Experience of Chinese VFDs?

[Mike CrossfieldParticipant @mikecrossfield92481]

I am in the market for a VFD to drive a 3/4 hp 3 phase motor. I want to operate down to low speeds, maybe down to 10Hz. So I need a VFD with sensorless vector control(SVC) in order to improve low speed torque. I am very tempted by some models of Chinese VFDs which on paper have all the right features. Examples are from the SU600 range and the NFLINX 9600 range. However, these are typically 1/2 or even 1/3 the price of products from premium suppliers such as invertek, Bosch, Mitsubishi etc. and I wonder if they really are equivalent when it comes to performance.

So I would be very interested in hearing from anyone who has experience of Chinese VFDs, particularly using SVC to enhance low speed operation.

Mike

 

 

[Andrew SkinnerParticipant @andrewskinner94774]

I’ve got both cheap and expensive VFDs. Roughly speaking, the expensive ones do seem better at handling low speeds. Also, the support and manuals are better, so that’s what I’d go for.

[Mike CrossfieldParticipant @mikecrossfield92481]

Thanks Andrew.  That’s helpful.

 

Mike

[old martParticipant @oldmart]

There are regular threads from members not being able to understand the instructions for their bargain Chinese inverter drives. I f you pay more, about £160, you can have a British made Invertec Optidrive with a “quick start guide” from The Inverter drive Supermarket. The guide shows how to program the unit and connect remote controls. The controls on the drive are not intended for anything other than setting up. with remote controls the drive can be safely kept out of harms way.

 

https://inverterdrive.com/group/AC-Inverter-Drives-230V/Invertek-Optidrive-E3-750W-1ph-3ph-IP20

 

 

[peak4Participant @peak4]

If you’ve not already sources one, and can find a suitable motor, the other possibility is to use a slower one, say 6 or 8 pole, and run it up to a 100Hz to get higher speeds

Bill

[Mike CrossfieldParticipant @mikecrossfield92481]

Thanks Bill

I’ve already gone with a 6 pole motor, but I want to extend the low end of the range as much as possible.

Mike

[HuubParticipant @huub]

I tried (the cheapest I could find) a €30 1 kW VFD to run the mill 600W AC motor. I took the “risc” because the motor will be replaced by a 1kW servo motor once the mill is capable of milling steel. That VFD has a decent manual and more than enough functions to keep me busy.

If running on low RPM with “full” torque is important, consider an AC servo. In the 1kW range they (T3d, AliExpress) are affordable and do a decent job.

[Mike CrossfieldParticipant @mikecrossfield92481]

Thanks Huub

[Mike CrossfieldParticipant @mikecrossfield92481]

Thanks old mart

what is not clear to me is whether the Chinese vds are basically as good as the branded items, but let down by incomprehensible documentation, or whether they have fundamentally inferior software.

Mike

[old martParticipant @oldmart]

I think the Chinese instructions are aimed at trained electricians and electrical engineers, so are somewhat difficult for the average person to understand. As for the life expectancy, that will be a matter of chance, with a higherpriced industrially rated one there will be a proper guarantee and backup.

I bought a six pole motor and a Schneider Altivar inverter and used the”quick start guide” for the Tom Senior light vertical mill, running from 25 to 75 Hz together with the four speed belt drive which is essential to not loose power at low speeds.

[Dave WoottonParticipant @davewootton]

From a bit of practical experience, I fitted a Chinese VFD from Ebay to a friends Harrison L5 a couple of years ago. Despite having quite a bit of practical experience of fitting VFD’s at work (Mitsubishi) , but far from being an expert, I puzzled over the instructions for quite a while trying to get the thing working on momentary push button control and not by the keypad, one elusive parameter stopped it working, eventually more by luck than judgement, and some help from Youtube achieving success. The inverter worked fine and was satisfactory for a year or so, then it proceeded at varying intervals to forget the programmed parameters and return to factory settings, not a problem as I lived less than a mile away and could pop in and re enter the settings. When I was about to move several hundred miles away he decided to buy a new inverter as he was not happy with re programming it. He bought one of the cheapest from Inverter Drive Supermarket, which as stated in earlier posts comes with a quick start guide, a revelation in ease of programming, fitted, wired and programmed within the hour and been working perfectly ever since (about eight months so far). I know of other Chinese inverters that have worked faultlessly for years, this one was probably just a Friday afternoon model, but the clear instructions from Inverter Drive Supermarket and ease of setting up and programming is something to bear in mind. Hope this helps.

Dave

The replacement IDS drive (can’t remember the make offhand) runs far quieter than the Chinese one which produced a high pitched squeal in the motor itself.

[mark costello 1Participant @markcostello1]

I bought a Huanyang vfd and could not get it to hold the settings, SIL is experienced with electrical stuff and computers and it would not stop reverting to useless settings. Got a prompt refund but cannot buy another one.

[Mike CrossfieldParticipant @mikecrossfield92481]

I think I am now convinced that I should avoid the Chinese VFDs!

Many thanks to all those who replied.

Mike

[Robert Atkinson 2Participant @robertatkinson2]

Another issue with low cost drives is a lack of EMC filtering. Unfortunatly interference filters cost money but are not essential to the basic operation of the drive and many users are unaware or don’t care if they cause inteference to outher people.

From the, admittedly few, I’ve seen the low cost drives from the far east seem to use lower quality components and construction. Electrolytic capacittors in particular are example of you get what you pay for. Cheap ones don’t last. Even some branded ones have rated lives of only 1000 hours.  They are the primary cause of the failure of modern electronics of all types.

Robert.

[southernchapParticipant @southernchap]

There are Chinese VFDs and there are Chinese VFDs.

I’m not convinced that a VFD with SVC that costs £160 new, wasn’t made in China. Go take a look at the cost of ABB, Mitsubishi, or Hitachi new VFDs.  They don’t cost £160.

Delixi (a Chinese manufacturer) VFDs cost around £400 new.

Like any product, from any country, you buy cheap, you get cheap

[Huub]

On Huub Said:

If running on low RPM with “full” torque is important, consider an AC servo. In the 1kW range they (T3d, AliExpress) are affordable and do a decent job.

An article in ME&W on understanding and using this kit would be nice.

[HollowpointParticipant @hollowpoint]

I’ve never used a Chinese VFD so can’t help with that. But I would just like to add how incredibly happy I have been with Invertek drives. I’ve had 3 of them now and they have been flawless in performance, easy to set up and not too expensive either. The cherry on top is that they are made in the UK!

[southernchap]

On southernchap Said:

There are Chinese VFDs and there are Chinese VFDs.

I’m not convinced that a VFD with SVC that costs £160 new, wasn’t made in China. Go take a look at the cost of ABB, Mitsubishi, or Hitachi new VFDs.  They don’t cost £160.

Delixi (a Chinese manufacturer) VFDs cost around £400 new.

Like any product, from any country, you buy cheap, you get cheap

I agree.

If you want cheap and cheerful, they’ll sell you that; if you want better stuff, ditto. In the former category, I have many gadgets and tools that I couldn’t have afforded/justified otherwise.

Example – 6ft transmission jack, £90 delivered. Looking at UK steel prices, I could only just buy the raw bar stock for the ram for that money.

[Author]

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