Thread: vfd questions

Your link didn't work for me. But I was about to ask that same question.

VARIABLE FREQUENCY DRIVE INVERTER VFD NEW 3HP 2.2KW 10A - eBay, Electronic Modules, Kits, Electrical, Industrial. (end time 01-Aug-10 12:04:12 AEST)

I just bought an Alan Bradly vfd from a Greys Online auction. They have a new retail price of $1365.00 I managed to get the winning bid of only $109.00. Upon arrival by courier I couldnt wait to go out the shed and "Plug and play" OOOPPPS
Not that simple Jan you need a bloody university degree to program the monster
I read the instructions more than 4 times (100 pages) Most of it I don't understand and the parts I do understand you have to program the bits I don't first
I have a mate who is an appliance tec looking at it for me now to see if he can program it up for me, But I'm affraid that if he can't do it I will be listing it on evilbay and try to recoop my money..Think I will just stick to the rpc.......I hope I havn't put you off, I just don't have muck knowledge when it comes to electrical stuff...But on the other hand I have heard some exeptionaly good things about these little buggers.....The poms love em Coz nearly all their machinery is 3phase..

I think the item is a Huanying brand.

There is a big thread on the CNCZone forum in the States (buried way down in the electronics/phase converter &VSD area).

I have just committed to purchase one for my mill.

Happy machining,
John.

Hi tanii51 & matthew_g,
A VSD can be a great way to have variable speed control on 3 Phase Motors, you need to size the Drive correctly to the Motor and the motor needs to be able to support a VSD.
Tannii51 you need to size the Drive to the 3hp (2.2kW) Motor as its the larger sized Motor. The spec's on the VSD you mentioned look ok.

Matthew, can you give me the Model Number for the AB Drive as I might be able to get you a Quick Setup document for it as I have access to AB Data and this may help you in getting your Drive running.

Regards,
Keith.

kieth in the first instance the vfd was to convert 240 v to 3 phase
the lathe motor is only 3/4 or 1 hp ( havent added that yet) but if i get the vfd to handle 3hp would i be able to use this on future motors as in 3 hp 3phase air comp or maybe a mill or does it have to match the motor more closely
hope this makes sense
john

Ok I'm confused already. The link tanii51 gave as the output as 208-240VAC. Is this per phase so 415V across phases?


Also in this link.
3HP 3 PHASE INVERTER CONVERTER LATHE MILLING DRILL SAW - eBay, Industrial Automation Control, Electrical Test Equipment, Business, Office Industrial. (end time 20-Jul-10 07:41:19 AEST)
The seller talks about changing the wiring from Star to Delta. I thought 3 phase motors stared in Star and switched to Delta(or the other way around). He also sells what he calls a dual stage inverter for motors that cant be rewired(?) 3 HP 240V to 415V 3 PHASE INVERTER CONVERTER LATHE MILL - eBay, Lathes, Metalworking Milling Welding, Business, Office Industrial. (end time 11-Jul-10 07:27:08 AEST)

I'm looking to buy a 3 phase mill but $737 + postage for the inverter makes buying a 240V one look good.

Hi tanii51,
You would need to get a 2.2kW VSD so it can be used on your 3HP Motor, it will be ok for lower HP Motors like the one for your Lathe but not larger than 3HP Motors.

Hi Stustoys,
6 Wire 3 Phase Motors are wound so they can be either wired in Star or Delta, for use with a VSD they need to be wired in Delta. The Motor Types are called Induction Motor.

Regards,
Keith.

Originally Posted by Keith_W

Hi Stustoys,
6 Wire 3 Phase Motors are wound so they can be either wired in Star or Delta, for use with a VSD they need to be wired in Delta. The Motor Types are called Induction Motor.

Regards,
Keith.

Here is a bit more detail, the smaller 415v 3phase motors can be run on 240v 3phase by rewiring from star to delta, hopefully this makes it clearer.



The VFD configuration can be a bit confusing, but most parameters can usually be left at the factory default settings, just set the motor parameters and hook up a pot to adjust the control voltage (usually 0-10v), the more advanced stuff (like torque boost and such) can be fine tuned once you have it up and running.

It's not as hard as it seems at first.

Regards
Ray

VFD's can be very useful devices. True they can take a bit of fiddling to get them to work properly but I think the results are well worth it.
I have two Siemens VFD's set up, one on my drill and one on my Lathe.
A higher rated VFD can run a lower rated motor but not vice versa. And if you are using the VFD to run a 3phase motor from a single phase supply then you need to have the correct motor.

If you are lucky your motor plate will indicate a supply voltage of 240-415V, this means that the windings can be configured to either delta (240v 3phase) or star (415v 3phase) and there will be six terminals as shown in Rays post. While some VFD's will convert single phase to 3 phase they will still only output 240V which means you need to configure your motor to delta winding.

Unfortunately a lot of machinery will have motors that only have 3 terminals and the windings are permanently configured as star as these are cheaper to manufacture. To use this type of motor you will need to break into the windings to convert it over, I sort of explained this in an earlier post (Finally Finished My 260) and while it is possible you need be a bit adventurous.

The third possibility is a 415V delta wound motor, these can not be used to run at their rated output from 240V even if it is converted to 3 phase, these types of motor are generally only very high power output types and not found on the type of machinery you would encounter in the home workshop.

Mathew, if your mate has no luck you can send me the model number of your VFD and a photo of your motors specs plate and I can probably make up a basic list of parameters to get your motor going and you can tweak it from there.

Failing all else I'll buy your VFD as I need one for the cooks wood lathe and Allen Bradley VFD's are amongst the best you can get.
Cheers,
Greg.

Great guys, I think I am getting a handle on it now. I won't worry anymore about it until I get a mill, as I'm happy enough now that I will be able to make a 3 phase mill work (with your help).
Thanks
Stuart

i think im going to raid the piggy bank soon thanmks every one for your input
john

I only have 240 V supply. I swapped the single phase motor on my Bridgeport clone mill for a 3 phase motor and VFD (bought locally). There was a lot of head scratching and re reading the manual many times but I eventually worked it out. Like everything, once you get it it seems easy. Now works great. Ramp up / slow start means the lights no longer go dim when I switch the mill on.

Check first that you can get a 3 phase motor that will fit your application. Size, mount position and size, and shaft size can all be issues. It gets a whole lot harder if these things aren't straight swaps.

Graham

Tanii51,

You should read the CNC section of this forum. A number of us use these extensivly on our machines to drive 3 phase spindles.

This is a big thread with lots of posts and information
https://www.woodworkforums.com/f170/t...d-users-96380/

/Michael

thanks michael some more reading to add to the decision which i have already made
john