Thread: 3 PHASE TO 3 PHASE vfd

variable speed

two ways to vary speed of motor...number of poles in the motor or vary the frequency...this is what a VFD does...varies the frequency

ps...works a treat on three phase...no good for single ph

The seller also has a big range of knobs for projects

http://stores.ebay.com.au/superistor...4.l1513&_pgn=5

Originally Posted by morrisman

WHATS THE POINT OF 3 PHASE TO 3 PHASE CONVERSION

http://www.ebay.com.au/itm/2-2KW-3HP...:SS:SS:AU:1120

Variable speed.

Soft start.

Over current limits.

Probably others.

I've got quite a few of them about the place.

PDW

Originally Posted by morrisman

WHATS THE POINT OF 3 PHASE TO 3 PHASE CONVERSION

http://www.ebay.com.au/itm/2-2KW-3HP...:SS:SS:AU:1120

We have maybe a hundred or more such VFD's at work. These are all on pumps. Some are automatically variable based on conditions sensed, some are on general winery use for transfers and enable us to set flow rates. Start slow then up to full speed until the end, then slow down for the finish. Shutting a valve on a slower flow is less likely to cause a rupture in the line. Another purpose is to use the ramp up to stop hammer in the lines.

Dean

Originally Posted by PDW

Variable speed.

Soft start.

Over current limits.

Probably others.

Faster stopping
Programability
can be setup to save power/$.

When I was on the tools, I used to wonder why anyone would want a single phase VFD Toys I tell ya!!


FWIW, I have only ever seen one single to three phase VFD ever and that was in a coin weighing machine in a casino.

Originally Posted by Pearo

When I was on the tools, I used to wonder why anyone would want a single phase VFD Toys I tell ya!!
FWIW, I have only ever seen one single to three phase VFD ever and that was in a coin weighing machine in a casino.

Price has a lot to do with use.
Now that that they can be had for around $100, and the fact that $100 is not the same as $100 was 10 years ago.

Originally Posted by Pearo

When I was on the tools, I used to wonder why anyone would want a single phase VFD Toys I tell ya!!


FWIW, I have only ever seen one single to three phase VFD ever and that was in a coin weighing machine in a casino.

People want VFD's for the same reason, as in the past 40 years you would not want to buy a handheld drill with only on/off and no variable speed.

- There is probably nothing on a machine tool, that you could not do without a VFD *(or another sort of variable speed control)
- but almost everything you can do either/or better, safer or faster with a VFD

*( it just happens, that nowdays a VFD is most often the cheapest means of variable speed control