up the lower Voltages have more trouble. A 2kW inverter on 12 VDC at it's maximum is still only perhaps 200 Amps total, which can be managed. And usually that is not a continuous demand.

    But expecting 12kW or even 6kW from 12 Volts ... Really it is expecting too much. It is not practical, of dubious safety, and certainly not sound practice. Just do the math and then look at available wire sizes Ampacity.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?
    zoneblue wrote: »
    Worse is internal fusing leads to complacency and no external fusing, and you have a disaster waiting to happen. These units should not be allowed to be imported.

    Interesting point. Both my Xantrex PROsine 1800 watt and 1000 watt inverters have their DC inputs internally fused. Yet they are very highly rated, CSA and UL approved, as well as, according to what I read somewhere in Xantrex info a while back, approved for used in Life Flight operations to power medical equipment.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?

    Its obvious why manufacturers selling largely to non technical market segments would want to add internal fusing. Without it theyd be on the phone the whole time, doing RMAs for blown inverters because their customers dont understand how or why an inverter should be correctly wired, fused and installed. They figure fusing covers their butts. In the mobile market this is especially so.

    But folks, here we are talking (mostly) about residential applications. This is what is known as 'hardwire'. Inverters will be UL listed for either hardwire or mobile/marine. The likes of the Prosine and Samlex (edit:most of them) are not hardwire inverters. The presence of AC receptacles is the usual clue there. These inverters are sometimes pressed into service for hardwire, but that doesnt make it right (or wrong depending on how its done).

    Hardwire inverters do not contain internal fusing. This is because the requirements of that fusing are pretty demanding, and this becomes clear to you the first time you heft a F series Carling breaker in your hand. Around 3lbs, and carrying an UL listing of its own. The price of that breaker would almost double the price (and weight) of some china inverters. A T-class fuse will set also you back $45, and adding one to a budget inverter is still going to blast the product out of its price point. And yet these are the correct and approprate devices considering the energy resources the inverters are connected to.

    UL listing is incredibly rigorous, and a key part of your protection as a consumer, and home owner. At the end of the day we each have to make decisions about what laws we follow, what reassurance we need for our familys safety. Even though our place is minimally insured, the fact that most insurers require UL listed hardwire for off grid power gear, is sufficient reason to spend the extra 1K or whatever to do things properly.

    Many may get away with all sorts of folly for long periods, but life is a numbers game. Looking back when a tragedy occurs, a person would feel pretty awful if the thousand bucks they 'saved' was the cause of loss of life or property.

    And... in a public forum, belonging to a respectable RE company, we can and should only be advocatiing, compliance with relevant regulatory guidelines, and industry best practice.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • PhotowhitPhotowhit Solar Expert Posts: 4,276 ✭✭✭✭
    Re: Cheap Chinese inverter reviews?
    zoneblue wrote: »
    But folks, here we are talking (mostly) about residential applications. This is what is known as 'hardwire'. Inverters will be UL listed for either hardwire or mobile/marine. The likes of the Prosine and Samlex are not hardwire inverters. The presence of AC receptacles is the usual clue there. These inverters are sometimes pressed into service for hardwire, but that doesnt make it right (or wrong depending on how its done).

    Both the Prosine and the Exeltech that I referred to, either can be hardwired or come in versions that are hardwire only. FWIW Prosine's aren't particularly cheap. Prosine's come in 2 versions hardwire or outlets and they have in the past carried UL1741 (see attached) The Prosines don't have a provision for the DC to be in conduit so must be in a UL case for legal use in homes. I don't know if Exeltech comes with UL1741, they do have a provision for encasing the DC in conduit and have a UL rating for telecommunications.

    FWIW I think some Samlexs are also designed for hard wiring. Though I'm not as familiar with them.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Cheap Chinese inverter reviews?

    Position of the fuse or circuit breaker is not relevant to function. It can be inside the inverter or by the battery or any place in between, on either positive or negative wire. Where it is placed depends on practical/pragmatic considerations. If the fuse is inside the inverter and hard to get at, that's a pain for replacement. That's all. It's not the same issue as having multiple parallel DC connections/fuses. The important thing is that the circuit has the protection: including it in the design of the inverter is a fail safe against people who would skip it altogether. Having a more readily-accessible fuse or breaker outside may be redundant functionally but it can make it easier to deal with over-load conditions (providing the external protection is of slightly lower Amp value so that it is triggered first).

    Yes, some Samlex inverters can be hardwired. In fact there are many inverters out there which have the choice of outlet/hardwired. But the output is another matter from the input.

    Did anyone ever say this stuff was simple? If so, they were lying. :D
  • john pjohn p Solar Expert Posts: 814 ✭✭
    Re: Cheap Chinese inverter reviews?

    I agree with Cariboocoot . Its a good idea to use some form of external current limiter with a lower rating than the internal fuse/s before the inverter.. One small problem it means you have to open the inverter in many cases as its often not stated in the 3 page chinglish manual.This means you may have now voided the warranty. ??

    Now for what almost no one agrees with me about. And the usual reasons its not good to do are what I believe are the reasons to do it..
    Using a shunt instead of a circuit breaker or fuse offers many advantages in protecting inverter /wiring from inverter/wiring fault.... Its very easy to connect a millivolt meter across the shunt and see what current draw is usual and its then easy to see if something is a problem if that reading is not usual.. A circuit breaker or fuse will never tell you of a possible device failure.

    If you dont like this idea thats ok no need to tell me. as many already have..
  • dexydexy Registered Users Posts: 2
    Re: Cheap Chinese inverter reviews?

    One main issue I have with most of these inverters is that they don't have an adjustable low battery cut out, so they always bleed your battery to dangerous low voltage levels before they cut out, which will in-turn reduce the life of your batteries by a lot of years.
  • BB.BB. Super Moderators Posts: 26,870 admin
    Re: Cheap Chinese inverter reviews?

    Having an adjustable low battery cutoff is nice--But for lead acid batteries, the voltage cutoff is rather "fuzzy" at best for accuracy (hot/cold batteries, heavy vs light loads, age, etc.).

    There are battery monitors that have alarms--But even battery monitors have their accuracy issues too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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