hello to all.

i have recently moved my workshop and no longer have 3 phase power so i wish to install a vsd to run my geared head drill, an 8 speed pollard corona.

the probem is that i don't know if it is suitable to run on a vsd as the motor is a multiple speed unit and i have heard this can be a problem

can anyone shed any light on this topic? is there anyone who has experience with vsd installation i can chat too?

if it is not possible to connect this beast, i will have to sell it.

thanks in advance. marcello

The following will be useful.
Start by posting some pics of the motor and how it is arranged in/on the drill.
Then disconnect the power and open up the junction box on the motor and let's see what is inside.

If the mechanical arrangements are not too complicated you also may wish to considered to look around for a single speed used 3Ph motor to replace the existing one. They are usually very cheap.

__________________
Check out my blog entries for forum links to most of my 2006 - 2011 projects.

I have exactly the same issue, I want to put my drill on a VFD due to it being only four speed on three phase. I will watch with interest. As for selling it no way, I can't find another drill of equivalent quality anywhere for any price this side of the national debt.

__________________
ClearVue Australia - Put the dust in the cyclone not in your lungs
http://www.ubeaut.com.au/badwood.htm
http://clearvueoz.com.au/
Chris

Hi marcello,
What Bob said + the motor rpm, hp etc or a picture of the plate if it has one.
One way or another it will be doable.

Stuart

Hi Mini,
I'm nost sure I understand, are you saying it should have 8 speeds?

Stuart

Gentlemen, can you kindly post pictures of your drills so that we can help better? Some geared drills (Arboga, Rosenfors, Strands, maybe others) have internal motors. This complicates things a bit.

There is a long thread here by Neskmerj about this exact saga on his Arboga EM825 mill drill.

If it is an internal 415v two speed motor then you have some decisions ahead about how much the machine is worth to you.

The options include:

1.A re-wind to 240v three phase, then using a 240v variable frequency drive, or VFD, to power it directly from single phase mains. This will give you a wider, infinitely selectable speed range

2. Finding a three phase transformer to step-up the voltage of a rotary phase converter...a device which will make 240v three phase. The transformer is to get it to 415v, same as your former three phase mains.

3. Finding a single coil 240v:415v transformer, stepping up 240v single phase mains current to 415, feeding a 415v VFD to get 415 variable frequency three phase power.

4. Purchasing a special VFD from the UK which converts 240v single phase mains to 415v three phase

5. There may be others answers, pending pictures/diagrams.

Greg

__________________
It's all part of the service here at The House of Pain™

Hi Marcello,

As Greg said, more information is needed. Specifically can the motor be rewired to delta. to do that you need to access the star point. Some motors have the star point buried in the windings. That would mean a trip to the motor rewinders to get the star point brought out.

Being multiple speed could mean a number of things, but most likely it's switching the number of poles. That's a problem... VFD's don't like switches between the VFD and the motor.

A picture of the motor name plate and the inside of the terminal block will help.

Regards
Ray

It is two speed switchable/two speed gear selectable = 4 speeds in all. As it is an internal motor it might be staying that way by the looks of it though I have yet to read the link above.

__________________
ClearVue Australia - Put the dust in the cyclone not in your lungs
http://www.ubeaut.com.au/badwood.htm
http://clearvueoz.com.au/
Chris

Thanks Greg, it ain't going anywhere so the decision is easy in that respect. I bought it for $150 and was offered way more than that by my Brother in law who is a well known tight ####.

__________________
ClearVue Australia - Put the dust in the cyclone not in your lungs
http://www.ubeaut.com.au/badwood.htm
http://clearvueoz.com.au/
Chris

Hi Mini,
You are currently running it on 415V 3 phase?
If so you can get 415V to 415V VSDs.
Stuart

And just to clarify fellas...when using a VFD you only need to wire it up to one set of windings. The variable speed function will let you dial it down lower than your previous lowest speed, and higher than your previous high. This allows you to extend your range AND dial up any speed you want in between.

I have done this to my 415v geared drill which has the high speed windings unserviceable. The VFD will happily run it up as high as I dare...I have decided that 2000 rpm will be my max based on a SWAG* estimate of the bearings/quill etc.

*SWAG= Scientific Wild Assed Guess

GQ

__________________
It's all part of the service here at The House of Pain™

Greg, that is the answer I needed. I was a bit puzzled on how to wire a VFD to a two speed electric motor. Thanks.

__________________
ClearVue Australia - Put the dust in the cyclone not in your lungs
http://www.ubeaut.com.au/badwood.htm
http://clearvueoz.com.au/
Chris

got to remember that one...hahahahaha

wonder if all my clients will accept it...I know a couple of them will

thanks for all of the help guys.

i will try get some photos so you can see the situation. whilst the motor is mounted on top. it forms part of the casing so i cant change that.

the controller for the motor is on a track that slides out from the back of the drill. as the drill is against a wall and weighs 400+ kg, i cant get to it just yet.

hopefully the pictures help tell the story. i will get pictures of the controller internals asap.

Attached Images

	IMG_8036.jpg (248.9 KB, 49 views)
	IMG_8037.jpg (262.6 KB, 38 views)
	IMG_8032.jpg (246.7 KB, 42 views)

Wow now that is an interesting piece of kit.
Thats a four speed motor with a two speed gearbox?
Do you really think you'll need 84rpm?(84rpm with 0.9hp? is it for boring?)


Stuart