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bwah
24th Jun 2015, 09:24 PM
Hi Guys,

Looking for some help selecting a VFD for a 3 phase coldsaw.
It seems to be driven by a 1.1kW single speed 3 phase motor.
I plan on powering it via a standard 20amp 240v single phase input.
Can someone please suggest a VFD capable of this achieving this task (on a budget).
I am assuming it can be a 240v single phase in 240v 3 phase out unit, given rewiring of the motor?

Here is a pic of the motor.
350899

Look forward to your responses,
THanks

NCArcher
24th Jun 2015, 09:41 PM
A 1.5kW single phase to 3 phase VFD will connect straight to that motor. You just have to re-configure the terminals on the motor to connect it in Delta.
http://www.ebay.com.au/itm/PROFESSIONAL-2HP-1-5KW-220-250V-VARIABLE-FREQUENCY-DRIVE-INVERTER/301237998597?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140106155344%26meid%3D8b4edea3219744bcbda12c6134003b27%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D271627939814&rt=nc
http://www.ebay.com.au/itm/1-5KW-2HP-single-to-3-phase-VFD-Freq-upto-400Hz-Motor-speed-vsd-vfd-/271627939814?pt=LH_DefaultDomain_15&hash=item3f3e496fe6
A quick search on eBay found these two but hunt around for a better price.

BobL
24th Jun 2015, 09:43 PM
Hi Guys,

Looking for some help selecting a VFD for a 3 phase coldsaw.
It seems to be driven by a 1.1kW single speed 3 phase motor.
I plan on powering it via a standard 20amp 240v single phase input.
Can someone please suggest a VFD capable of this achieving this task (on a budget).
I am assuming it can be a 240v single phase in 240v 3 phase out unit, given rewiring of the motor?

Correct - you will just need to switch around a few connectors inside the connection box and all should work.

VFD wise I would suggest a 2HP, 1.5kW would work on that motor quite nicely.
Does it have multiple speeds/gears?
Smaller units typically have 2 speeds 25 and 50 RPM.
If you left it in the slow gear you might not have to change the gear to get it to run at the higher speed - i.e. just run it at 100Hz?

bwah
24th Jun 2015, 09:43 PM
Thanks for the speedy reply,
there are some cheapies on ebay such as
http://www.ebay.com.au/itm/1-5KW-2HP-VFD-Inverter-7A-220V-1-Phase-Variable-Speed-Drive-VSD-Drive-Inverter-/400827425851?pt=LH_DefaultDomain_15&hash=item5d532d243b
just wasn't sure of the quality etc

bwah
24th Jun 2015, 09:45 PM
single speed switch as far as im aware
would be nice to have ability to vary speed based on material im cutting
havn't looked to far into the capabilities of vfd's yet
just want to get it running first :)

BobL
24th Jun 2015, 10:15 PM
Thanks for the speedy reply,
there are some cheapies on ebay such as
http://www.ebay.com.au/itm/1-5KW-2HP-VFD-Inverter-7A-220V-1-Phase-Variable-Speed-Drive-VSD-Drive-Inverter-/400827425851?pt=LH_DefaultDomain_15&hash=item5d532d243b
just wasn't sure of the quality etc

These look relatively new and are supposed to be vector drives,
This doesn't have much application to what you are doing but I am interested to know how good they are.

simonl
25th Jun 2015, 08:19 AM
I was reading the info on those VFd's. It states that it supports open loop vector control. I'm confused, I thought the whole purpose of vector control is to have closed loop as in a feedback circuit to monitor it's speed?

Simon

BobL
25th Jun 2015, 10:56 AM
I was reading the info on those VFd's. It states that it supports open loop vector control. I'm confused, I thought the whole purpose of vector control is to have closed loop as in a feedback circuit to monitor it's speed?
Simon

There are two type of vector control Open and Closed.

Have a read of this for the broad details
http://machinedesign.com/motorsdrives/how-choose-right-control-method-vfds

The Wikipedia page on Vector control provides a dense/technical but interesting perspective.
According to that page the Algorithm used in Vector control is based on something discovered in 1929 called the Park Transformation which has been rated the second most important power engineering publication in the 20th century.

bwah
28th Jun 2015, 02:52 PM
Can someone please confirm how the motor should be wired for 240v 3 phase output
Attached are pics of the wiring + switch front and back
Thanks


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351142351143

BobL
28th Jun 2015, 03:29 PM
Can someone please confirm how the motor should be wired for 240v 3 phase output
Attached are pics of the wiring + switch front and back
Thanks

Unless someone is familiar with that particular motor it's very difficult to just look at a junction box alike that and decide by photograph how to wire it up.
Usually the connection alternatives printed/stamped/cast on the back of the junction box lid.

I usually do all mine from first principles using an ohm meter - if R is the resistance of one coil, then a Y connected motor has a resistance between coils of 2R wheres a ∆ motor has a resistance between coils of 2/3R.

Hopefully someone will come along who has seen that particular motor before and can be more specific.

Don't just wing it, get further confirmation before connecting up

BTW the different coloured leads at the top look a bit dodgy to me - I would definitely get that checked out - Meggering the motor is also worth while.

Did you end up buying that VFD? If so did you get a manual and how easy is it to read?

bwah
28th Jun 2015, 03:50 PM
Thanks for the quick reply

I ended up getting a huanyang 1.5kW, the manual isn't the best.. but there seems to be a fair bit of info on the net about parameters etc.
Not sure what parameters apply to my application yet, being a coldsaw i think it would be quite basic?

The dif coloured leads at the top of the photo are the original 3 phase input wires
from left to right: L1, L2, L3

BobL
28th Jun 2015, 03:54 PM
Closer inspection of the photo shows the ∆ and Y symbols on the connection plate itself - see photo

The middle set of terminals looks like the common point that has conductive bridges between all 3.

Usually these metal bridges are reoriented by connection with their respective upper paired terminal and then the red wires (if they indeed the wires from the motor) are removed from the lower set of terminals and connected to the middle 3 terminals .

BUT stupidly it could also be the other way around :oo: - look under the lid of the connection box.

DO NOT RELY ON MY ADVICE ALONE - get further conformation before proceeding.
I cannot stress this enough.




http://www.woodworkforums.com/attachment.php?attachmentid=351144&stc=1

BobL
28th Jun 2015, 03:58 PM
Thanks for the quick reply

I ended up getting a huanyang 1.5kW, the manual isn't the best.. but there seems to be a fair bit of info on the net about parameters etc.
Not sure what parameters apply to my application yet, being a coldsaw i think it would be quite basic?

Yeah in the first instance I would just get it running and slowly change things to suit your need.

The think you need to be careful with those HY VFD is to never trust the factory setting - some have max frequency set to 50Hz and others have it set to 400 Hz. The frightened the shyte out of me when it first happened. So make sure the max frequency is set to 50 Hz before you press the start button.


The dif coloured leads at the top of the photo are the original 3 phase input wires
from left to right: L1, L2, L3

They look like they have been pinched between the cover and motor housing - I would look at replacing those

bwah
28th Jun 2015, 04:41 PM
how deceiving a photo can be..
i got the dslr out for closer inspection
what appeared to be a delta symbol was nothing and what appeared to be a star symbol was an X

351149

benhoskin
28th Jun 2015, 04:52 PM
That is the main switch not the motor terminals. You need to see where the wires from that switch go too. It should then have other terminals you can connect to.
You do not want to connect the vfd output to that switch.

BobL
28th Jun 2015, 06:26 PM
That is the main switch not the motor terminals. You need to see where the wires from that switch go too. It should then have other terminals you can connect to.
You do not want to connect the vfd output to that switch.

bwah, the VFD must not have a switch between it and the motor connections as the VFD must do the switching otherwise you will damage both the VFD and the motor.
While the motor is running the VFD MUST not be disconnected from the motor.

My guess is it will be something like in the following picture BUT lets get confirmation from at least one other source

forget about your blue L3, L2 and L1 labelled terminals they will no longer be able to be used because they connect to a switch underneath through to my green labelled L3, L2 and L1 labelled terminals.

The VFD has to be connected to my green L3, L2 and L1 labelled terminals.
Currently you will find metal strips between my green L3, L2 and L1 labelled terminals.
These have to be removed and placed in the orientation I have shown by the green loops in the picture.

http://www.woodworkforums.com/attachment.php?attachmentid=351160&stc=1

Let me stress again that we need more confirmation before you connect up anything.

Stustoys
28th Jun 2015, 06:42 PM
I think you're barking up the wrong tree Bob. Don't you need 6 wires to be able to change from star to delta?
I've no idea what the links are for.......... maybe for a motor that has the star point bought out to the switch terminals?

Stuart

bwah
28th Jun 2015, 06:42 PM
That is the main switch not the motor terminals. You need to see where the wires from that switch go too. It should then have other terminals you can connect to.
You do not want to connect the vfd output to that switch.

benhoskin, the red wires from the switch go into the motor housing.
there is no other terminal accessed externally on the motor.
access to red wires would require access into motor housing.

351162351163

bwah
28th Jun 2015, 06:57 PM
bwah, the VFD must not have a switch between it and the motor connections as the VFD must do the switching otherwise you will damage both the VFD and the motor.
While the motor is running the VFD MUST not be disconnected from the motor.

My guess is it will be something like in the following picture BUT lets get confirmation from at least one other source

forget about your blue L3, L2 and L1 labelled terminals they will no longer be able to be used because they connect to a switch underneath through to my green labelled L3, L2 and L1 labelled terminals.

The VFD has to be connected to my green L3, L2 and L1 labelled terminals.
Currently you will find metal strips between my green L3, L2 and L1 labelled terminals.
These have to be removed and placed in the orientation I have shown by the green loops in the picture.

http://www.woodworkforums.com/attachment.php?attachmentid=351160&stc=1

Let me stress again that we need more confirmation before you connect up anything.

hi bob,
'assuming' the input wires (cyan coloured L1,L2,L3) are connected to the switch.
if they were removed and placed to the green L1,L2,L3 terminals and the metal strips were rearranged to match a delta arrangement (pictured),
this would essentially be a 'standard' connection bypassing the switch?

351165

LexD
28th Jun 2015, 07:13 PM
The motor appears to be "Star" only despite what is written on the name plate. The switch may have NO/NC and common terminals.

RustyArc
28th Jun 2015, 07:41 PM
It appears that switch was designed to have 3 more leads going to it, the bridged terminals forming the centre of the star, in which case they could have been re-arranged to delta.

I'm wondering if that motor's been rewound and they decided not to bother bringing out the other ends of the windings?

bwah
28th Jun 2015, 08:20 PM
based on the last two posts, does this mean the motor in its current state is not suitable for 240v output?
if this is the case what would be required to enable this to occur?

thanks
Ben

Stustoys
28th Jun 2015, 08:46 PM
based on the last two posts, does this mean the motor in its current state is not suitable for 240v output?
if this is the case what would be required to enable this to occur?

thanks
Ben
Then it would appear you either have to make do with about half power or you need to get the motor wired in Delta(assuming its in star now)

Stuart

BobL
28th Jun 2015, 09:10 PM
It appears that switch was designed to have 3 more leads going to it, the bridged terminals forming the centre of the star, in which case they could have been re-arranged to delta.

Correct - forgot about that.
Ben forget everything I have written up until now.


I'm wondering if that motor's been rewound and they decided not to bother bringing out the other ends of the windings?

Looks like it.

Ben that motor cannot be converted to delta at the junction box - it needs 6 wires (not 3) coming from the motor to reconfigure between ∆ and Y.

The common point inside the windings needs to be dug out and broken into 3 separate leads. Each of these leads then needs to be brought outside the motor and connected to an appropriate one of those red wires coming from the motor.

This is not a job for the faint hearted best to take it to a motor rewinder and get then

benhoskin
28th Jun 2015, 10:26 PM
Now that we have seen the motor terminal box, you will have to do as Bob suggests,
if you want full motor hp either dig out the star point or take it to a motor rewinder to do it for you.
If you can live with 1/2 of the stated motor hp then you can wire it as is.

bwah
28th Jun 2015, 11:23 PM
thanks for everyones input, very helpful
i will investigate having it re-wired in delta
keep u posted :thyel:

bwah
2nd Jul 2015, 07:48 PM
It appears that switch was designed to have 3 more leads going to it, the bridged terminals forming the centre of the star, in which case they could have been re-arranged to delta.

I'm wondering if that motor's been rewound and they decided not to bother bringing out the other ends of the windings?

bingo! wires have now been brought out and connected in delta. see image below


bwah, the VFD must not have a switch between it and the motor connections as the VFD must do the switching otherwise you will damage both the VFD and the motor.
While the motor is running the VFD MUST not be disconnected from the motor.


If this is the case, can i leave the switch in the 'on' position and only turn the motor on via the VFD?

351471

BobL
2nd Jul 2015, 08:28 PM
bingo! wires have now been brought out and connected in delta. see image below
Great - did you do this yourself?


If this is the case, can i leave the switch in the 'on' position and only turn the motor on via the VFD?

If it was me I wouldn't risk it - if someone accidentally turns it off while it is running - not good
OR
Even if it's off but someone sees it as "on" and turns it of fand you then turn on the VFD - not good.

I would just wire the switch permanently on by moving the wires as shown
So each phase will have 3 wires attached to each other,
351472

Or At least gaffer tape cover the switch in the on position.

bwah
2nd Jul 2015, 08:56 PM
ok thanks again bob

and no i didnt bring the wires out.. i left that job for local motor rewinder

cheers

Stustoys
3rd Jul 2015, 12:40 AM
If space permits I'd think about adding a terminal block to directly connect the VSD to the windings, leaving the switch free to switch the VSD.

Stuart

bwah
3rd Jul 2015, 08:31 PM
If space permits I'd think about adding a terminal block to directly connect the VSD to the windings, leaving the switch free to switch the VSD.

Stuart

that would be nice.. not sure how to go about setting it up at this stage however

RustyArc
3rd Jul 2015, 11:30 PM
that would be nice.. not sure how to go about setting it up at this stage however

Agreed - a nice idea, but you'd have to run the 240V mains into the switch, then out again to the VFD, then run the VFD output back in to connect to the motor. In this situation, it's best left with the switch doing nothing with a separate switch or isolator before the VFD.

BobL
3rd Jul 2015, 11:53 PM
Agreed - a nice idea, but you'd have to run the 240V mains into the switch, then out again to the VFD, then run the VFD output back in to connect to the motor. In this situation, it's best left with the switch doing nothing with a separate switch or isolator before the VFD.

I don't think that was what Stu had in mind.
I think he was suggesting to just wire the unpowered FWD switch on the VFD.
This is a much better way to do it because it does not involved shutting down the VFD every time after every cut.
Usually the VFD would be left on and the FWD and STOP switch just turns the motor on/OF.

RustyArc
4th Jul 2015, 12:06 PM
I don't think that was what Stu had in mind.
I think he was suggesting to just wire the unpowered FWD switch on the VFD.
This is a much better way to do it because it does not involved shutting down the VFD every time after every cut.
Usually the VFD would be left on and the FWD and STOP switch just turns the motor on/OF.

Ah, that makes more sense. In that case you could run a light-duty shielded cable for the switching. That said, if the VFD is mounted somewhere within easy reach, you could just use the buttons on the front. If it was me, though, I'd prefer the toggle switch and ideally some kind of e-stop (which I would put on the supply side to the VFD).

bwah
4th Jul 2015, 07:00 PM
got it all wired up and running today, works a treat!

next step is to mount it in an enclosure, ideally with a toggle switch for on/off as previously mentioned..
can anyone point me in the direction of a similar thread or walkthrough for setting this up?

BobL
4th Jul 2015, 09:57 PM
got it all wired up and running today, works a treat!

next step is to mount it in an enclosure, ideally with a toggle switch for on/off as previously mentioned..
can anyone point me in the direction of a similar thread or walkthrough for setting this up?

What VFD did you end up with?

bwah
5th Jul 2015, 09:57 PM
ended up getting a huanyang 1.5kW unit
figured I would start at the bottom and if it lets me down i'll upgrade to a Hitachi NES1 unit

BobL
5th Jul 2015, 10:31 PM
ended up getting a huanyang 1.5kW unit
figured I would start at the bottom and if it lets me down i'll upgrade to a Hitachi NES1 unit


The manual should show you how to set up an external Forward/Stop switch.
From memory the switch is wired between FWD and DCM and PD001 is set to 1.

bwah
5th Jul 2015, 11:54 PM
any idea where to get enclosures/switches at a good rate?

if your interested

https://youtu.be/BvXGjjnf4Jc

BobL
6th Jul 2015, 01:41 AM
any idea where to get enclosures/switches at a good rate? ]

I only have 2 of my (9) VFDs inside enclosures.
One is for my MW lathe where the VFD is inside an old Black and Decker Orbital Sander carry case, and the other is mounted inside a galvanised tool box nut that is more of a carry case.

I either mount the VFDs direct onto the machine like these.
Sometimes you will see I have put little galvanised dust shields over the top but as I have quite good dust extraction they don't seem to do much.
This has a remote switch and speed control on the white mounting box near the main switch
http://www.woodworkforums.com/attachment.php?attachmentid=257633&stc=1

This BS uses a remote on/off switch and speed control (not visible in the picture) in a plastic box with a magnet that can be moved and attached to any part of the BS cabinet.
I could just used the VFD but there are cabinet door and foot brake interlocks involved so it's better to use remote switching.
http://www.woodworkforums.com/attachment.php?attachmentid=350239&stc=1

or I mount the VFD onto SHS posts above machines like these
Remote switch and speed control on the white box near the main switch
http://www.woodworkforums.com/attachment.php?attachmentid=251072&d=1358926169

No remote switch on this one I just used the VFD switches
http://www.woodworkforums.com/attachment.php?attachmentid=311155&stc=1

I could have done the same here - but there are also several interlocks involved so I set up a remote switch.
http://www.woodworkforums.com/attachment.php?attachmentid=351680&stc=1

Here's one where the VFD is inside the machine.
http://www.woodworkforums.com/showthread.php?t=193863

The dustier a shed is the more likely I would be to put VFDs inside enclosures.
As I said above my dust extraction is quite good - I have 2 exhaust fans and a ducted wood dust extractor system (all are more than 1000CFM).
I do have a lot of swarf and metal dust on the floor from time to time.

For remote switches I started out using small low V switches but now I like to use these
http://www.altronics.com.au/p/s1042-spst-10a-heavy-duty-toggle-switch/
because they are clearly labelled and have a very positive feel to them.
They also come with ON-OFF-ON for FWS and reverse setting in the one switch if needed.

http://images.altronics.com.au/prod/s/S1042.jpg

You will usually see an additional bright YELLOW and RED safety switch as well - This I usually use before the VFD so that it cuts the power to everything if needed.

Michael G
6th Jul 2015, 07:49 AM
any idea where to get enclosures/switches at a good rate?

I have a spare secondhand enclosure, internal dimensions roughly 200x300x130.
Where in SA are you?

Michael

bwah
6th Jul 2015, 09:04 PM
I was originally going to mount the vfd bare on a shs behind the saw but based on the amount of dust that builds up in my poorly sealed shed i doubt the vfd would last long.. i also find the on/off buttons on the huanyang to be small and tricky to press


I have a spare secondhand enclosure, internal dimensions roughly 200x300x130.
Where in SA are you?

Michael

thanks but the vfd is 180mm thick so it would not fit in that enclosure.
furthermore based on ventilation requirements and the location i want to place the enclosure it needs to be a 300w x 400h x 200d
which isn't cheap.. elec shops would charge me more than what i paid for the vfd for a enclosure that size
ebay has some for less than 100..

cheers

BobL
6th Jul 2015, 11:13 PM
I was originally going to mount the vfd bare on a shs behind the saw but based on the amount of dust that builds up in my poorly sealed shed i doubt the vfd would last long.. i also find the on/off buttons on the huanyang to be small and tricky to press
I agree the buttons are very ordinary an eventually the plastic membrane over the top of the buttons wears away as well


thanks but the vfd is 180mm thick so it would not fit in that enclosure.
furthermore based on ventilation requirements and the location i want to place the enclosure it needs to be a 300w x 400h x 200d which isn't cheap.. elec shops would charge me more than what i paid for the vfd for a enclosure that size bay has some for less than 100.

I used a very cheap ($20) galvanised tool box from bunnings for my 3p-3p 7.5HP VFD.
http://www.bunnings.com.au/rhino-465-x-282-x-193mm-galvanised-tool-box_p5810171
It's more of a transport case for this VFD and I normally operate it with the door open, but it should fit the HY OK.
If your enclosure is air tight you should fit a fan to the enclosure or at least cut/drill some air holes in the sides at the top and the bottom.
This box is so leaky it probably wont need a fan for the intermittent testing that I do with it.
If I decide to use it for extended periods with the door closed I will add a fan

The switch and speed control are on a small plastic box attached to the RHS with a magnet so it can be move to where it is needed
http://www.woodworkforums.com/attachment.php?attachmentid=351793&stc=1

Here the switch is on top of the enclosure
http://www.woodworkforums.com/attachment.php?attachmentid=351794&stc=1

The back is stiffened with some 5 mm Al plate.
The big switch on the side supplied the power to the VFD
The black rubber feet on the base and the back are pushed over wooden dowels bolted to the case.
The reason for the feet on the back is so I can lay it on its back for transport.
http://www.woodworkforums.com/attachment.php?attachmentid=351791&stc=1

The output uses a relatively unique 3P plug which reduces the chance of other plugs getting shoved in there.
http://www.woodworkforums.com/attachment.php?attachmentid=351792&stc=1