Is this cheap type of VFD worth buying?

I am thinking about using one of these VFD inverters to control a 3 phase 6 pole 3/4 hp electric motor. The motor runs at 900rpm and halving that would be useful. I have access to both single and three phase power.

The ebay listing on the UK site is : 223486597368.

The topic of cheap inverters has been well aired. I suggest you do a search on the forum. Some are dead against cheap VFDs and others claim they are just fine. I think it is a case of making your choice and paying your money.

I have gone for second hand Siemens 420 and 440 VFDs and have been pleased with the result.

Andrew.

Feeding an old motor from a new inverter can give an awfull smell.

I tried it two times before buying a new motor.

Smellfree

All I can say is that I have three second hand inverters driving three old motors. I'm very happy to have forward, reverse and speed control and NO smell what so ever. I can't think what was causing the smell, some thing must have been over heating and cooking the insulation. One of my inverters is so old it uses DIP switches to alter the program. If I had 3ph power I would stick with that and alter the pulley sizes if that is possible. John

You can get 3/4 hp and 1 hp rated known brand VFD boxes from UK based suppliers for under £100 delivered (just!). With manuals in readable English.

Look at Inverter Drive Supermarket for example **LINK** . As a very satisfied repeat customer I can testify that their reputation for good service and for taking time to sort out exactly what's best for you is well deserved. Their quick start guides are excellent and really take the mystique out of setting up.

From what I hear all the reputable UK based suppliers are a helpful bunch.

Objectively it hardly seems worth the risk of iffy quality and no service back up if it does go pop from direct import to save £45 or so. Especially as the manual is guaranteed to be incomprehensible.

No question that some of the Chinese suppliers are excellent but some still operate on the customer paid - passed QC business model knowing that the customer won't bother to spend the £20-£30 odd needed to send it back. At this range you have no way of telling good from bad.

Worth remembering that a blown inverter could take the motor down with it. Probably won't. Old school three phase induction motors are tough beasts but ...

If you are spending £200 or so to save £1,000 on an inverter welder or similar then the risk is, possibly, more justified.

Clive

I wouldn't go Chinese on an inverter. In my experience low end Chinese electricals can be very poor quality indeed and even worse can be dangerous. I would second what Clive said. I have an invertek drive which is made in Wales! One of the reasons I went for the invertek other than supporting UK manufacturing is that I would have English speaking customer service on the doorstep or at the other end of the phone. I bought mine from inverter drive supermarket and can confirm they are a good company to deal with.

Well I have two hynyaung (or however you spell it) Chinese inverters running my mill for about 14 months now and they have been absolutely fine, no complaints whatsoever. The set up wasn't difficult, plenty of info available on the web to assist in 'interpreting' the manual. There was one parameter that was troublesome but with some excellent support from here I managed to sort it without any drama. For my application it was around 1/3 of the cost of using the UK based suppliers to achieve the same result going this way and as the total cost at the time was a barrier to get the machine running the longevity wasn't a major consideration. For the work the machine has done I don't consider they owe me much and even if they pack up now (which they probably will now I have written this!) I won't be overly upset. As things stand I wouldn't hesitate to go the same route again. The only caution I would sound is buying direct from China and having them ship from there, my first attempt at that didn't go well! On the second try I used a UK based seller and they were with me in three days, cost me a little more but worth it to save a 5 week sea freight delivery and import duty etc. Overall very happy!

Paul.

As I see it, these cheap inverters are OK, if used regularly, but offer little or no motor proection. Many don’t allow the motor to be switched after the device, so protection needs to be upstream of the VFD. A simple 13A fuse will not adequately protect an overloaded motor.

But our machines should not be left running whilst unattended, so perhaps the risk is small for everyone excepting those that cannot recognise a motor overload or the very few who do, but run their machines beyond their capabilities on a regular basis.

I would not wish to store one for too long or the capacitors might need conditioning (or replacing), before putting into service, to avoid VFD failure.

I have to laugh at people slagging off chinese electronics when probably 90% of electrical devices are made there. The high end Apple £1,000 phones are made in china, as well as the rest of their range. Televisions, computers etc etc. I bought two vfd's made by huan yang for the surface grinder, set up was easy and they work fine, and did not break the bank.

I'm not against buying Chinese products in the slightest. In my day job I purchase stock from China on a regular basis. I know from experience Chinese made products vary in quality from God awful to excellent. Which is why I specifically said low end electronics.

Don't even get me started on apple. Their £1000 "high end" phone costs about £300 to produce.

I recently purchased this unit **LINK** from this well known Chinese supplier. I'm a bit of a dummy with electronics but number one son is pretty good so he wired it up and it works fine. It does of course need a control pendant to make the best of it.

I fitted a pukka one from Transwave to my Myford last year and would still go that way for a similar situation, however what prompted me to try the less expensive uint was I purchased an industrial quality linisher which had a 3 phase motor so it was either buy a new single phase with a reversing switch or go the Chinese inverter route fo less money. I could not justify the price of the UK supplied units for this situation.

My feelings are its hoses for courses !

John

A reversing switch on a linisher? I’m interested to know why. I would have thought an unnecessary addition, but I await the reason why, in anticipation of learning something new....

.

If you have overshot the mark, it lets you put material back on.

MichaelG.

Why oh why do people knock the Chinese made equipment when much of the so called made in UK is actually badge engineering. I endorse Paul Kemp and ronan walsh postings. When these cheap Chinese Huanyang inverters became available several of my friends bought them and not one has given any trouble or failed, and that must be at least 6 years ago. I was asked to reconfigure the motors from Star to Delta which was an easy job and to assist with the lathe wiring. I've never heard of inverter capacitors failing, I'm sure we would heard here or on the net if there was a problem at home workshop level.Yes, the instructions could have been easier to understand, as can other so called British makes. but we got there. John

THAT is about the only reason I could think of - apart from when something gets jammed under a poorly set stop-bar or table! The latter being less necessary than your suggestion! I wait (without holding my breath!) for a sensible reason for the reversing option.

I found the site www. inverter drive.com and was amazed at the sheer number of VFDs' they sell.

Picking one in the power range I was interested in I noticed a downloadable pdf with the installation and setting up instructions. It was amazingly comprehensive, even including details of how to wire a complete remote set of standard on off buttons, emergency stop and speed controlling potentiometer. I had been concerned about running a machine with only those rather small controls they have on the VFD box.

Main difference you get with buying British is a guarantee. I got a 4 year guarantee from Transwave when I bought mine.

Most electrical items that fail early go in the first year or two, and even the best quality items have some risk of failure.

Even if the items are identical, you have to consider what value you put one a guarantee, parts availability and customer support?

Neil