Thread: 240v single phase to 415v 3 phase conversion

I have been reading posts on this til my eyes hurt. I am still confused.

I am simply looking into the possibilities and costs at this stage so I know what to expect if a 3 phase machine becomes available in the future.

Eg. My lathe had a 3hp 3 phase motor when I got it. I replaced the motor with a single phase 2hp motor. It needs care with the clutch to start on the 2 top speeds.

To use this as an example how would I go about converting the power supply to suit the original motor.

I have seen a number of posts saying that a lot of people on the forum are using Huanyang VFD's. These are available cheaply from EBay. When I googled "Huanyang VFD" almost the whole page was about this forum. When I did a search on "huanyang vfd" and "huanyang" on EBay I found zero results.

When searching for "VSD" I only found 240v out put up to a price I felt was outside my ability to pay.

Can anyone give me a link to a suitable unit which is priced as a number of posts have suggested. One said around $160.00. This was based on a 2.2kw unit.

Can anyone make a comment regarding the ability of a 2.2kw unit to drive a 3hp 3 phase motor on workshop machinery and what sort of power requirements would be needed to run a suitable unit. My shed only has a single circuit with (I guess) standard 16amp 2.5mm cable. It is a dedicated circuit.

Dean

Dean, this is the supplier that "most" people here on the forum have purchased their VFD from, as you can see he supplies several power ratings

love-happyshopping | eBay

This is the 2.2kw model

http://www.ebay.com.au/itm/3HP-2-2KW...item5647b1f9aa

Phase converters do not change the voltage... the 240V in units output 240V as well, not 415V...

Some motors are easily converted to run on 240V three phase... Others are not....

Hi Dean,
240V input is not a problem for most motors in the 3hp range. Many just need a simple change of wiring on a terminal block, others may need some internal rewiring, others still may require a rewind.

So really the first thing you need to know is what sort of motor you are dealing with.

Failing being able to easily change the motor for 240V input, another option is to run a 415V motor on 240V and make do with 50-60%hp.

Then there is the costly path of 240V input 415V output(I have one of them). I'd really only suggest that as your last option before a motor rewind.

This is the guy I bought my four from(because he was the cheapest at the time, he may not be atm)

http://www.ebay.com.au/itm/300533234...fvi%3D1&_rdc=1

Worked out at $125 each delivered.

There are other ways to go about it, e.g. a 240v to 415V transformer into a 415V VSD, but again I wouldnt do any of those unless I didnt have a choice.

Stuart

I just converted mine with Huanyang 1.5kw recently, Thanks to RayG

Original Star configuration with 415V


I changed to delta 240V


I bought this band to extend the control panel


and the terminal


here its







here is the main unit

Originally Posted by Stustoys

Hi Dean,
240V input is not a problem for most motors in the 3hp range. Many just need a simple change of wiring on a terminal block, others may need some internal rewiring, others still may require a rewind.

So really the first thing you need to know is what sort of motor you are dealing with.

Failing being able to easily change the motor for 240V input, another option is to run a 415V motor on 240V and make do with 50-60%hp.

Then there is the costly path of 240V input 415V output(I have one of them). I'd really only suggest that as your last option before a motor rewind.

This is the guy I bought my four from(because he was the cheapest at the time, he may not be atm)

VARIABLE FREQUENCY DRIVE INVERTER VFD NEW 3HP 2.2KW 10A | eBay

Worked out at $125 each delivered.

There are other ways to go about it, e.g. a 240v to 415V transformer into a 415V VSD, but again I wouldnt do any of those unless I didnt have a choice.

Stuart

Hi Stuart,

I need a quick lesson on 3 phase. I always thought that 3 phase was still only 240 volts relative to ground and that the 415 volts was achieved across any 2 phases due to the phase angle?

Which leads to my next question. whats the difference between 240V 3 ph and 415V 3 ph?

Cheers,

Simon

Hi jackaroo,
Where did you get the cable and plug and what are they called?
Thanks

Hi Simon,
Rapidly heading out of my depth.

Originally Posted by simonl

I always thought that 3 phase was still only 240 volts relative to ground and that the 415 volts was achieved across any 2 phases due to the phase angle?

Our 3 phase is(or at least most of it?), other counties aren't.

Originally Posted by simonl

Which leads to my next question. whats the difference between 240V 3 ph and 415V 3 ph?

The voltage?
I'm not really sure what you are asking here. "why are some motors dual voltage?" maybe?

Stuart

OK. I'm assuming there is a difference between 240V 3 ph and 415V 3 ph.

In order for me to get my head around it (humour me here) can you help me conduct a theoretical experiment? If we had 240V 3ph outlet and we measured the voltage difference between 2 phases what would/should we see? Now we measure the voltage difference between one of the phases and ground, what would we see?

Now, lets do the same measurements for 415V 3 ph. What would we see?

Cheers,

Simon

Originally Posted by simonl

OK. I'm assuming there is a difference between 240V 3 ph and 415V 3 ph.

In order for me to get my head around it (humour me here) can you help me conduct a theoretical experiment? If we had 240V 3ph outlet and we measured the voltage difference between 2 phases what would/should we see? Now we measure the voltage difference between one of the phases and ground, what would we see?

Now, lets do the same measurements for 415V 3 ph. What would we see?

Cheers,

Simon

With a 240v 3 phase system voltage phase to phase is 240v
If it was configured as a 4 wire system (ie with neutral) ,voltage from phase to N would be 240/Sqrt3 or about 138V

For 415v 3 Phase, phase to phase voltage is 415. Phase to neutral or ground is 240V

Hi Stuart, I bought them from Altronics,
the band/ribbon
Altronics - Your One Stop Audio Visual & Electronics Supplier

the connector is this one but they got the wrong picture.
Altronics - Your One Stop Audio Visual & Electronics Supplier

Trong

Hi Trong,
You wouldnt happen to know which pot these use for speed control?
I'm guessing this one
Altronics - Your One Stop Audio Visual & Electronics Supplier
Though maybe the shorter one would do?

Stuart

Stuart, RayG did a thread about the external front panel and the pot, from memory it was a special pot that he got from os

http://www.woodworkforums.com/f65/hu...el-pot-147356/

this is how iv been told they work very simplistic but ( i have 2 one huanyang and a seimenS
they use devices called igfets which are high speed high current switching devices
basically they switch the 240 volts to each leg of motor winding ( 3 windings )
the speed is adjusted by how fast the 240 v is applied to each winding
standard is 50 hz in australia so if its applied slower say 20 hz the motor will go slower if its raised to 75 hz it will go faster all controlled by a simple potentiometer.
Motor can be reversed by simple switch making the pulses of 240v applied to the windings in reverse
vfds are capable of many other things such is how fast the motor speeds up to full speed and also slowing down to stop all adjustable to the parameters you want
extra outputs to power relays and controls also
just a few things they can do
my 1400 rpm motor is set to go from 100rpm to 2200rpm and braking to stop in 2 seconds
with forward and reverse
The hardest thing i found was setting all the parameters as there are virtually hundreds of different combinations they have in built current overload protection which you can set at whatever you like up to the maximum the vfd is rated at
some of the more exotic vfds can even compensate for the motor slowing down under load ( called vector invertors)
please feel free to correct me on any miss information as im only a self learner
JOHN

can you put a stop/forward/reverse switch between a VSD and the motor, say like a drill press so you can tap with it?


Thanks
Jake.

Originally Posted by AUSSIE TD-40

can you put a stop/forward/reverse switch between a VSD and the motor, say like a drill press so you can tap with it?

Hi Jake,
No
But you could do the forward/stop/reverse with the VSD.

Hi Big Shed,
Thanks. I remembered the post but didnt think I had a chance of finding it(tI thought it was in another thread, not that we do that sort of thing around here ). It confirms(I'm pretty sure) that I've picked the correct ones, I need something to pad the order up to $20 altronics min)

Stuart