Another VSD Question !

[Plushy]

Hi Guys ,
Just trying to plan ahead here so i am prepared .
The Ward 3DS Lathe that i bought runs on 3 phase power so i am thinking of Wiring a VSD to it to power it and wire my motor in Delta configuration .

The Motor in the LAthe has these specs :
V 380/440
ph 3
Hz 50
rev/min 1440/940
a 8 4/9
hp 5/5
conn diag z 927698
de 345
nde 140p

So can this be wired in delta to run off the VSD ? I am guessing the motor should read V240/415 if that was possible ?

Can anyone enlighten me ?

Cheers Plushy

[Greg Q]

Is that a two speed motor? (The data has two rpm ranges)
If so, no. Even if not, it's unlikely that a 5 hp motor can be run on 240v three phase, it's probably wired 440v delta already.

How many terminals are there in the peckerhead?

(sorry, I don't know the local name for the box that contains the terminals on a motor)

Greg

[Plushy]

Hi Greg ,
thanks for the reply the motor has six wires going into the top of the motor but i cant get in there to get a photo of how they are wired . I will take a photo of the main switch box of the lathe so you can see the wiring there if it helps .

cheers Plushy

p.s are you still interested in that transformer that i posted about in the Herbert lathe thread ?

[Plushy]

here`s the wiring photos . sorry about the phone camera quality .
http://img.photobucket.com/albums/v246/Thiokol/Stuff066.jpg
http://img.photobucket.com/albums/v246/Thiokol/Stuff067.jpg
http://img.photobucket.com/albums/v246/Thiokol/Stuff068.jpg
http://img.photobucket.com/albums/v246/Thiokol/Stuff069.jpg

The six black wires that are in the middle in the last photo are the ones that connect too the motor . There is only a on/off swith at the front of the lathe as far as i can tell there is no speed switch for the motor . :)

Thanks for any help .

[Greg Q]

Hi Plushy. I can't recall the transformer right now, I'll have to search the topic to jog my memory. Was it a 415/240v by chance?

Your lathe's contactors and the six black wires kind of confirm to me that it's a two speed motor alright. Is there no "star" or "wye" symbol anywhere on the data plate for the motor?

I'm guessing that it is connected in delta already, and therefore cannot be run from a 240v VFD. Two speed motors pose another problem also in that usually only one winding can be run from the vfd.

Is your problem that you don't have three phase, or did you just want an easier speed control scheme?

Greg

[Greg Q]

Hello again. Yes I am interested in the transformer. I'm also curious if this was used with this motor?

Greg

[Plushy]

Is your problem that you don't have three phase, or did you just want an easier speed control scheme?



I Dont have three phase is the problem and cant really justify the big cost of a phase convertor to power the 5 hp motor and i am not comfortable enough with electrickery to build my own . I suppose i could buy a 5 hp single speed 240/480 3 phase motor and put that in if i wanted to run a VSD ? I will have another look to see if the motor has a delta or wye marking anywhere .

heres a photo of the motors data plate
http://img.photobucket.com/albums/v246/Thiokol/Stuff073.jpg


The transformer was offered to me in the deal with the herbert lathe apparently the transformer was to power a magnet in a scrap yard but they scrapped the idea pardon the pun

[Plushy]

I am also reluctant to fork out for aphase converter as i might be moving in the next year to a place that has three phase available .

[NCArcher]

How many terminals are there in the peckerhead?

(sorry, I don't know the local name for the box that contains the terminals on a motor)

Greg

Terminal Box will do Greg.

The starter is a Star/Delta starter it is not a two speed machine. The two speeds and currents on the name plate coincide with the different voltages that the motor will happily accept.

The motor has six wires (two per winding) directly connected to the starter. The starter then takes care of the star or delta configuration.
The star/delta starter is a reduced current starter (so you don't blow the fuses every time you start) that initially starts in star and then switches to delta once the motor is up to speed.
I think the 380/440V 3 phase are different standards from Europe. The motors were manufactured to be suitable for a number of countries. Our 415V 3 phase slots into that range very nicely.

I wouldn't think that motor was suitable for the single to three phase VSD treatment.
I'd keep an eye out for a big 1 phase motor. You may get away with less than 5 HP if the lathe is heavily geared. Hang on to the 3 phase set up in case you make the move.

[Greg Q]

I was wondering why I missed the star/delta aspect of the motor...I guess that I was expecting that to be noted on the data plate.

The advice to look for a suitable single phase motor seems like the best given the possibility of a move to three phase soon. Ebay seems to be a good source for motors.

On 5 hp vfd pricing...I expect that you'd be paying over $1000 shipped for a vfd in that power range these days given the exchange rate. The last time I was considering a 5hp VFD the only single phase input model available was from Polyspede at $600 ish U.S. That was a few months back, I think that there are other brands now available in the 5 hp size. Motors that size are not commonly found here with a star winding however, but there are some around.

If you aren't going to be using the lathe for a production load, perhaps you could get by with a 3 hp motor in the interim, keeping your 5 hp motor nice for when you shift houses.

Greg

I'll send you a pm about the transformer...

[Plushy]

The VSD i was looking at is this one from evil bay
http://cgi.ebay.com.au/3-7KW-5HP-Brand-New-single-to-three-phase-VSD_W0QQitemZ280293337278QQcmdZViewItemQQptZAU_B_I_Electrical_Test_Equipment?hash=item280293337278&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A1%7C39%3A1%7C240%3A1318

The other thing i noticed is there is a built in cutting fluid pump that is powered by the 3 phase if i swap to single phase motor i will have to disconnect this and rewire it in later ?

So what is the difference between star , delta and wye ?

If the starter has delta and star cant i disconnect the star part and use the VSD direct too the Delta wiring on the starter ?

Thanks for all your help guys i am slowly getting a understanding of this electrickery

[chrisp]

The starter is a Star/Delta starter it is not a two speed machine. The two speeds and currents on the name plate coincide with the different voltages that the motor will happily accept.

The starting arrangement may well be a star-delta starter, but the two speeds quoted on the name plate are nothing to do with the voltage. The speed of an induction motor is primarily controlled by the frequency of the supply and the poles in the motor (with some ~4% "slip" as well). The motor appears to be a 4/6 pole motor - i.e. it appears to be a two speed motor.

[chrisp]

So what is the difference between star , delta and wye ?

If the starter has delta and star cant i disconnect the star part and use the VSD direct too the Delta wiring on the starter ?

Plushy,

"star" and "wye" are the same. The three-phase winding and be connected to form a triangle (delta) or a star/wye.

If the switch gear is indeed a star-delta starter, (initially starts in "star" with 240V across a 415 winding, and then switches to run in delta with 415V across each 415V winding), the winding in the motor will be 415V windings - no good for the VFD in your link. What you really want is a 415V motor that runs in star (240V windings) and has the ends of the windings brought out so that they can be changed. Have a look at this thread for an example http://www.woodworkforums.com.au/showthread.php?t=78070

Since the motor appears to be a 4/6 pole arrangement, it may have some very interesting winding arrangements inside, so all may not be lost. If the switch gear is actually speed changing gear (rather than a starter), the motor might be a star 415V.

[Greg Q]

I remember seeing that VFD recently and was wondering about it. Is the manual for it available online somewhere? It may be an OK unit, but I am unfamiliar with the term "IGBT Space Vector". As I understand it the better drives are described as "vectorless" constant torque, and they do not require any encoder (speed sensing) feedback from the motor to provide stable speed under load.

The drive in the link is obviously Chinese made (judging by the price and the choice of fonts for the labelling). That prompts the obvious questions about documentation, reliability, accessories like remote input pads, terminals for remote potentiometers, etc.. On the other hand, the seller has good feedback and offers help, so maybe its OK.

[NCArcher]

The starting arrangement may well be a star-delta starter, but the two speeds quoted on the name plate are nothing to do with the voltage. The speed of an induction motor is primarily controlled by the frequency of the supply and the poles in the motor (with some ~4% "slip" as well). The motor appears to be a 4/6 pole motor - i.e. it appears to be a two speed motor.

I appologise Plushy, ChrisP is spot on.
It does appear to be a two speed motor. 4/6 pole. With only 6 leads coming from the motor the control gear may be a speed changer but there would need to be a switch somewhere to change between the two speeds.
On closer inspection of the photos, the bottom contactor looks like it might control the lube pump and the top two are to select the speed.
It's not a star/delta starter at all. Sorry to lead you down the wrong path. :B

[Keith_W]

Hi Plushy,
Like the others have said the AEI Motor is not suitable to be used with a VFD.
You may want to get a 5.5 kW Motor that has a Delta Windings 415V and has 6 Wires coming to the Motor Terminals.
You can then buy a VFD that has Sensor Less Vector Control, they came in 5.5 kW 24 Amps Rated Output 200-240V 1/3 Phase Input, NHP has a SINUS Micro VFD in that configeration. This way you can set it up for your single phase that you have at the moment and if you move can convert it to the three phase at the new place. VFD units like this are expensive though so you need to take this into consideration as well as the cost of the new motor and you would need to have at least 15 Amp supply going to the VFD. There also would be the need to change the control for the VFD and there could be associated cost for parts to do this as well. As for the Coolant Pump you could look at changing it to a 240V Pump.

Regards,
Keith.

[.RC.]

I suggest a 3hp single phase motor...Probably about $500 by the time you buy the necessary switch gear along with the motor...(which would be more then you paid for the lathe)

[chrisp]

You may want to get a 5.5 kW Motor that has a Delta Windings 415V and has 6 Wires coming to the Motor Terminals.

Keith,

I think you may have unintentionally made a slip. I think you may have meant to say:
"You may want to get a 5.5 kW Motor that has a Star Windings 415V and has 6 Wires coming to the Motor Terminals."
.. so that the motor can be changed to a Delta 240V configuration.

[.RC.]

A 5.5kW motor is 7.5hp, the original is only 5hp or 4kW

[Keith_W]

Hi RC & Chrisp,
Yes the kW would be 4kW.
As for the Motor I didnt say Star/Delta which I suppose I should have,as the connection would be made in Delta from the VFD.

Regards,
Keith.

[Plushy]

Thanks for all the info guys .

So i need a 415v 3 phase motor with star windings that i can change to delta 240v and a VSD that has Sensor less vector control and that should work ?

cheers Plushy

[Greg Q]

Yes, you've got it. If you want I have a brand new in box never installed 2.2 kW 240v delta three phase motor here that I want to sell. If you don't need 3.7 kw this could be a good solution for you-cheaper vfd and smaller single phase circuit required. I'm also keen to learn more about that transformer.

(Be aware that you'll need a hefty circuit for 5 hp from single phase. One manufacturer recommends a 40A circuit...I'll find a link for your information.

Greg

[Pete F]

I had a smaller star configured motor I rewired to delta and fitted with a VFD on my lathe. Despite the cries of gloom, doom, fire and brimstone that would apparently be bestowed upon me it's working just fine :rolleyes:

In my case the conversion was simply a matter of picking out the star point, to have the job done would have cost 50 bucks. The whole project was cheaper than throwing out the old motor and replacing with a single phase equivalent. Having said that, my background was "electrickery" so maybe what I take for granted may not be appropriate for everybody.

However the real beauty of running a VFD isn't so much the phase conversion, it's the features the device provides. Soft start and soft stop being 2 big ones in my book, but mostly the fact that I have never changed mechanical speeds on the lathe, just dial in the speed on the VFD. Indeed from now on, if I have an option, I will be running 3 phase/VFD on any future purchases.

The only negative in my mind is the high pitched "whine" the motor makes since it is being fed with high frequency square waves from the VFD. I'm used to it now I guess, but at first was VERY annoying. I also have to remember to turn the lathe off at the power point since the VFD is in "standby" whenever power is applied to it. Other than that I'd say if your motor isn't suitable go get another 3 phase motor and the VFD, once it's up and running you won't regret it.

[Plushy]

Thanks for the info Pete good to hear from some one else who has done thsi .

Greg i have sent you a pm with the transformer owners details , he still has it and still wants to sell it .
I will keep that 2.2 kw motor in mind . I have recieved the Ward 3DS manuals i ordered from the UK and the motor is two speed according to the manual . Ward 3DS`s came out with Single speed 6 gears setup and two speed 12 Gear setup mine is apparently 2 speed 12 gears . Is it possible to get a 2 speed motor that can be wired delta 240v 3 phase and still run off a VSD ?

cheers Plushy

i will post up the wiring diagrams here incase any one else has a WARD lathe .

[Greg Q]

.... Ward 3DS`s came out with Single speed 6 gears setup and two speed 12 Gear setup mine is apparently 2 speed 12 gears . Is it possible to get a 2 speed motor that can be wired delta 240v 3 phase and still run off a VSD ?

cheers Plushy

i will post up the wiring diagrams here incase any one else has a WARD lathe .

Hello again..

As I understand it a VFD really must be optimised for one motor (or two identical motors). The second speed is another set of windings, and it has it's own characteristics. Not to say that there might not be a VFD out there somewhere that has that capability, but it's really a parameters programming problem...easily solved with enough memory and enough connection terminals.

But, it doesn't matter because the VFD will itself give you a huge range of speeds that will exceed what was available with the factory two speed motor. Modern vector drives claim to provide full torque* down to 10% of data plate speed, and you can safely run the motor at greater than 50 Hz as well...(since most motor designs come in two, four or six pole versions with the same internals and bearings.)

*torque however is not power as we need it. Horsepower is in fact measured by torque X rpm, so although modern VFD's provide constant torque, you still do lose the power to take big chips at low rpm. I'm not sure that this is a problem in anything less than a production setting where large diameter pieces are turned and there is an obvious need for efficiency.

At least your lathe has the gearing to allow you to select a low ratio for low speed turning. Of course gearing (or belt speed reduction drives) are a power multiplier, allowing faster motor speed for a given spindle rpm.

My own lathe project has only a back gear...an a single speed pulley on the spindle. In order to replace the obsolete AC commutator motor and defunct drive I opted for a brushless AC servo motor. Otherwise I would have needed a large (5kW +) induction motor and VFD. Oh well, at least the drive was troublesome enough that the lathe has low miles even for a 1965 model and hence worth the effort to restore.

Please keep us informed of your progress with the Ward...

Best,

Greg

[Plushy]

Sorry for the Slow reply .

Here is the Wiring Diagram for a Ward Lathe with 2 speed motor :
http://img.photobucket.com/albums/v246/Thiokol/ScanLatheWiring.jpg


I have managed to find a local supplier who has given me a good deal on a Danfoss VSD that will run a 240v 3 phase delta 5hp motor and a motor to suit all for the princely sum of $1300 about 400 cheaper than anywhere else local a bit more than i wanted to pay but figured i shouldnt scrimp on the heart of the lathe . I should have them late next week then i just gotta work out what goes where with the electrickery .

The Shed has 2 phase and 100 amps available so i should be able to give the VSD and motor all the power it wants .

anyone wanna earn a slab and come wire it in ?

cheers Plushy