VFD documentation, almost useless

I am fully aware of the 'you only get what you pay for' expression relating to purchasing cheap tools and equipment. I recently bought a VFD off Amazon mainly because I needed it quickly and my order placed very late in the afternoon arrived noon the next day. I could have got one from one of the respected well known UK suppliers but I imagine the lateness of me phoning them and the cost of next day delivery (even if it was possible to arrange) would be at a significantly higher cost than the Chinese cheapie now driving my lathe. (It cost £64 for a 2.2KW unit)

There is a downside to this bargain VFD, Its not quite plug and play!

Documentation accompanying many Chinese manufactured products has for a long time been known to be of poor quality, typically bad translation with spelling mistakes and often serious error and omissions. This VFD came with a small stapled booklet which is virtually all text (well tables of all the parameters etc) plus three diagrams, one of which is this one, I've done my best to enhance the contrast and fit the image to the available resolution on this site. The diagram seems to have been printed in grey and black ink with scant regard to registration and even less regard for accuracy.

Unusually there is not the usual 'quick install' or wiring guide and no views of the physical terminal blocks so the unsuspecting end user is left to their own devices. Being accustomed to VFD's in general I was able to connect the mains input and the three motor phases so was soon able to run the motor with the VFDs own panel. The fun starts when one wants to connect a remote pendant when the supplied diagram is not much help.

I was able to work out and get the remote controls operating and have no complaints about my purchase now but I just wanted to point out to anyone on here that its sometimes spending a little more (probably double in my care) to get a recognised brand of product that comes with support.

Ian P

Edit, apologies for somehow inserting the image twice

Edited By Ian P on 12/04/2023 17:34:49

Bad luck with the inverter instructions, you may be able to get help from forum members on wiring and programming it.

I have tried for years to get people to do research on these drives before buying them, but low prices are a big factor. Have a look at thes 1.5Kw domestic mains powered inverter from The Inverter Drive Supermarket. Look at the "quick start guide" they include for many of their products, the guide makes it very easy to wire and programme and is worth the higher price.

**LINK**

Interesting diagram. The part that concerns me most is that the motor is shown connected to PB, U and V, with W connected to ground (earth).

That is the kind of image that perhaps you should not post online anywhere as if it escapes into the wild, it could have consequences.

The instructions for a VFD are often a pretty heavy read even when well written. As you move further up the range of VFDs they have more and more options to be configured which will require some appreciation of motor theory to make useful choices. They will often run a motor with very few parameters requiring adjustment straight out of the box and will probably default to using the service/commissioning buttons on the front panel. The inputs and outputs are often configurable to interface to manual controls or control systems. Often options are available to operate the drive from the various networks used for control systems and there is plenty of choice, Canbus, modbus, interbus, profinet, devicenet, control net and plenty of others. Some of these network options may be included but an option card will often be required. I notice there is an RS485 connection on the drawing so a datalink of some type is available though the protocol used would need some research. Most of us at home just want a simple button station and pot for speed control so a read up on the options available from the parameters for the l/O ports is required.

Mike

Edited By Mike Poole on 12/04/2023 19:15:00

Purchasers should remember that VFDs (even the branded ones) are not consumer items. They are not even finished equipment. They are components that are intended to be designed and built into systems or equipment by suitably qualified and experienced persons (SQEP) aka professionals. It is the users responsibility to ensure that they are properly and safely employed. This includes com[lince with relevant regulations.

Robert.

That's correct, Robert, so many people seem to think that the controls on a VFD box are for continuous use, they are not, being only for setting up and programming. This is fine for a unit which is set up and not then touched, as most are. Proper switch and speed control gear separate from the VFD should be added. If somebody has plenty of money, they can buy a fully wired system for as little as double the cost of the parts.

From what I can see it seems the printing has slipped down with regard to the outline and terminals of the VFD outline drawing. So the top right hand 3 terminal should be U, V, W from top down.

I can see how this may lead to confusion but the VFD terminal designations do match the common format for other makes.

Ian P if you can PM me I can help correct the errors.

CS

I agree with Clive in that the terminal labelling is all out of line with the functions. Very scary ansd potentially dangerous for those not familiar with such devices. It can be confusing enough undertanding these devices even with a correct diagram. I have to say if quality control lets this slip though in the manual, what else could be wrong?

Like DC3 and clive I was concerned that the terminals and the lettering seemed to have slipped, the one that caught my eye was U,V,W, that should have been the 3 phases to the motor. PB ? Very dangerous ! May be the Mods should remove the diagram lest it be copied or used by someone with NO understanding of electrics and come to harm ? Noel

Clive
Thanks for your kind (PM) offer but I have already sorted out all teh terminals I needed to use.

Stuart
Apart from the documentation teh VFD is as well manufactured and put together as I have seen on branded products, it worked straight out of the box once I connected the mains and motor, it was only connecting the switches and pot that caused the head scratching.

DC31K, Noel
I do not think anyone who came across this image on the internet could somehow make use of it to wire anything up. Even with the actual VFD (which I did not identify) I found the diagram bore no relation to what I had in front of me on the bench.

If we think diagram's P, PB, and the UVW motor terminal connections are badly labelled then what about the mains input! I would say that since the L1, L2 and L3 are only shown (in random positions) on the diagram and not on the VFD own terminals then anyone unfamiliar with this type of product might not even be able to get mains into it. On that basis I doubt leaving this image online can be any sort of risk.

As I said earlier, its all up and running although its built in fan is driving me mad!

The fan runs all the time the VFD is powered so I intend to add an electronic thermostatic with its sensor bonded to the VFD heatsink.

Ian P