|Clive Brown 1||17/10/2019 11:54:44|
|399 forum posts|
I'm thinking of buying a cheap (new, £50ish ) VFD from Ebay. Do these items, listed as "unbranded" generally come with programming instructions or is it a case of buyer beware, any experiences?
I've tried emailing the UK? suppliers but no definite answer as yet.
|Kevin Murrell||17/10/2019 11:56:56|
|32 forum posts|
Mine was from eBay. Works perfectly. The 'instructions' are a single large sheet of paper with all the programmable settings defined. Takes a bit of looking at, but it's all there.
|bill ellis||17/10/2019 12:20:10|
|71 forum posts|
I have 2, each from different eBay suppliers, as above they come with a single double sided sheet detailing the configuration parameters and how to set them. Looks complicated at first but really is a doddle.
|414 forum posts|
Mine also came with a 1 sheet instruction "manual" No problems.
|Paul White 3||17/10/2019 14:06:57|
|94 forum posts|
can anyone comment on the use of a VFD rated at 1.5 kW on smaller motors, of 1/2 HP RATING.
|Clive Brown 1||17/10/2019 15:41:26|
|399 forum posts|
Thanks for responses, seems reasonably encouraging. I've now had further replies from two Ebay vendors. They each say that they will ask their supplier, presumably in China, if instructions are included. I'd have thought that they could at least opened a box and looked. Doesn't bode too well for prompt product support if needed.
Re Paul White's question; I'm no expert but, within reason, I don't think a VFD rating somehat greater than the motor power will cause any problem. The VFD parameters may be settable to the motor size.
|Martin Connelly||17/10/2019 17:28:14|
1211 forum posts
Paul, if you have a 1.5kW motor that is not fully loaded it will seem like a small motor to the VFD. It would be a poorly designed VFD that could only be used with fully loaded motor running at max rated power.
|not done it yet||17/10/2019 19:57:01|
|4477 forum posts|
It is likely that a grossly oversized VFD would not recognise an overload for a small motor and let the smoke out of it. I would expect that double might be OK, but 4 times might be OK until a fault occurs... Ie. A 1.5kW VFD would see an overloaded small motor as a normal-size loaded motor.
Edited By not done it yet on 17/10/2019 19:57:53
|Michael Briggs||17/10/2019 21:02:31|
|183 forum posts|
With the motor parameters correctly set you should get full motor protection.
|Paul White 3||18/10/2019 13:10:04|
|94 forum posts|
Thanks to all respondents , your comments were most helpful .
i had not wished to high jack the thread but
the OP question is pertinent to where I find myself.
Michael Briggs post takes us full circle- does the £50 unit have the set up spec. to allow the
use of small motors.
If Clive ever gets a "manual" I Would be pleased to hear.
|David Jupp||18/10/2019 14:25:32|
|723 forum posts|
Note that the 'understandability' of manuals supplied with VFDs does vary widely.
Some are poor translations or include poor use of English.
Some assume you have lots of technical knowledge, but don't give any basic guidance - or offer a huge wealth of settings and just confuse you.
One advantage of major brands is you can have access to e-mail or telephone based technical advice of a high standard included in the purchase price.
For any VFD with a brand and model number, you should be able to locate the manual on line and then decide if you could work from it.
|old mart||18/10/2019 15:10:48|
|1512 forum posts|
The possible difficulty with getting the programming right, they all seem to be different, and not intuitive either caused me to do some research into many different types before getting one.
I bought one from this firm: **LINK**
They are not the cheapest, and VAT is added to their prices, but their own guides in pdf form make the wiring and programming so much easier.
|john fletcher 1||18/10/2019 16:53:03|
|580 forum posts|
If the parameters are set correct no problem using a small motor with a "large inverter". If the inverter for £50 or so is a Huanyang make, and by the appearance it is, I have a program/setting list which I have used for my friends and which you can have a copy. I wish to add, I'm no expert at all, if I can do it I'm sure you will.There appears to a lot of mythology regarding these devices, most of the facilities available are not applicable to the hobby/home workshop users, so just forget about them and ignore them. I think it is good to get away from single phase motors,I know they have been the work horse of the Model Eng. workshop for many years but things have moved on .Some of the currents settings will need to be adjusted/altered for a smaller motor, but once you get the hang of it, as always, you will kick yourself its so easy. As the control voltage is low. it is also easy to make your own control box to give F&R, jog, and speed, unfortunately Maplins have now gone. Little toggle switches and 10K ohm pots are available on the net.Finally, there are some excellent videos on youtube on inverters programming. John
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.