VFD for 3 Phase Mini 30

[gorriss]

Hi
This is my first post, so hi to everyone. I just bought a SCM L'Invincible Mini 30 combination machine. It is 3 phase 760/440 volt and I only have single phase power. My intention was either : Get 3 phase on at home (too expensive), Get a rotary converter (noisy & inconvenient), put in single phase motors. The last option was my preference but the spindle moulder is 2 speed and it seems 2 speed single phase motors are not available. So my current idea is put in new 240V 3 phase motors and use a VFD to get the speed options on the spindle moulder. It seems a VFD is usually connected to just one motor although from my many phone conversations it seems I may be able to do what I want. Apparently I would need some kind of isolation switch to do that. I could put single phase motor for one and just use VFD on spindle moulder motor but that seems a tad messy (plus 3 phase motors are cheaper).

Can anyone tell me some general info about how a VFD is wired up. Apparently the VFD will not be mounted on the machine. I am unclear if I can use the existing stop start controls on the machine, or have to operate everything from the VFD. I was told DON'T SWITCH LOAD SIDE OF VFD or I will blow it up. Not 100% sure what that means (I guess don't switch machines on/off while VFD powering them?) Just after some ideas about the best/cheapest way to set this up.

[RayG]

Hi Gorris,

First up... welcome to the Forum!

You already have it pretty much correct, the VFD's function is primarily to provide a 3 phase output, you get the speed control as an added side benefit.

First, the single phase incoming mains is rectified to produce straight DC, which then drives IGBT's to produce a 3 phase output, the reason for not wanting switching between the motor and the VFD is to avoid sudden load changes that could damage the VFD, at least that's the theory..

Second, since the existing machine controls are no longer doing anything, the usual practice is to rewire the start/stop/e-stop switches to control the vfd.. in the case of the e-stop it's normal to have a latching contactor upstream of the vfd, and the e-stop unlatches the contactor dropping power.

Hope that clarifies some of your questions.

Regards
Ray

[BobL]

Ray has given you some good info.


. . . I was told DON'T SWITCH LOAD SIDE OF VFD or I will blow it up. Not 100% sure what that means (I guess don't switch machines on/off while VFD powering them?) Just after some ideas about the best/cheapest way to set this up.

When using a VSD the standard power switch on a machine is usually deactivated and the VSD unit (which has switches on it) is used as the motor switch and speed control. If the power to the VSD is turned off the machine reverts to a safe state so there's no problem with the machine starting to move when the power to the VSD is restored.

For a multi motor machine a single VSD can be used but what you would need is a switch (or set of interlocked switches) which switches off the power to the VSD before the VSD output could be switched to a different machine.

There's probably already some kind of switch out there but one way to do this would be to wire a 24V retic solenoid power supply into the same circuit as the VSD power. ie if VSD is powered the solenoid is active and it latches shut a small door behind which is the switch to disconnect/connect the VSD to different machines. To access the "switch the machines switch" you would have to turn off the VSD power. I kind of like that - could be worth having a crack at doing this.

One downside of using a single VSD to power multiple machines is that you would have to learn how to program and run different programs to provide the machines with different operating parameters ie different frequency/spped ranges etc.

[Stustoys]

760/440V? Whats that?

I run two machines off one VSD with a 4PDT center off switch. The fouth pole is a control wire that doesnt allow the machine to be "on" when the vsd is switched to it.
If I switch the vsd from one machine to the other while one is working I guess it would depend which contact opened first as to what would happen, but on my head be it.(the vsd is on coasting stop so I guess it could be switched from one machine to the other as soon as the stop button is pressed)

Given what these machines seem to go for and guessing that there are only two motors. If the motors will run on 240V I think I'd be going with 2 VSDs.

Stuart

[gorriss]

Thanks for your replies. I thought I would get email notification of any posts but I didn't, hence my late reply. I have got my head around the way VFDs work a bit better now. I am planning on still having one VFD for the 2 motors, since they are identical and normally run at the same speed. Mainly I only want to vary the speed on the spindle moulder motor. Anyway, correct me if this is wrong, but this is how I plan to do it. Basically I will disable all the controls on the machine itself. I will put a 2 way selector switch on the machine itself, which will be connected directly to the VFD and then to the two motors. So the switch is always directly connecting one and only one motor to the VFD. Obviously you would never touch this switch while the machine was running (why would you want to anyway?). I will be happy to switch the machine on and off directly from the VFD so I don't believe I need to wire anything else?

Is this doable, or have I got it wrong.

Cheers
Graham

[gorriss]

Actually I just re-read your posts. So the VFD ITSELF has to be powered off before changing the selector switch? Does that mean even if the machine is not running? I would have thought the VFD could be powered on but as long as I don't have it driving anything I could switch the load?

[BobL]

Actually I just re-read your posts. So the VFD ITSELF has to be powered off before changing the selector switch?
That's what the manuals say

Does that mean even if the machine is not running?
Correct

I would have thought the VFD could be powered on but as long as I don't have it driving anything I could switch the load?
Nope - the manual says VFD MUST be off.

[gorriss]

Thanks Bob. My other option is to put a single phase motor in for the fixed speed functions, and just use the 3 phase plus VFD for the spindle moulder. The extra cost of single phase motor is much less than another VFD.

Graham

[Stustoys]

Just to disagree with Bob.
My understanding is only the output of the VSD must be off for switching.

(from memory) My manuals say "no swtiching" and leaves it at that. Which manual are you talking about Bob?


Cost would depend on what VSD you plan on using. You can get 3hp ones off ebay for around $140. Though they are 240Vinput/output. I still dont understand your 760/440 volt comment? If the motors cant be rewired for 240V your options become more limited.

Stuart

[gorriss]

Hi Stuart

The 760/440 motors are the originals in the machine. I can't use them unless I get 3 phase on at my house, so I plan to replace them with 240V 3 phase motors and VSD. The VSDs I have been quoted on are $550 - $650 (The cheaper was a Teco). Can you give a link to the $140 ones? Are they OK?

Graham

[BobL]

Just to disagree with Bob.
My understanding is only the output of the VSD must be off for switching.
(from memory) My manuals say "no swtiching" and leaves it at that. Which manual are you talking about Bob?

You are correct - The Huanyang VSD manual says this

Do not install any switch component like air circuit breaker or contactor at the output of the inverter. If any of such components must be installed because of the requirements of process and others, it must be ensured that the inverter has no output when the switch acts.

My SAJ VSD manual effectively says the the same thing but in a version of Chinlese that led me to believe the VSD had to to be turned off.

[gorriss]

Thanks for the clarification. It sounds like my plan will work then. On a slightly different note. The current spindle moulder motor has a 100L frame (bigger than the 90L models I want to buy). It only has a bigger frame because it is a 4 pole dual speed motor. The problem is the 100L has a 28mm shaft and the 90L has a 24mm shaft. My existing motor has a 150mm x 45mm belt pulley. Can I use a sleeve to mount this pulley on the smaller shaft or do I need a new pulley? If so, any ideas where or how much? I am in WA.

Cheers
Graham

[Stustoys]

Hi Graham,

Thats what I thought you meant..........who uses 760 3 phase?(or are they what I would call star start delta run motors?)

You dont say what hp you need.
this is the first 3hp cheapy I found
PROFESSIONAL 2.2KW 10A 220-250V 3HP VARIABLE FREQUENCY DRIVE INVERTER VFD t7 | eBay (http://www.ebay.com.au/itm/180828475524)

Of course if you get two you'll likely be able to get them a little cheaper. I bought 4 for $125 each delivered but that was over a year ago now. There are many sellers. They are all still working but most dont get much use. Many others on the forum have them, I am only aware of one that has gone up in smoke.

Just to had to the confusion. At your price of $550-$650 what may work for you is a Teco from the UK that has been modified for 240V single phase input - 415V 3 phase output. I have one. Its the one I switch the output on in fact. Working fine so far, I doubt I would go this route again but it could be an option for you.


Stuart

[gorriss]

Hi Stuart

I didn't think you could get a VFD that did 240V single phase to 415 3 phase? That would be a great option because obviously I can keep my existing motors - cheaper all around and less work. So it works OK for you. What sort of motors do you have? I have heard that VFDs can damage older motors. Apparently you should preferably use inverter rated motors? My motors are probably around 1980 vintage.

Graham

[gorriss]

PS Both motors are 3hp aprox 2800 RPM.

[gorriss]

Just to had to the confusion. At your price of $550-$650 what may work for you is a Teco from the UK that has been modified for 240V single phase input - 415V 3 phase output. I have one. Its the one I switch the output on in fact. Working fine so far, I doubt I would go this route again but it could be an option for you.
Stuart

Any chance of a link to that VFD? Can't seem to find it. I did see one here Drives Direct - Digital Phase Converters - Digital Inverters 240 - 415 (http://www.drivesdirect.co.uk/Products/Digital_Inverters240_415.htm) for UK425 (pounds)

Graham

[Stustoys]

Hi Bob,
Thanks for that, shows how good my memory is......I thought it just said "dont do it"

Hi Graham,

3 HP DIGITAL 240V to 415V 3 PHASE INVERTER CONVERTER FOR BRIDGEPORT MILL LATHE | eBay (http://www.ebay.co.uk/itm/150996343780)

Now traditionally it has been hard to get reply to an email from him.*
He also seems to not understand that we dont have to pay VAT.
Maybe things have improved?

I've also read about the old motors and vsds but am yet to have an issue. I run three old motors, one I dont know the age of runs on 240V delta, two are likely 1960's if not before, one of those is runs on 415V in star(on the 415V teco) the other I havent rewired so runs wired for 415V star on a 240V VSD. I dont tend to run those machines at anything other than 50Hz unless I am testing settings for someone and then wont go above 60hz but will play around below 50. I'm yet to have an issue but you never know.

And there is yet another option. You could run your motors on a 240V vsd and put up with the power lose(call it 1/2). Though as you want to be able to run the motor at 25hz I doubt thats a good idea as you'd likely have something around .75hp(if that).

Stuart

p.s. Thats the guy Graham, I type slow ;)

*I've just been back through my emails and he isnt as bad as I remember except for one which 3 weeks to get a reply, the other 5 where answered the same or following day. Though I recall neksmerj who also has one had issues with him also.
I've had mine since 5/8/10 though it likely only has a couple of 100 hours on it.

[BobL]

Hi Stuart

I didn't think you could get a VFD that did 240V single phase to 415 3 phase? That would be a great option because obviously I can keep my existing motors - cheaper all around and less work.
.
.
.
I have heard that VFDs can damage older motors. Apparently you should preferably use inverter rated motors? My motors are probably around 1980 vintage.


I am running a circa early 1960s 1/2 HP Macpherson 3-Phase 415V motor on a 1.5 kW "240V single-phase to 240 3-Phase" VSD and it has worked fine for the last two years but the motor lacks guts because the 240 V 3-phase output of the VSD when applied to the motor does not generate as much torque as when driven by 415V. I will soon be upgrading that motor to a 1 HP "240v 3 Phase" OR "415V 3 Phase motor" that should have more than enough grunt.

[Stustoys]

I am running a circa early 1960s 1/2 HP Macpherson 3-Phase 415V
Why? not game to dig the star point out of 50 year old windings?
Thats why my Hercus drill is running in 415 :D.

If it ever worried me I could move the Hercus onto the 415V VSD and the shaper to the VSD off the hercus as the shaper motor has the star point bought out. Not as much of as issue for me I guess as the Hercus motor is at least 2hp so I still have 1hp.

Stuart

[BobL]

Why? not game to dig the star point out of 50 year old windings?
Yeah - did that on another old Macpherson and twas a right PITA.

Just before I installed the VSD on the Hercus I was promised a 240/415V delta/star motor so I wired the Hercus up "as is" till I got the new motor. After more than 12 months of promises the promise fell through and I started a search for another motor - anyway 21 months later I now have 2 of them so I can finally switch the Hercus back to full grunt+.

[gorriss]

3 HP DIGITAL 240V to 415V 3 PHASE INVERTER CONVERTER FOR BRIDGEPORT MILL LATHE | eBay (http://www.ebay.co.uk/itm/150996343780)

I've also read about the old motors and vsds but am yet to have an issue. I run three old motors, one I dont know the age of runs on 240V delta, two are likely 1960's if not before, one of those is runs on 415V in star(on the 415V teco) the other I havent rewired so runs wired for 415V star on a 240V VSD. I dont tend to run those machines at anything other than 50Hz unless I am testing settings for someone and then wont go above 60hz but will play around below 50. I'm yet to have an issue but you never know.


I emailed a guy at Teco in Perth about this device and he replied and said 240V in 240V out no question. I think this device must be a static inverter with a VSD as well, sinec apparently a VSD can't up the voltage. I looked at a static inverter for sale near me (Polyphaz .55/4) already. I rang Polyphaz and they said I need a rotary converter and the static inverter would probably not start my machine. Is any one using the Drives Direct Inverter (see link above) for 3hp motors as I want to do?

Graham

[Big Shed]

Graham, this forum member has imported one from Direct Drives, I'm not altogether sure whether he has actually got it wired up and working.

If you start reading here:

http://www.woodworkforums.com/f65/240v-1-phase-415v-3-phase-vfd-128758/

He also has several other threads on this subject, so a search would find those if you want further details.

[Stustoys]

Is any one using the Drives Direct Inverter (see link above) for 3hp motors as I want to do?
Yes. Me.


Just to had to the confusion. At your price of $550-$650 what may work for you is a Teco from the UK that has been modified for 240V single phase input - 415V 3 phase output. I have one. Its the one I switch the output on in fact. Working fine so far, I doubt I would go this route again but it could be an option for you.


The Teco guy is correct, Teco doesnt sell a VSD that "ups the voltage". It is a modifaction done by the guy in the UK. As I understand it the modifaction uses a 415V-415V Teco VSD with a voltage double added to the front end. But I really dont know.

Stuart

[Stustoys]

This might give you some ideas.
http://www.woodworkforums.com/f65/vsd-enclosure-129337/ (http://www.woodworkforums.com/f65/vsd-enclosure-129337/)

I should add it depends a little on what you intend to use this machine for.
If you are going to earn a living with it I would think about trying it on 240V*. Then switching one or both motors out as needed. As Drives Direct is the only guy I know of modding these, that could be an issue if it drops dead. If its just for a hobby then that wouldnt be the end of the earth.

Stuart


*which as I said earlier likely wouldnt work for you, but it depends

[gorriss]

Thanks again all for your help. I want the full grunt of at least 3hp, so I don't think running 415V motors on 240V will work for me. I have emailed the guy in UK about his VFD. If it does the job it is definitely my best option as I also have a pulley that wont fit the 90L motor so that's more complication (although I am investigating a 100L frame 3Kw motor that may still work with a 2.2Kw VFD? That will be more $ too!).

I was just a little cautious about your application (Stuart) because I think you are using a smaller motor, but I could be wrong?

Graham

[Stustoys]

I want the full grunt of at least 3hp
ok so the cheapest easiest option is out then.


although I am investigating a 100L frame 3Kw motor that may still work with a 2.2Kw VFD?
If you bought a new 3kW 240V motor you can get cheap 3kW 240V vsd's.
Though you start to run into problems with suppling the current required. Will the machine take it?
I think running a 3kW motor on 2.2kW vsd is doable but I'm not 100% on that.


I was just a little cautious about your application (Stuart) because I think you are using a smaller motor, but I could be wrong?
Both the motors I currently run on the 415V VSD are 3hp.

Hope I'm being more helpful than adding to the confussion.

Stuart

[gorriss]

Thanks Stuart I think that really answers my question. You are successfully running 3hp (at least one old one too) motors on the 415V VFD much like I want to do. Hopefully I will hear from Drives Direct soon. It is really quite an economical and simple solution for me. I guess I could actually still use the 2 speeds of the 4 pole motor to vary speeds even though I can do it with the VFD. The only downside is more switching on the machine which just means more care to make sure they are switched correctly when I turn on the VFD.

I just had a look at your original post showing your setup. I am hoping mine can effectively be much simpler. Please tell me if I have this wrong but I plan that:
1. The VFD will be hard wired to its own 15 Amp circuit with its own breaker to turn the VFD on/off.
2. One 5 core cable will be used to send 415V three phase from the VFD to my machine.
3. I will (effectively) have a selector switch on the machine which allows a direct connection between VFD and one motor only at any time.
4. All powering on/off and speed variation of the machine will be done from the VFD itself (no need of remote switching etc)

Graham

[Stustoys]

I guess I could actually still use the 2 speeds of the 4 pole motor to vary speeds even though I can do it with the VFD.
Something I havent tried but if I was doing what you are doing I would certainly leave it as an option until I was happy with the motor power at 25Hz.(or 100hz if you wire it for low speed)


The only downside is more switching on the machine which just means more care to make sure they are switched correctly when I turn on the VFD.
Yes, If you thought it nessary you could fit a door over the controls on the machince along the lines big shed(?) was talking about in an earlier post.



I just had a look at your original post showing your setup. I am hoping mine can effectively be much simpler.
Mine only looks complicated as I've run the controls to the machine. Yours shouldnt need to look anything near that bad ;)

I perfer to use the factory controls were possible, others bin the controls and start over.



1. The VFD will be hard wired to its own 15 Amp circuit with its own breaker to turn the VFD on/off.

As long as the breaker isnt to far away. (I'd prefer a switch close by the VSD, but thats your call)


2. One 5 core cable will be used to send 415V three phase from the VFD to my machine.

Why 5 core? (unless you have it already)



3. I will (effectively) have a selector switch on the machine which allows a direct connection between VFD and one motor only at any time.

yes
I assume you currently have an ON/OFF switch for one motor and a 1/off/2 switch for the two speed motor. Anything else?



4. All powering on/off and speed variation of the machine will be done from the VFD itself (no need of remote switching etc)

Depends where the VSD is going to be mounted. I would want at least a stop button some where as the control buttons are a little on the small side if you were in a hurry.
Also while you can control speed with the keyboard I think you will find a pot much easier. I've only even used an external speed pot. I dont think its as easy to fit an internal speed pot to the Teco as it is on other drives. Unless you just want fixed speeds and you can do that with switches.

Stuart

[gorriss]

Why 5 core? (unless you have it already)Stuart
The machine has a 5 core cable for 3 phases, 1 neutral, 1 earth. I thought that was normal?



I assume you currently have an ON/OFF switch for one motor and a 1/off/2 switch for the two speed motor. Anything else?Stuart
My machine has ON/OFF for one motor and 1/OFF/2 for the other as you say. It also has 2 big switch boxes on the other side (1 for each motor) that has 3 buttons for ON, OFF, RESET.



Depends where the VSD is going to be mounted. I would want at least a stop button some where as the control buttons are a little on the small side if you were in a hurry.Stuart
Yes a stop button sounds like a good idea even though machine does not currently have emergency stop button.



Also while you can control speed with the keyboard I think you will find a pot much easier. I've only even used an external speed pot. I dont think its as easy to fit an internal speed pot to the Teco as it is on other drives. Unless you just want fixed speeds and you can do that with switches.Stuart
OK maybe I will do a speed pot too.

So is it OK to have a flex type cable just sitting on the floor between VFD and machine? I guess it is effectively the same as an extension cord to any other machine. Don't want to trip over stuff, but it's the only option I spose.



Graham

[Stustoys]

The machine has a 5 core cable for 3 phases, 1 neutral, 1 earth. I thought that was normal?
You wont have any use for the neutral.
Its there so you can get the single phase voltage from one of the 3 phases. But you cant do that with a VSD. Though if thats the wire you have it will be fine.



My machine has ON/OFF for one motor and 1/OFF/2 for the other as you say. It also has 2 big switch boxes on the other side (1 for each motor) that has 3 buttons for ON, OFF, RESET.
The 2 big switch boxes will need to be removed or at least the internals bypassed.


So is it OK to have a flex type cable just sitting on the floor between VFD and machine? I guess it is effectively the same as an extension cord to any other machine. Don't want to trip over stuff, but it's the only option I spose.
Yes, though there is a limit on the length of cable you can have but I cant recall what it is ATM.
Could you drop the power from the roof/ceiling?

Stuart

[BobL]

. . .Yes, though there is a limit on the length of cable you can have but I cant recall what it is ATM.


In the two manuals I have they say 15 m for the 240V 3-phase and 30 m for the higher 3 phase voltages.

[jhovel]

Not trying to confuse any more issues here....
The cable from the VFD to the motor(s) gives off a lot of electromagnetic field 'noise'. If you intend using and electronic gear near the machine (such as digital verniers, digital readouts etc), then you really need to run that cable in metal conduit - the flexible kind if you like - and ground it at the motor end (although I don't understand why that end).
Many people find it easier or more convenient to mount the VFD on the machine with a very short shielded cable between it and the motor(s). That way the cable draping to the machine is only single phase (cheaper) and you can read the VFD display at closer range or change settings easier directly on the VFD.

On the other hand, the VFD should be installed in a dust protecting housing of some sort to keep it's fan cooled innards clean and efficiently cooled....

Your call.

[gorriss]

Well I just rang Dave at Drives Direct. I gathered all my motor specs before I called and realized the spindle moulder motor is actually 3.1HP (2.5Kw). Dave said I would need the 5HP model which is his next size up. Unfortunately that one is UK775 which is still $927 after the 20% VAT is taken off. That's a bit over budget plus $75 freight, so $1000 all up. I think I would prefer the 240V motors and VFD for a similar price. My only problem is the pulley on the 100L motor (28mm shaft) needing to go on a 90L frame with 24mm shaft. I think I already said it is a 150mm diameter by 45 wide crowned belt pulley. Must be able to get one somewhere at a reasonable price I would think.
Graham

[BobL]

On the other hand, the VFD should be installed in a dust protecting housing of some sort to keep it's fan cooled innards clean and efficiently cooled....


Another approach to this is to serious beef up your dust extraction.

On my wood working lathe the VSD is mounted on a steel post about 500 mm above the lathe centre line.
http://www.woodworkforums.com/attachments/f245/218560d1344257928-bobls-shed-fit-wwlathedc1.jpg

Like the one on my metal work lathe I thought about putting the VSD inside a housing to protect it from dust in the end I settled for a small sheet metal roof over it to reduce the exposure to settling dust and knocks from on top. I also have 1250 cfm of air flow / dust extraction within 200 mm of the lathe centre line which is very efficient at grabbing the fine dust at source. I know this because when I measure invisible dust levels using a particle counter located right next to the VFD I only see the same levels of dust as there is present in outside shed air. Yes there is a shyte load of visible shavings on the bench and floor but the fine dust is rapidly sucked away by the 1250 cfm.

[Stustoys]

Hi Graham
Did you tell him it was 3.1hp at 440V?

Joe brings up a good point.
While I dont take much care of my cheap VSD's I do try and keep my Teco cleaner. As I am 98% steel its not nearly as much of an issue.

Big Shed, I've been meaning to add something like that over a couple of my VSD's

Stuart

[gorriss]

Hi Graham
Did you tell him it was 3.1hp at 440V?
Stuart

I am pretty sure he would have understood that.
The VFDs I have been quoted on by motor suppliers (WEG & TECO) were $550-650 as i think I already mentioned. The WEG guys said if I didn't get the WEG VFD my motors wouldn't be covered by warranty. Been looking at a Chinese No Name Brand VFD on EBay for $265 and you have pointed me to others overseas for under $100. Are these cheaper ones a problem, and should I worry about warranty? As for motors, the Teco won't fit because the junction box is too big. The WEGs look good but $330 each (3hp 240V 3 phase). Are Baldor a good motor? Anyone got recommendations for good motors or VFDs?
Graham

[Bob Willson]

The WEG guys said if I didn't get the WEG VFD my motors wouldn't be covered by warranty.

I am almost certain that he is not telling the truth here. The motors are a complete unit in and of themselves, so it should not matter what they are driven by.
This sounds a little like Telstra not taking responsibility for their phone lines unless you use one of their telephones. I would definitely check this out with the ACCC.

[BobL]

I am almost certain that he is not telling the truth here. The motors are a complete unit in and of themselves, so it should not matter what they are driven by.

I'd ask to see this in writing on the warranty.

[gorriss]

When I mentioned the VFD I was looking at from Shanghai Shanyu Electronics Equipment Co Ltd (link below)
2.2KW ,3HP single to 3 phase 0-600Hz Variable Speed Drive VSD VFD Motor control | eBay (http://www.ebay.com.au/itm/2-2KW-3HP-single-to-3-phase-0-600Hz-Variable-Speed-Drive-VSD-VFD-Motor-control-/281067324673?pt=AU_B_I_Electrical_Test_Equipment&hash=item4170eb0501)
they just said "never heard of it" which is understandable I guess. Obviously not all VFDs are alike and some presumably could be more likely to damage a motor than others. I guess that's why people buy reputable brands. But on the other hand, reputable brands often jack up their prices because of the brand attached. It can be hard to know!
Graham

[Stustoys]

I am pretty sure he would have understood that.

Maybe not.
Bearing in mind I am rapidly heading out of my depth.
As I understand it, "as far as the VSD is concerned" 3.1hp at 440V is 2.2kW at 415V. Running a higher Voltage higher Hp motor on a lower Voltage VSD with a lower hp rating has been discussed here in the past though I'm not award of anyone that has tired it. Though we were discussing things more along the lines of a 5kW 415V motor on a 2.2kW 240V VSD.
With a $125 VSD I'd say "give it a go". Not so sure about the $600 Teco though(without comment from someone that knows more about these things).
Also the cheaper VSDs display output current(and voltage?) so you can keep an eye on whats going on . The Teco doesnt.
In the end its your money.

I see others have covered the WEG guys.
What does WEG say about using 1 VSD on two motors?

"under $100"? under $200??

I'm not aware of anyone that has damaged a motor using a VSD(not saying it hasnt happened and my memory sucks at the best of times). I would be more worried if you were going to try run the motor at 50 and 100Hz* rather than 25 and 50Hz, but I cant really comment as I have almost never gone over 60Hz and when I have it wasnt under load(though I dont know if that matters). also while we are on the subject, if you are going to run at 25Hz watch your motor cooling.

What a wishy washy post.

Stuart

*I think Joe tested from normal 50Hz motors at higher Hz and they were running out of puff just over 100Hz if I recall correctly.

[gorriss]

Thanks Stuart
I will give Dave another ring tonight regarding the 3.1hp @ 440V. $615 inc freight for the 3hp 240-415 model and no pulley problem to worry about (plus got my 2 speed motor still!)
Cheers
Graham

[BobL]

I'm not aware of anyone that has damaged a motor using a VSD(not saying it hasnt happened and my memory sucks at the best of times). I would be more worried if you were going to try run the motor at 50 and 100Hz* rather than 25 and 50Hz, but I cant really comment as I have almost never gone over 60Hz and when I have it wasnt under load(though I dont know if that matters). also while we are on the subject, if you are going to run at 25Hz watch your motor cooling.

My Hercus 9" has 1/2HP 415V 1440 RPM running on 1.5kW 240 V SAJ VSD and I find I am changing gears because it is really only workable above 25Hz. I use it routinely at 70 Hz but have run it up to 100 Hz (2880 rpm) and it does not seem to bother it. This motor is scheduled to be swapped out for a 1 HP 1440 240V 3Ph as soon as I can get around to it.

My WW lathe has a 1 HP 415V 1440 PRM running on 1.5kW 240 V Huanyang VSD. I use it routinely at between ~25 Hz and 90 Hz with no problem. Even at 20 Hz it does not seem any warmer than at 50 Hz but I should stick a TC on it to really check this out. I have run this one up to 120 Hz but I can hear what sounds faintly like a bearing noise starting at that frequency which is why I ste the max Frequency on the VSD to 100 Hz.

[gorriss]

My Hercus 9" has 1/2HP 415V 1440 RPM running on 1.5kW 240 V SAJ VSD

My WW lathe has a 1 HP 415V 1440 PRM running on 1.5kW 240 V Huanyang VSD.

So you are running 415V motors on 240V. I presume you would lose a lot of power?

Graham

[BobL]

So you are running 415V motors on 240V. I presume you would lose a lot of power?

Graham


Yep, that is correct
- the original WW lathe had a 1/2 HP 240V single phase motor on it. That's why I used a 1HP 3-Phase 415V running at 240V 3 phase. It may be just my imagination but it seems to be more powerful than the original single phase motor. I suspect the 1/2 Hp motor was not even that - It's still all wired up so I will attach an ammeter and check it out.
- the Hercus 1/2 HP 415V 3Ph is being changed to a 1HP 240V 3phase so it should have a full 1HP available.

For the belt sander I am building I will use a 3HP 415V 3Ph at 240V so it will be ~equivalent to 1.5HP which is fine for a belt sander.

The problem comes when you want a full 3HP but only have 24V 3Phase, as 6HP 415V motors are pretty rare.

[gorriss]

Yep, that is correct
- the original WW lathe had a 1/2 HP 240V single phase motor on it. That's why I used a 1HP 3-Phase 415V running at 240V 3 phase. It may be just my imagination but it seems to be more powerful than the original single phase motor. I suspect the 1/2 Hp motor was not even that - It's still all wired up so I will attach an ammeter and check it out.
- the Hercus 1/2 HP 415V 3Ph is being changed to a 1HP 240V 3phase so it should have a full 1HP available.

For the belt sander I am building I will use a 3HP 415V 3Ph at 240V so it will be ~equivalent to 1.5HP which is fine for a belt sander.

The problem comes when you want a full 3HP but only have 24V 3Phase, as 6HP 415V motors are pretty rare.
So to clarify, the motors aren't dual voltage 240/415 wired in delta for 240V but are actually wired for (expecting) 415V.

[Stustoys]

Simple maths says its about 58% so 3hp becomes 1.74hp. Though I dont know anyone that has tested that.

Bob if you havent already, you maybe able to "boost" the power below 50Hz by changing the motor Hz rating on the VSD (I'll try and dig up the correct number I have it somewhere) so that instead for reaching 240V at 50Hz it reaches 240V earlier matching the v/hz curve of a 415V VSD.. well up to 240V of course. I wonder if it feels more powerful because its constent power rather than push push push from single phase?



So to clarify, the motors aren't dual voltage 240/415 wired in delta for 240V but are actually wired for (expecting) 415V.
Well technically I dont know how the one I use is wired(I could guess but thats not the point). Its a 3 phase 415V motor, expecting 3 phase 415V supply, running on a 3 phase 240V VSD.

Stuart

[Stustoys]

They say it a little better than I could ;)HowTo: 240V Supply to a 400V AC Motor - Application Detail (http://www.inverterdrive.com/HowTo/240V-Supply-to-a-400V-AC-Motor/default.aspx)

[BobL]

So to clarify, the motors aren't dual voltage 240/415 wired in delta for 240V but are actually wired for (expecting) 415V.

Correct.
BTW I wouldn't do this on something like a TS that really does require the full power rating of the motors

[gorriss]

Sorry, what's a TS?

[Bob Willson]

I am almost certain that he is not telling the truth here. The motors are a complete unit in and of themselves, so it should not matter what they are driven by.
This sounds a little like Telstra not taking responsibility for their phone lines unless you use one of their telephones. I would definitely check this out with the ACCC.

I was wrong.
They state both in their operating instructions and also in their warranty that it is mandatory to use their WEG VFDs with their Wmagnet motors.

[gorriss]

Hi Graham
Did you tell him it was 3.1hp at 440V?

Stuart

Just did the maths as you say 3.1hp @ 440V = 2.9hp @ 415V.
I was a little worried as the motor info plate says HP 3.1/2.5 (But actually 3.1hp = 2.3Kw.)
I assumed the 2.5 was Kw which at 415V would equate to 2.35Kw but I think it is hp for the 2 pole or 4 pole set up. So when its half speed (4 pole I presume) it is only 2.5hp. When it is full speed (2 pole) it is 3.1hp. Does that sound correct?
I did ask Dave last night about the fact that is was 440V and he said I can set the voltage on the inverter to 415 or 440 or anywhere in between. So presumably I set it at 415V and it should be OK.
Graham

[Stustoys]

but I think it is hp for the 2 pole or 4 pole set up. So when its half speed (4 pole I presume) it is only 2.5hp. When it is full speed (2 pole) it is 3.1hp. Does that sound correct?

Well I cant tell you which hp is for 2 pole and which is for 4 pole but yes 3.1hp and 2.5hp sound correct. (though I certainly cant explain why).



I did ask Dave last night about the fact that is was 440V and he said I can set the voltage on the inverter to 415 or 440 or anywhere in between. So presumably I set it at 415V and it should be OK.

Ok we really are out of my depth now. I dont believe changing the max voltage on the VSD changes the Max output Voltage at all. As I understand it the max Voltage is fixed by the line voltage. The max voltage number is just used to work out what V and C the VSD should output below the Max.
I think.
Having said that, my Teco doesnt have setting for motor V(though I assume there are many setting I cant get to on the Teco as it only has 30 odd settings, the huanyang VSDs have more like 180 settings)
Having said that if Dave from DD can indeed set the Max V to 415.... you should (I think) be set.

Hows that for dodging and weaving post? :rolleyes:

Please forget my post #50 as its a complete load.
If you had it on 4 pole, running it at 100Hz would still only be 2800rpm:doh:

Stuart

[gorriss]

Hi Stuart
I have to ask...
I am busily trying to sort this all out :? and get my machine working hence my being glued to the PC for hours at a time. What's your excuse?

PS. Don't stop you have been a great help :U

Cheers
Graham

[Stustoys]

Well I do have wireless in the shed but its a little on the warm side out there just at the minute so I havent spent a lot of time out there today. Besides while I read the forum on my tablet or phone I hardly ever reply on them.

Stuart

[gorriss]

Well I am about to seal the deal on the 240-415 inverter from Drives Direct. My 3.1hp motor is rated at 4.5 amps. The inverter is rated at 4.6 amps so it should be OK as long as not in commercial use. The 3.1hp is only for the spindle moulder so shouldn't be a problem. Apparently the voltage and horsepower ratio does not mean anything, it is always trying to produce the same hp and the current draw will vary as required. Looks like about $658 all up including remote POD on/off switch. I hope I've done the right thing?
Graham

[gorriss]

The deal is done!
Being posted tomorrow :U
Do you remember how long yours took to deliver Stuart?
Graham

[Stustoys]

Apparently the voltage and horsepower ration does not mean anything, it is always trying to produce the same hp and the current draw will vary as required.
Not sure I understand that or the "commercial use" comment, but if he is happy it will work and your happy, I'm happy.

Stuart

p.s. I paid for mine on 26/7 3:45pm, it arrived on 3/8

[gorriss]

Not sure I understand that or the "commercial use" comment, but if he is happy it will work and your happy, I'm happy.

Stuart

p.s. I paid for mine on 26/7 3:45pm, it arrived on 3/8
Basically he said if I am not running it 8 hours a day it should be fine. Paid $650 including remote switch and freight. Fair bit cheaper than 2 motors plus VFD plus pulley, and much easier solution. Thanks for the heads up.
Graham

[gorriss]

Dave told me the inverter (240 single phase - 415V three phase 3hp) is rated at 20 amps and should have a 20 amp circuit breaker. I currently only have a 10 amp mixed circuit (lights & power on one breaker) to my shed. I plan to upgrade the main line coming into the shed and put a sub board in the shed. I will have in the shed:

1. The 10 amp mixed circuit
2. The 20 amp inverter
3. Possibly another 15 amp power point would be wise while I am at it.

The 20 amp and 15 amp circuits would be concurrent (ie only used separately) so I guess I need to allow for 30 amps coming in. The distance is about 15 meters. I will get a sparky to hook everything up, but I plan to do all the ground work running the cables and fixing the inverter etc before hand to save on labour costs. I was thinking a 4mm cable into the shed, but will that be big enough? Maybe I should go 6mm? Also given the inverter draws 20 amps, the 240V line from the sub board to that would need to be 4mm I presume?

Also can anyone tell me what wire is required for the remote switch?
Graham

[Stustoys]

Cant help with the 240V side of things sorry. Best ask your sparkie whats needed rather than buy something and find out he wont sign off on it. I guess a second hand sub panel would be against code? pitty I have a couple that might do the job for you.

Pretty much any old wire will do for the control side of things unless you are going to run it in the same conduit as the 3 phase wiring.
Or do you mean how many core?(which remote did you buy?)

A little light reading for you. Bare in mind this maybe out of date but hopefully most of it will be the same. No guarantees though.

Stuart

[gorriss]

Here is a link to the switch I bought. I think my wiring will have to be on the floor, since overhead will be a hindrance to using my machine. I would prefer all in one cable (or flexible conduit). Basically it's an on/off switch and speed pot.
REMOTE SPEED POD ON/OFF for INVERTER CONVERTER for MYFORD LATHE MILL | Drives Direct Inverters LTD (http://www.invertersdirect.co.uk/Product/E2%20Inverter%20rev%20off%20fwd%20pod.1/REMOTE-SPEED-POD-ON-OFF-for-INVERTER-CONVERTER-for-MYFORD-LATHE-MILL)
Graham

[BobL]

Dave told me the inverter (240 single phase - 415V three phase 3hp) is rated at 20 amps and should have a 20 amp circuit breaker. I currently only have a 10 amp mixed circuit (lights & power on one breaker) to my shed. I plan to upgrade the main line coming into the shed and put a sub board in the shed. I will have in the shed:

1. The 10 amp mixed circuit
2. The 20 amp inverter
3. Possibly another 15 amp power point would be wise while I am at it.

The 20 amp and 15 amp circuits would be concurrent (ie only used separately) so I guess I need to allow for 30 amps coming in.

What about dust extraction? - either now or allow for it later. I would allow 15A for this and go for the bigger wiring.

My shed has separate 20A and 35A lines running to it. The DC runs on the 20A line and the machines on the the 35A line

[gorriss]

What about dust extraction? - either now or allow for it later. I would allow 15A for this and go for the bigger wiring.

My shed has separate 20A and 35A lines running to it. The DC runs on the 20A line and the machines on the the 35A line
Getting Carbatec 2hp dust extractor most likely. On special right now for $269. Only needs 10amp circuit. Should do me, so I thought that will run on exisiting mixed circuit.
PS Thanks for the manual, was that from Drives Direct or another model?
Graham

[Stustoys]

You need 6 core wire for that remote(well you maybe able to get by with only 5 as I doubt you'll need reverse???) I use Cat 5 cable for most of my controls but thats only twisted pairs, not shielded. If its all in one conduit the book says it should be shielded cable.

The manual is from Teco, a later version of the one that came with my VSD

Stuart

[gorriss]

I have received my 240-415volt 3hp VFD from Drives Direct, but haven't set it up yet. I have a couple of questions which I emailed to Dave at Drives Direct, but I haven't had a reply to any of my previous emails to date, so I thought it might be better to ask here.

I notice on his wiring diagram (from the web site) he shows a three phase 415V motor STAR WIRED. My motors are Delta wired for 440 volts. Is that a problem? In my case Star wiring requires 760 volts according to the plates on the motors (from memory - something close to that voltage anyway)

The other question. I got a Rev/Off/Fwd plus Speed remote switch. I see how that is wired up. Can an emergency Off switched be wired up as well? (I presume that would require that OFF means a voltage is applied to the pin in question, while ON is no voltage - if it was the other way around it wouldn't work?)

Cheers
Graham

[Stustoys]

Hi Graham,
Your case is a little different to most so yes you'll be running in Delta.

Do you have a Rev/off/Fwd switch? (I just looked at your link and it has a picture of both it and the on/off version, but the listing is for the on/off)


Re E/stop, I dont really like the way the Teco handles E/stop, for starts you have to make a circuit for it to work. But short of adding some extra controls you might have to put up with it.

If the VSD is running and F_19=3 and you connect terminal 12V to SP1 E/stop is activated(you could also set F_20=3 and use 12V to SP2). Once activated the VSD must stop, you then need to remove the E/stop signal and cycle the ON/Off switch to be able to restart.

The manual say the same thing once you decode it

F_19, F_20 =3: External emergency stop

When the external emergency stop signal is activated, the inverter proceeds to decelerate andstop, (ignoring the setting of F_14). The inverters E.S. light will flash after stopping. After theemergency stop signal is deactivated, turn the RUN switch OFF and then ON again to cycle it.(F_10 =1) Or, push the RUN key (F_10=0). The inverter will then resume operation and restart. Ifthe emergency stop signal is removed before the inverter stops, the inverter will still execute the
emergency stop.

Stuart

[gorriss]

Thanks Stuart
Obviously I should have read a bit further in the manual and I would have seen that about the E/Stop. Waiting on my sparky to get a bit more juice in the shed. Will let you know how we go once it's sorted.
Graham

[Stustoys]

First time through many parts of the manual didnt make much sense to me.(in fact some of the settings are still a mystery)

Just watch for typos in the manual, even the Taco manual has a few. So where possible try and find the same info in two places.

Stuart

[gorriss]

Ive got the sparky dropping off some wire and bits and pieces so I can do all the running of cables etc before he comes to hook up a beefier line to my shed. Can I connect the VFD to 240 input without a load attached so I can configure the VFD and not waste time (read money!) when he comes to hook up? I know it's not strictly legal, but do I know the basics of electrics and will just need to connect the 3 wires on the input side. I presume 2.5mm cable is fine without a load since the current draw will be minimal?
Graham

[Stustoys]

Short answer NO.

Longer answer Yes but only if you don't turn the output of the VSD on.
What will happen if you turn the output on with nothing connected is a matter of conjecture some say the VSD is more than able to look after itself and will error and shut down, others say you will let the smoke out.
I wouldnt want to find out on a $500 VSD.

As I understand it, nothing illegal about connecting it yourself if you use a three pin plug.(assuming this is in your domestic shed).

If I recall correctly my Teco ran ok straight out of the box.
Though you might want to make a list of what you think the parameters should be so you can flip through them quickly once you have it wired up.

One thing to remember if you choose to use "controlled deceleration stop" you can't switch from one motor to the other until the VSD has finished braking.

Stuart

[gorriss]

Thanks Stuart

I realised that I could not press Run without risking damage. Probably safer if I just write out all my parameters, and do a quick check before I test it.
Graham

[gorriss]

Looking at the input wiring for my VFD. The manual shows pictures of different looking units to mine that have a nice input setup with a small tube coming out the bottom of VFD with a nut on. I hope that makes sense, it basically allows a double insulated cable to go into the VFD where the individual wires are then hidden inside. On my unit there are connections (L1 and L3) where the live and neutral wires are connected straight to the outside of the VFD. That looks a little dodgy to me with the single insulated wires exposed?

I seem to recall seeing pictures of your setup (Stuart) but I can't find them. Any chance of a link please? Any other ideas how to do this?

Also the manual talks about a SW1 switch that changes the external signal type. I don't seem to have that switch on mine (or I can't find it). I will contact Dave, but won't hear until Tuesday due to the time difference I presume.

Cheers
Graham

[Stustoys]

Hi Graham,

They are all here
http://www.woodworkforums.com/f65/vsd-enclosure-129337/ (http://www.woodworkforums.com/f65/vsd-enclosure-129337/)

Yes I believe these VSD's should be mounted in an enclosure.(if your manual has the same page numbers your box is on page 18-21)

I cant recall SW1, its likely on the PCB under the removable cover(I cant check as that cover doesnt seem to want to come off without removing all my control wiring).
You shouldnt need to change it anyway.

Stuart

[Stustoys]

With a little gentle persuasion I got the cover off.

[gorriss]

It seems a bit strange to me. The enclosure helps, but obviously you still need to access the VFD directly to program it. Do you know if it is legal to wire it up as is? I guess my sparky will soon tell me, but I want to have everything ready to go before he comes if possible.

I just re-read my Quick Start Guide. It says SW1 should be down (default) for potentiometer connection. My remote switch has the speed control, so I guess I don't need to touch it?

PS Thanks for the link/pics Stu

Graham

[Stustoys]

You're best talking to your sparky, for starters you are in another state. Though as I understand it, after the plug you can do what you like.(of course it cant be a workplace and it cant be for sale). Thats not to say you shouldn't keep an eye on safety of course.

It shouldnt be hard to make up a front panel or barrier to keep your fingers away from the AC terminals

Stuart

[gorriss]

HELP!

OK we just got everything wired up. I ran the initial test at 5Hz as per the instructions and that worked fine. Next I stopped the machine (with run/stop button on VFD), changed the frequency to 50Hz and tried again. The machine ramped up but then gave an error OCC (Over current at steady speed). Stopped and powered off the VFD to reset the error. Now I get OCA (Over current at acceleration) whatever frequency I try to run at.

I am hoping this is not too serious, does anyone know what is up?

Cheers
Graham

[gorriss]

UPDATE

I checked my parameters. V/F Pattern was on 60Hz so I changed it to 50Hz. (Could that have caused a problem when I ran it at 50Hz before?). My machine has 2 motors so I tried the other one (spindle moulder) that is working fine. If I isolate back to the planer/thicknesser/saw motor I still get the OCA error. Found an internet post with same error and someone suggested the possibility of a grounded phase. I presume checking connectivity between each phase and earth will isolate that problem. Will check it out. In any case it appears the VFD is OK which is good news.
Graham

[Stustoys]

Hi Graham,
I assume the planer/thicknesser/saw motor has a lot more spinning mass than the spindle moulder?
Whats F_01=?
Thats your acceleration ramp time. Try making it larger until the OCA error goes away.

Stuart

[gorriss]

F_01 was on 5 by default. I tried 10 with no success. Dave suggested I take the belt off the motor and see if it starts with no load. Could be a bearing or just too much load. I will let you know how we go. Just a bit wierd that it started the first time, but not after that?

Cheers
Graham

[Stustoys]

Sounds like a good plan.

Whats F_05=?

Stuart

[gorriss]

Good plan, but no joy. Removed the belt and motor spins freely by hand, but still get OCA error. F_05 was default on 4. I changed it to 1 but that was after the error had happened. I thought it should be on 1 since we are at 50Hz here, but Dave said it should be on 60Hz (F_05=4).

It seems that something has happened to the motor, since the other one works fine. It errored on OCC the first time I tried to run it at 50Hz. Is there anything I can do to test the motor?
Graham

[Stustoys]

Did it error at about the same Hz?
How long into the 10 second ramp?
I think you'll need someone with a megger tester to have a look at it.

Stuart

[gorriss]

Hi Stu

The error comes up immediately I press Run. I just tested with my little Dick Smith multimeter. Removed all the Delta connectors and wires so I could test each coil separately. All 3 coils measure 10 ohms, No leakage between any coil to earth. Testing coil 1 to 2 shows no connectivity. Testing coil 2 to 3 shows no connectivity.Testing coil 1 to 3 does a funny thing. When I first touch the contacts, the meter flashes to around 150 ohms, then shows 1 (no connectivity). Maybe this is showing a potential problem.

Dave said I might need a megger. I don't know what that is?

Interestingly the motor that is working has been rewound while the previous owner had it. Te one with the problem is original I think.

Cheers
Graham

[Stustoys]

We are heading out of my depth.
Your multimeter tests resistance at 9V
As I understand it a megger tester does the same but in this case something around 500V(maybe a more)

Someone that knows more might be able to explain the 150ohms thing.

Might be time to take it to a motor rewinder, they will have the gear to test it.

Stuart

[gorriss]

Yes I did some googling and it appears you need to test at higher voltages to diagnose properly. This really sucks. If only it was the other motor I could still use the machine! I guess electricians are the only people with meggers? Pity I didn't get him to test when he was here, but I thought it was probably a VFD problem since I hadn't tried the other motor at that stage. This might get expensive. I guess the motor might have been ready to go, but presumably the VFD tipped it over the edge. I think its probably cheaper to buy a new motor than rewind. I live in a remote location so that is a problem for me. I really just need to know if the motor is cactus or not.

Thanks again for your help
Graham

[Stustoys]

I'm not sure if many electricians would have a megger tester??
Only thing I can suggest now is testing coils 1 to 3 in all four possible ways. Though I dont know if it will tell me anything it might help someone else. You might find its shorted in one of the four ways? Who knows maybe if you are luckly its a wiring problem before the windings.

Isnt this the motor with the strange shaft?

Stuart

[Stustoys]

Something just dawned on me. If it is happening as soon as you hit the run button you might be in luck.

As I understand it. As the output V is related to Hz, if the VSD is erroring as soon as the run button is pressed. To me this would mean the V was something less than 10%. Now to have over current at that V and Hz would be something above 60% of the VSD's rated current. I would have thought the fault would need to be close to the end of a winding or before the windings. Now if its "close to the end" that does you no good at all. Before would be a good thing.
And of course I may have the above completely wrong. With luck someone that knows what they are talking about will show up.

Fingers crossed.

Stuart

p.s. whats F_18=?

[gorriss]

Interesting that you say that. I was on the phone to WA Rewinds and he reckoned the weird thing happening on my ohm meter might indicate a faulty connection. I removed the junction box on the motor and got behind it to have a look. Most of the wires going to the junction box from inside the motor have cracked insulation so that I can see bare wire in places! The problem may be well before the windings if that is the issue. There doesn't appear to be much spare cable to re-terminate and I am not sure how the wires are actually terminated to the brass screw connectors. Looking on line and I am waiting to talk to the rewind guy again. I guess the whole motor may need to come to bits to install new main wiring?
Graham

[gorriss]

OH OH!!!!

Pulled the terminal box on the faulty motor and attempted to insulate the wires for the couple of inches I could see. Wired it all up and gave it a go.

A BIG BANG from the VFD and tripped out the whole shed! Must have been a short further down the line I am guessing. The VFD now comes up with a LV error (looks like LU but presume it is LV). Manual says "Voltage too low while not operating". Detection circuit defective. Return the inverter for repair.

I think I was trying to be too clever for my own good. I guess now I will have to send it back to Dave. Do you think he will repair it under warranty?

What a saga :(

Graham

[Stustoys]

Not good.


Do you think he will repair it under warranty?
Well not if he sees this thread.

Did you check the resistances at all before you fired the VSD up?

My only guess is you've blown the voltage doubler side of things........ but that's just a WAG.

Stuart

[gorriss]

Stupidly I didn't recheck resistances. Emailed Dave and was pretty up front with him about what happened. Just have to see what happens. If Dave won't warranty it, could I get fixed somewhere here you think.
Graham

[Stustoys]

If Dave won't warranty it, could I get fixed somewhere here you think.

That would depend on what Dave has put in there, I have no idea. It could be something pretty simple, I think it can be done with a couple of caps and a couple of diodes........but I have no idea how complex they can get. Also it would depend if he has removed part numbers or encapsulate pcd boards etc to make your life hard. And of course its only a guess that its his mod that has failed. If its the VSD you might be able to find someone to fix it.

Stuart

[gorriss]

No warranty so I opened it up after asking Dave. Sent him a pic but to me it looks like its just blown a couple of tracks on the circuit board. I can't see any damaged components, but I guess one might not be able to tell just by looking at it, but I will wait to see what Dave says tonight. I might be able to repair the tracks and be back in business.

Interestingly I mentioned to Dave thet the VFD blew up as soon as I powered it up. I didn't get to try running the motor. He reckons the damage was done before I tried to fix the motor - on the previous test, and then it blew next time I turned it on. To quote his reply when I asked if it was normal to blow up when I hadn't pressed run...

"YES it is normal as its likely the damage was done before the last test and shorted an output transistor"

Anyway, I have a little hope that I can repair it, otherwise he will replace it at cost for me.

Graham

[Stustoys]

Missed this becuase I was using my tablet. :(

Got any pictures of the damage?(besides I've not seen inside one of these)

Stuart

[gorriss]

Hi Stuart

Sorry for the late reply. Been working and got family visiting.

I only have one picture of the damaged track section which I have attached. (It looks quite small after I uploaded it so I hope you can see it?) Soldered up the tracks that were damaged and plugged it all back in now. No more "bangs" but still getting the LV error when I start it up. Incidentally, Dave said there is no problem starting it up without the load wires attached, and I could even run it like that without damage.

Looks like I am up for a new unit, so if I get one I will show you the innards of the old one at some later point. Probably need a new motor as well, but I just remembered an old friend who does rewinds. I will talk to him to see if it is feasible for me to fix the faulty wiring on the old motor. The worry is that if the windings themselves have any problems I could blow another VFD! I reckon the 4 hour drive when I bought the machine must have caused the old internal motor wires to break up the brittle insulation.259570

Cheers
Graham

[Stustoys]

Hi Graham,
The picture is fine once opened in another window.
As I understand it a megger test will tell you if the insulation in the windings is any good. The cracked insulation you've seen doesnt go very far into the motor and would be easly replaced by someone with the right gear.
Once you replace one motor (and this is the tricky one correct?) it might just be easier to replace both and go with cheaper VSDs?

Can't tell from the picture if its Daves or a factory board(I'd guess factory). I'd say this cap is toast also, but replacing the parts that look blown likely wont get you anywhere... how would you know what value C240 was? and that may just be the start of it. Still you never know your luck.
Thing is sending it to someone that knows what they are doing would likely cost more than a new one.

Stuart

[gorriss]

Hi Stuart

Yes I thought about replacing both motors. The problem is that the good motor is a 4 pole (2 speed) for the spindle moulder and I want to keep that speed option. Yes I could do it with a cheap VFD I spose. Also the current good motor is a 100L frame with a bigger shaft than most 3hp (90L frame) motors. So I have the problem with my belt pulley not fitting. Also, that motor has been rewound already. I think I might phone the guy I bought the machine off and get a bit more info about the rewind. Plus I can mention the problem with the other motor (not that I expect much redress). Two motors would be around $600, plus a cheap VFD maybe $200 - $800 total? Dave said he will do me OEM price for VFD which I am hoping will be under $500 including the 75 for freight. One new motor at $300 and I should be up and running (also about $800), and no dramas with pulleys. So those 2 options are both around $800 anyway. What do you think? Are there worries if I go the cheap VFD route. All the suppliers I talked to reckon around $500 for their VFDs. I know there are cheaper on ebay, but what if they blow my new motors?

I am open to your thoughts. If it wasn't for the 2 speed motor I would just buy single phase motors and be done with it.
Cheers
Graham

[gorriss]

Got a price for a replacement VFD from Dave. Still not that cheap, so considering the option of 2 new motors and cheaper 240V VFD. Can you tell me are there disadvantages to running the motors in star config (240V) rather than delta (415V). Presumably there would be a higher current draw. My original VFD drew 20 Amps. Will a 240 - 240 model draw more?

Also I still have the problem that my good motor (2/4 pole 440/760V) is a 100L frame with 28mm shaft diameter. A 2 pole motor (with VFD for speed control) would be fine but they only come in 90L frame and my belt pulley won't fit the 24mm shaft. I am waiting on a price for 2/4 pole motor. Probably cheaper to keep that motor and go with Dave's VFD, but dead scared of blowing up another one. That other motor did run without fault though, so I am obviously a bit paranoid!

Cheers
Graham

[Stustoys]

Hi Graham,
I'm a little confused
I'm thinking you have it backwards(but maybe you mean something else?).

Should

"Can you tell me are there disadvantages to running the motors in star config (240V) rather than delta (415V)."

read

"Can you tell me are there disadvantages to running the motors in Delta config (240V) rather than Star (415V). Presumably there would be a higher current draw."?

As I dont think you arent likely to find a 240V star motor, thats not to say they arent out there. Though you might find 415 Delta pently of those from 3hp and up.

Assuming its the later and you are talking about running a motor either in Delta on a 240V VSD or in Star on a 415V VSD. The input current would be about the same. Both are outputing 3hp so the output current of the 240V VSD would be double the 415V VSD, but the input would be the same.(or there about............I think)


I think the first thing I would to is get the bad motor checked out and find out if its a cheap fix or a rewind/replacement.

You could price getting the good motor rewound for 240V at the same time.

Then just do the maths


Stuart

p.s. The rewound motor was wired in Delta when you got the machine correct?