Thread: VFD advice please

Originally Posted by rev

I'm considering buying one of these VFDs to run a 3000w 3 phase motor from a 15A 240V supply.

http://www.ebay.com.au/itm/261584702...%3AMEBIDX%3AIT

http://www.ebay.com.au/itm/181647798...%3AMEBIDX%3AIT

My question is whether this maker's power ratings are reliable, or are they quoted rather optimistically? In other words, will the 3kw 13A rated unit actually drive a 3000w motor to its full capacity? If so this is the unit I would buy to save some money. First hand knowledge from people who have used such a VFD would be greatly appreciated.
The 4kw unit should be able to do the job but might be unnecessary; besides, it is rated for 16A (though I would need to drive 3000w and therefore shouldn't risk overloading the separate 15A shed circuit)

What is it that you intend to drive? The characteristics of the load being driven are quite important.

It is for a cyclone blower, 15" impeller.

Originally Posted by rev

It is for a cyclone blower, 15" impeller.

The VFDs you looked at will be fine for that.
I would program it with a soft start and slow down.

Thanks BobL.
I take it that means you believe this makers power ratings are 'truthful'.

Originally Posted by rev

Thanks BobL.
I take it that means you believe this makers power ratings are 'truthful'.

Yep - they seem to do what they claim.

A 3kW motor on a conventional 15" impeller connected to ducting and machinery is not going to pull 12.5A @240V @50Hz anyway.
The resistance or back pressure means it will only draw about 9.5A (i.e. 2.3 kW)
It may reach closer to 12A if you run it at 60Hz.

Also note if you run the motor/impeller with no resistance (i.e.no ducting and/or cyclone connected) the motor may draw more than 3kW and damage the motor.
The VFD will probably protect itself and the motor since it can nobly sustain an over current for a short period of time before it turns itself off.
These VFDs are very good like that.

Great! That gives me confidence. Cheers

That was the original VFD I supplied with all Clearvue Cyclones and we only changed due to a disruption in supply that lasted some months and threatened to halt sales. The big drawback with that VFD is no rotary control for speed and technical support is/was non existent which was no good to us when we had to advise and fix problems in the field. The Powtran VFD as used now has instant factory support direct from the manufacturer in China which helped immensely when problems occurred. The Powtran is a far better product in that it is way more versatile in lots or areas.

Thanks Chris.
Do you have a link for the one you mention, and a price please? I just googled 4hp 3kw Powertran VFD. The results don't identify the word 'Powertran'.

Originally Posted by Chris Parks

That was the original VFD I supplied with all Clearvue Cyclones and we only changed due to a disruption in supply that lasted some months and threatened to halt sales. The big drawback with that VFD is no rotary control for speed and technical support is/was non existent which was no good to us when we had to advise and fix problems in the field. The Powtran VFD as used now has instant factory support direct from the manufacturer in China which helped immensely when problems occurred. The Powtran is a far better product in that it is way more versatile in lots or areas.

I agree that there is no official support for the Huanyang VFDs but we do have a pretty good collective knowledge of this product on this forum.
OK its not official support but it is a form of support

The Huanyang VFD can also be obtained with a potentiometer on the front panel, it's just a matter of looking around and it takes only a few minutes to hook up an external pot anyway.

Chris I would be interested to know some specific about the "way more versatile in lots or areas".

OOPS...should have been Powtran (not Powertran)!...I'll google again.

Thanks also, BobL

Bob, I can't sell something that does not have official factory support, the customers would go nuts if I told them to ask on a forum on how to sort out a problem. Nor can I go and start modifying or ask the customer to modify a new product that as supplied should do the job.

The keyboard can be remotely mounted using an ethernet cable, the Huanyang needs the owner to make the cable

The program in the VFD can be downloaded into the keyboard.

That keyboard can then be used to program another VFD uploading from the keyboard.

Using that I could send a keyboard to a customer and he could upload any program changes I had made or he needed.

Up to ten profiles for different machines can be programmed in and selected from the keyboard for ten different machines

It is a very versatile unit, way more than the Huanyang but the Huanyang still does the job and I never heard of a failure of any we supplied.

Thanks Chris,
I was thinking more about the functional operations of how a VFD controls motors, but it does sound very versatile especially for generic customer support.

Rev, a CV 1800 swinging a 15 inch impeller works at under ten amps with one gate open in a 150mm duct and is down around 7-8 amps with all gates closed. These are not exact numbers as it is quite a while since I checked them but it is in that region. At start up it does not exceed 15 amps and only gets up near there momentarily. A 15" impeller requires 3.25 HP which is near enough that a 3HP motor will do it but CV took the view that it is a marginal thing so they supplied a 5HP motor in the US. When the US (Leeson) motor became unavailable to us because legislation changes in the US caused them to stop making it we supplied a 4KW Teco Motor. Incidentally it is very hard to find a VFD that will drive a 4kw/5HP motor from a single phase supply and to my knowledge Powtran and Huanyang might be the only ones.

This is the motor I have, so the 3kw 4hp Huanyang unit should suit, right?

IMG_0033.JPG