Thread: 240V 1-phase to 415V 3-phase vfd

I could have tacked this post onto my Arboga EM825 mill/drill post, but decided it's a separate topic, and reckon you would have had enough.

It seems there is available a 240V 1-phase to 415V 3-phase VFD. It is a Teco Westinghouse unit marketed by Drives Direct in the UK. At approx $430 plus postage, it's not cheap. Most VFD's are 240V to 240V or 415V to 415V, and are around half that price.

Drives Direct have an eBay store, see here 1 HP 240V to 415V 3 PHASE INVERTER CONVERTER LATHE MILL (eBay item 380286772327 end time 07-Jan-11 07:08:13 AEDST) : Business, Office Industrial

More info here Drives Direct - Digital Phase Converters - Digital Inverters 240 - 415

So, if you have a 415V 3-phase machine you wish to run at home, this is a way around the problem. I have no affiliation with Drives Direct, but wished I did. Might be able to get a discount.

Ken

Ken
Are you buying one of these? If so just remember that you cant switch the speed while the inverter is "on". Maybe some sort of flap that forces you to switch the inverter off before you can lift it to change speeds?

pm sent.
Stuart

Hi ST,

I'm trying to buy one, but can't get a response from Drives Direct re the postage cost. I have a feeling they are in the process of moving premises.

I'm spewing, they had the perfect drive on eBay at a greatly reduced price, or Buy it Now. No one bought it, and I was an hour too late to bid.

Back to your point, I would imagine that the motor would have to be stopped in any case, before changing gear ratios.

Chances are that the VFD will cover all the mechanical and electrical speeds.

If I have missed your point, please explain to this novice.

If I recall, you purchased one of these at 3HP. What are they like and physically what size is the enclosure?

Ken

I fitted a 240 to 3 phase converter to my mill. Bought locally. I can't remember the cost but can look it up if required. It has a speed control "pot" built in - its the little knob on the right under the frequency display panel in attached pic. I love it.

Graham

Hmm they used the "we are moving line" when I bought mine 5 months ago. But once you get an answer they do seem to be pretty helpful.

yeah I "saved" about 30% on mine.

I was talking about changing motor speed. There shouldnt be anything switched between the inverter and the motor while there is output on the inverter
(althought drives direct did tell me that turning the coolant pump on an off while the motor was running would be fine)

Yes you would have to have motor off to change the gears.

From 100 rpm to 2900rpm with the VSD? That would be something like 100% overspeed(on the low speed setting) and 90% underspeed. I still use the gears to get close.

They are about half the size of a shoe box. So far its been great, didnt let the smoke out when a cockroach decided to sleep inside it. I'll measure it up tomorrow if you want.

Stuart

GDD,

What was the output voltage of the VFD you purchased? I suspect it was not 415V

Stu,

Have sent you a PM with a list of questions as long as my arm.

If your answers are of interest to others, please respond here.

Ken

Ken


To late I answered you pm already. If you think others would be interested feel free to post.

Stuart

In response to some questions I sent to Stustoys, he reports:

He is very happy with his Drives Direct VFD.

Minimal programming was required.

The shipping cost from the UK to Melbourne was around 40 pounds. That's about $62 AUD

The size of the enclosure is about half the size of a shoe box. That's pretty compact.

How they derive 415V from 240V is a mystery. A trade secret I suspect.

Direct Drives state that the 3-phase motor must be star wound. To find out how my Arboga motor is wound, I will have to consult a motor expert. More dramas!

Ken

Have a look around on this site

Variable Frequency Drives - AC Tech, Hitachi, Delta, U.S Drives - wolfautomation.com

They may have something as well???..maybe

Originally Posted by Stustoys

didnt let the smoke out when a cockroach decided to sleep inside it

bugga...lol

"GDD,

What was the output voltage of the VFD you purchased? I suspect it was not 415V"

I just checked, and you're right - output is 240 volt but three phase. Pic of the motor it drives attached. I bought the motor and the drive at the same time. Motor was $282.00 and drive was $490.00 pick up down the road any time with advice and support face to face and ongoing.

The VFD has many advantages other than speed control. Most important for me is ramp up starting. The single phase motor on my mill would dim the lights every time it was switched on even though the supply wiring was all kosher. This is a worry on jobs where you are switching on and off frequently. Now when you switch on, the speed ramps up slowly. this is programmable from a fraction of a second to many seconds. No more surge loads on supply wiring.

Edit: Just re read the original post. I had missed the point about the voltage. Obviously, the motor I bought will run on either 240 volt 3 phase or 415 volt 3 phase. (you do have to re configure the connection box but this is a one minute job). Perhaps your motor is the same and will run on 240 volt 3 phase???? I know nothing about motors but have you checked this. I hope this is not a stupid and insulting question - I haven't read the other thread.
Graham

Hi neksmerj,
You should first have a look at your motor name plate to see what the windings of the motor are, either 240V Delta or 240 Star. This how you will wire the VSD, as it is Single Phase In and Three Phase 240 Out.
If you wire it wrong you will over heat your motor. From the name plate you will also get other usefull information as to Overload settings etc that you will use in setting up the VSD.
I would suggest that you mount the Drive in an Enclosure and allow a minimum of 50 to 70mm around the Drive as they like to have good airflow, in this Enclosure you can have any other Controls for you Mill/Drill e.g. Circuit Breakers Power Supplies etc.
Most Drives have a feature where you can wire in remote controls, in your case you can mount a Control Box which would have say Start Button, Stop Button, Forward/Reverse Button and a Rotary Pot for Speed Control(usually 10K).
Have a look at the local VSD Market as you could get a reasonable price for a Drive, wish you were in Sydney as I could have helped you out.

Regards,
Keith_W

If you can get away with just a phase converter why not use a cheap chinese vfd? they seem to work just fine for Spindles in the CNC Machines forum here

http://cgi.ebay.com/VARIABLE-FREQUEN...item5ada9b25f8

Or am I missing something that wouldnt make them compatible?

Ch4iS and Keith_W
As I understand it, Kens motor is 2 speed 415V only. He needs 240V single phase in, 415V 3 phase out.
There is more info on this thread
http://www.woodworkforums.com/f65/ar...resent-128204/

"You should first have a look at your motor name plate to see what the windings of the motor are, either 240V Delta or 240 Star. This how you will wire the VSD, as it is Single Phase In and Three Phase 240 Out"
I dont understand this.


Stuart

GDD,

The WEG VFD's are very good, but only if you go from 240V 1-phase to 240V 3-phase, or 415V to 415V etc, etc

Keith_W

As mentioned in my previous post Arboga EM825 mill/drill Christmas present, the nameplate voltage is stated at 415V 3-phase. I have no way of knowing if the motor is star or delta.

In my case, it's probably not going to matter. The power lead has only 3 conductors plus earth, no neutral. Therefore, 415V between phases.

Ch4iS

Oops, Stu just beat me to the punch, if you refer to my previous post, you will be right up to date.

Just found an interesting document sent to me from Phil. It shows a wiring diagram with the motor wired as delta or Y. Unfortunately, it doesn't give me a clue as how mine is wired.

I reckon this wiring diagram pertains to Arboga motors that were twin voltage, ie, 240V star wound or 415V.

Enough rambling from me.

Edit. For some reason the wiring diagram didn't attach, now it has. Pity it's in Swedish.

Ken