Cheap 3 phase inverters.

[Andrew TinsleyParticipant @andrewtinsley63637]

I have been looking at single to 3 phase inverters, for a friend of mine. I was somewhat staggered to find 0.75 kW inverters at sub £90 prices.

Doing a search on the forum, turned up a few people that have used cheap inverters without any problems. Considering that the quality suppliers in the UK can be priced at near three times the cheapo prices, I am somewhat tempted. I don't have any problems with setting up an inverter, even if the manual is in poor Chinglish.

What are peoples opinions of such cheap inverters? More to the point, has anyone had any real reliability problems with such units?

Andrew.

[Andrew TinsleyParticipant @andrewtinsley63637]

[Alan Waddington 2Participant @alanwaddington2]

Iv'e got an expensive one on my lathe ( bought secondhand so not so expensive) and a cheap chinese ebay special running my mill, they both perform perfectly well……how long they continue to perform, only time will tell ? After i bought the chinese one, someone posted a link to here….https://inverterdrive.com/….had i not already bought the one from ebay i would have probably used them instead, as the prices are very reasonable. ( mill inverter is 5hp)

[Chris Evans 6Participant @chrisevans6]

I have had a cheap (£90) Chinese VFD inverter running my 2HP Bridgeport mill for around 4 years now with no problems.

I run my 3 HP lathe from a static inverter and did try to run the mill from the static inverter as well but it did not run for more than a few minutes before stopping. The cheap VFD was set up for me by a friend who understands the "Chinglish"

[Andrew TinsleyParticipant @andrewtinsley63637]

Thanks for your responses,

Even if a cheap one expires in a few years of light use then it would look as though it is worth the gamble. I notice that the best warranty on UK reputable inverters is 5 years. For light use, I suspect that the cheap inverters will last that long. If they don't then buying another will still be cheaper than buying a reputable make.

Am I on the wrong track here, anyone with nightmare stories of cheap Chinese inverters?

Andrew.

[SillyOldDufferModerator @sillyoldduffer]

VFD's are electronics and, as we all know, prices of such items start high and finish low. Once the initial design and development is complete, and the initial investment recovered, electronic items can be knocked out very cheaply.

There's some risk that counterfeit components might have been used, but that can happen to 'quality' makers too. (Air Force One was fitted with counterfeit aircraft parts, and many reputable manufacturers are caught in the Kobe Steel Scandal. )

An expensive VFD might have higher rated components, be better cooled, have improved software, good EMC properties, support, and a more effective enclosure. Or you might be paying for an out-dated model with a fancy brand-name.

True story. I once bought a cheap wireless router from Tesco's. It turned out to contain the innards of a much more expensive brand-name product. The only difference was that Tesco's version had all the bugs fixed. No-one ever bothered to update the brand-name equivalent; instead they brought out a new model. Next time I bought a new router from a super-market, it was poor.

It's very difficult these days to generalise about 'quality'. You need to check rather than make assumptions. Back in the good old days many things depended on the use of good materials, skills and trade secrets. If it was any good, it was expensive. These days there's much more competition, much manufacturing has been deskilled, and there are no trade secrets. You really have to look quite carefully at what you're buying. In practice, that can be difficult, and most things are 'fit for purpose' rather than 'military grade'. In the end yer pays yer money and takes your chances.

I'd buy a cheap one and risk it. If it lasts 5 years you've won! It's very unlikely that any VFD will become an heirloom, no matter how well it's made.

Dave

[Matt Stevens 1Participant @mattstevens1]

So I would have to recommend the Siemens G110 inverter as a cheap VFD, or if you want vector control then go for a Siemens MM440.

Both these inverters are made at Siemens Congleton in the UK where I worked int he R&D department for a good ~13 years. Hi quality and tick all the boxes mentioned by Dave above.

They will not be as cheap as some of the Chinese stuff….but then you get what you pay for. Same scenario with Lathes and anything else….

[MuzzerParticipant @muzzer]

Reliability and lifetime are quite different things. A cheap biro should have a lifetime set by the reservoir of ink but may be unreliable so that it fails before the ink runs out. A missile may have a lifetime of only a minute or so but a reliability (MTBF) of many years of operating time. Reliability is about chance and probabability. So whether a cheap VFD will "last" is fundamentally a matter of whether it happens to fail in week 1 or week 101. It is just as likely to fail at either time.

There are plenty of examples of Huanyang (I assume) VFDs popping. And when I look at their design and construction, it is clear that it's not just the quality of the manufacturing that's the root cause. In contrast, the "proper" VFDs you will find in factories are designed, constructed, tested and manufactured to last. They are also used and proven in a wide range of applications. It's the difference between a hobby toy and an industrial machine.

The inverterdrive.com products are pretty competitively priced and they seem to be a pukka outfit. It looks as if you could buy a Huanyang for 2/3 the price of a Yaskawa, Siemens, Mitsubishi etc. But why buy cotton when you can have silk?

Murray

Edited By Muzzer on 18/10/2017 21:27:11

[john fletcher 1Participant @johnfletcher1]

I've wired up a few 3 phase motors and Huanyang inverters for my friends, no problems so far and that must 4 years now. I have a Yaskawa, Omron and a very early one supplied by RS about 30 years ago (programmed by dipswitches) mine are all preowned, as the used car salesman says and never had a problem with any of them. Why on earth people continue to knock Chinese products I'll never know, is it our continued EMPIRE prejudice, I ask. Go to Warwick exhibition today and see if you can find a new British made product on sale, it might be badge engineered. The same mentality prevailed in the early 1950's regarding Japanese motor bikes. Possibly some of the more expensive inverters are also out source in PRC or Singapore like the Dyson vacuum cleaners. If you think it will do the job just buy it. John

[Chris Evans 6Participant @chrisevans6]

Huanyang, thanks for the reminder of the name saves me looking for the name on mine. As said above one of these has powered my Bridgeport for a few years now, the friend who wired it for me has five or six of them running his various machines and no issues. I am in my 70th year and whereas 50 years ago when I made my living on the tools things where bought to last a lifetime these cheaper units will most likely do just that. If it where not for the likes of ARC etc importing stuff there would be fewer people enjoying our hobby. Go for the Chinese VFD mine arrived in less than a week.

[mark smith 20Participant @marksmith20]

Posted by Matt Stevens 1 on 18/10/2017 19:49:54:

So I would have to recommend the Siemens G110 inverter as a cheap VFD, or if you want vector control then go for a Siemens MM440.

Both these inverters are made at Siemens Congleton in the UK where I worked int he R&D department for a good ~13 years. Hi quality and tick all the boxes mentioned by Dave above.

They will not be as cheap as some of the Chinese stuff….but then you get what you pay for. Same scenario with Lathes and anything else….

I have a Siemens mm440 on my southbend cant fault it been perfect and easy to set up ,even though im totally ignorant of electronics. Bought brand new off ebay for £50. All my invertors have been off ebay and brand new and ive never had to reform any capacitors due to lying on shelves somewhere .

The last one i bought for my Alexander mill was a Toshiba Tosvert (the bright red ones) which was a bit more expensive but £100 cheaper than from shops. The seller was in Manchester but the invertor was sent from a Toshiba inverter dealer in Brescia Italy.

Regarding Chinese built stuff ,ive found its the quality of the components used on the circuit boards of stuff that usually fail. When they use Japanese components you dont tend to get as many problems. Or like the mini mill from Warco ive had for years ,they used a kb electronics board which has never failed in over 10 years.

An example of cheap components is set top boxes like Humax etc… ive had a few and they stopped working after a couple of years but simply replacing the bulging capacitors on the main boards. with reliable Japanese brands have got them working perfectly again.

Just replaced a hard drive in my Bt youview box ,for some reason the hard drives fail despite being branded western digital .(not sure why these fail)

[OldironParticipant @oldiron]

I have 2 HuanYang 1.5Kw Inverters. 1 One my Boxford lathe and one on my Ajax mill. Had both for about 1 year and they run like a dream. Under £100 each. I did splash out £55 each on remote control boxes. No problems setting up at all.

[Bill DawesParticipant @billdawes]

I have always puzzled over the prices of some of these inverters advertised at several hundred pounds.

I say this because not too long ago I bought (through work I admit) a WEG inververter for my lathe and it did everything I needed and more. WEG are a high quality brand and well known in the electric motor world. Can't remember the exact price but it was less than £100, but as I say that was trade price.

Bill D.

[Bill DawesParticipant @billdawes]

PS working in my field of industrial fans we buy a lot of motors, fractional power to several hundred kw.

Most of the well known brands these days, Siemens, ABB, Brook etc have a 'budget' range of motors made in China.

To be fair, not been to China but talking to motor reps that have, describe very modern state of the art factories that they deal with.

Bill D.

[MuzzerParticipant @muzzer]

I work for a Chinese company and have been all over China (and the Far East) during the last 20 years working with suppliers, manufacturers and customers, so I think I can talk with some authority. I also have 35 years working in product development for volume manufacture – mainly VFDs and power electronics, mostly made in China these days.

When I look inside a Huanyang VFD I know what I'm looking at and I can also tell you that you won't find them in any reputable factory over there. They simply wouldn't outlast any warranty period. It's not a matter of where they are made, it's about how they are designed and constructed. A "cheap" range from a reputable company, made in China is going to be pretty good compared to some of these hobby grade things.

Murray

[OldironParticipant @oldiron]

Muzzer I will agree with you about industrial use but how often & how long do we as hobbyists use them for.? I bought mine from a German supplier with a 2 year warranty. I use mine maybe 3 hours a week so I hope they will pass that time period.

regards

[Andrew TinsleyParticipant @andrewtinsley63637]

Hello Muzzer,

I don't have a clue if the cheapo VFDs are Huanyang or not. It would be interesting to hear your take on the reputable Chinese makers. Who are they and how do they compare with "European" (?) brands, assuming they are not made in China.

Like you, I have been to a good few parts of China and seen good and bad manufacturing setups, so I don't have any problem per se about buying Chinese gear.

Regards,

Andrew.

[Neil WyattModerator @neilwyatt]

The IMO Cub inverters from have vector control are affordable and have a 5-year warranty.

The only problem is that after it has worked faultlessly for five years you start wondering if it is now due to fail…

Neil

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