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bollie7
8th Jul 2017, 09:29 PM
Gday Everyone.
I'm looking at getting a vfd to run my 3 phase mill on single phase. I've been doing a lot of reading here about these beasties and the more I read, the more confused I am becoming (that seems to happen a lot easier these days).
I intend to replace the old, original two speed motor with a single speed 2.2Kw Teco motor that I have.
My understanding is with the motor I have, when its configured in the Delta mode, it requires 220-240V three phase power. Is that correct?

368708

So would something like this (https://www.aliexpress.com/item/HUANYANG-VFD-inverter-2-2KW-motor-220V-7A-Vector-control-frequency-converter-Optional-parts-extension-cable/869715792.html?spm=2114.search0104.3.32.o8AbV4&ws_ab_test=searchweb0_0,searchweb201602_1_10152_10065_10151_10068_10130_10084_10083_10080_10082_10081_10136_10110_10137_10175_10111_10060_10112_10113_10155_10131_10114_10132_10133_10154_10056_10055_10054_10182_10059_100031_10099_10078_5360019_10079_10103_10073_10102_10189_10052_10053_10142_10107_10050_10051,searchweb201603_5,ppcSwitch_7&btsid=2a135553-a26d-4a89-b95a-a47e3f66336c&algo_expid=f75b3ff2-109e-4bf7-a3d1-61f17db00b62-4&algo_pvid=f75b3ff2-109e-4bf7-a3d1-61f17db00b62)be suitable for my motor?

The other question I have is how do I work out what size 240v circuit do I need? 15A - 20A - 25A ?
My son who is an eleco but lives interstate, is coming for a visit in a couple of months so I would like to get the cable run and have all the bits (for the dedicated circuit) ready for him to connect up.

Any advise would be greatly appreciated.
thanks in advance
Peter

BobL
9th Jul 2017, 12:01 AM
The only reason for using more than 10A (usually 15A) GPO on a 3HP/2.2kW motor are the start up currents. If you program the VFD to have a slowish start (3 secs) you can run that motor via a VFD from a 10A GPO.

Oldneweng
9th Jul 2017, 01:32 AM
My understanding is with the motor I have, when its configured in the Delta mode, it requires 220-240V three phase power. Is that correct?

Yes. A 3ph motor wired in Delta will only be supplied 240v from the 415v 3ph supply because of the way Delta works. A VFD will supply this 240v. This is why Delta motors are usually recommended.

My lathe has a 7.5hp motor and the biggest current I have seen it draw is 12A and that was just when I was running it pretty fast while trying it out. It is also a 2 speed motor (Delta, YY), and works in both speeds via the VFD.

Dean

bollie7
9th Jul 2017, 10:44 AM
Thanks for the info gents.

That has reduced the cost a bit for me already as I already have a 16amp breaker and a 15 amp GPO.

Do you have any thoughts as to the VFD I linked to?

thanks
peter

BobL
9th Jul 2017, 11:17 AM
Do you have any thoughts as to the VFD I linked to?

I have 5 of those VFDs on machines in my shed. They are basic VFDs and should be fine for what you are doing.

bollie7
9th Jul 2017, 08:46 PM
Thanks for that Bob.
Another question
These (http://www.ebay.com.au/itm/2-2KW-3HP-10A-220VAC-SINGLE-PHASE-VARIABLE-FREQUENCY-DRIVE-INVERTER-VSD-VFD-AUS-/121224071334?hash=item1c398488a6:g:3NoAAOSwEzxYeYVN) are currently on ebay. They look very similar to the Huanyang one but slightly cheaper. (More than likely a different brand)
The slight difference in price doesnt bother me but the ebay ones are listed from a seller here in Australia where as the Huanyang is in China.
I'm wondering if you or anyone has had any problems with the Huanyang and if so how was it resolved from a warranty perspective?

I'm just thinking its easier to return something to an Australian address than a China one.

With the Huanyang unit I notice they say that they say that a braking unit is an optional extra. I dont envisage me wanting to use the machine for power tapping so is there any real need to have a braking facility? I know it might be nice to have, but essential - probably not.

Thanks for your patience in answering my questions

peter

BobL
9th Jul 2017, 09:32 PM
Thanks for that Bob.
Another question
These (http://www.ebay.com.au/itm/2-2KW-3HP-10A-220VAC-SINGLE-PHASE-VARIABLE-FREQUENCY-DRIVE-INVERTER-VSD-VFD-AUS-/121224071334?hash=item1c398488a6:g:3NoAAOSwEzxYeYVN) are currently on ebay. They look very similar to the Huanyang one but slightly cheaper. (More than likely a different brand)
The slight difference in price doesnt bother me but the ebay ones are listed from a seller here in Australia where as the Huanyang is in China.
I'm wondering if you or anyone has had any problems with the Huanyang and if so how was it resolved from a warranty perspective?

I'm just thinking its easier to return something to an Australian address than a China one.

With the Huanyang unit I notice they say that they say that a braking unit is an optional extra. I dont envisage me wanting to use the machine for power tapping so is there any real need to have a braking facility? I know it might be nice to have, but essential - probably not.

Thanks for your patience in answering my questions

peter

They are the same unit but note they don't have a potentiometer to control speed - you would have to add that yourself.
And the other ones come with an extension cord and remote control panel holder.
All up it doesn't add up to a lot (i.e. <$10) but that depends how deft you are a basic electronics.

I haven't had any problems with these so warranty hasn't come up yet.

To add the braking unit is not a job for the faint hearted.

bollie7
9th Jul 2017, 10:17 PM
Thanks Bob.
I'll probably go with the Huanyang then. Interestingly, only one pic of the Huanyang listing shows a potentiometer, all the others its not there.
Thanks for your help.

regards
Peter

Pez
9th Jul 2017, 10:24 PM
Those units run askpower firmware. They work fun, but they do have some quirks (e.g. if you set min freq too high it will trip on overcurrent).

Most of the small units don't actually have the capacity to add an additional braking resistor, but the internal resistance will slow down a mill etc at quick enough for most.

Note that most larger 415 motors don't have 240v delta windings, read the plate carefully.

Lots of those 'AU' sellers (like the one I bought from) are in China anyway. Mine had china post labels.

Pez
9th Jul 2017, 10:27 PM
Oh and when you run in single phase convert the output power to the current on the input side to get the equivalent capacity.

bollie7
9th Jul 2017, 10:29 PM
Ok. I've just ordered the Huanyang.
Hopefully the delivery will be closer to the 10 day period than the 32 day.
Then the fun will begin.

peter

bollie7
9th Jul 2017, 10:31 PM
Oh and when you run in single phase convert the output power to the current on the input side to get the equivalent capacity.
Pez, 1st off, Welcome to the forum.
Can you add a bit more detail to what you said please? I dont understand what you mean. I know enough about electrics to know that I dont know much.

thanks
peter

Pez
9th Jul 2017, 11:38 PM
Hi Peter

Sorry - that was a terrible explanation! I've been a lurker for ages but posted from having the same struggle years ago. Not an expert but happy to share what I've learned.

Basically the way the vfd's work is they put the line voltage through a rectifier and convert to DC. The DC charges some large capacitors, which creates the 'DC bus'.

This is then fed into mosfets (think fancy silicon relays) that then switch on and off to make the three phase output.

If you take the full load three phase current off the motor (e.g. 8.7A) multiplied by sqrt(3) that's your single phase input current.

You'll only draw full load amps when you are really working it hard, so I wouldn't sweat an amp here or there.

Some units that are 'single phase' models already have this derating but most don't. Just err on the side of larger - you'll get better filtering and larger capacitors out of it regardless.

Pez
9th Jul 2017, 11:39 PM
Oh, and if you're planning on a dro use shielded cable - vfd's are really noisy electrically.

Last tip - never ever unplug the load side with the inverter on. The feedback circuit will try to go to infinity and potentially let the smoke out.

bollie7
10th Jul 2017, 07:08 PM
Pez
Thanks for the info.
I'm removing the old 1.5Kw , 2 speed motor and replacing it with a single speed 2.2kw motor. (motor plate pic in my first post) It definately says 220-240V when in Delta mode.
re the DRO & shielded cable. Do you mean shielded cable on the DRO or on the motor?

thanks
peter

BobL
10th Jul 2017, 11:26 PM
Between VFD and Motor.

BTW I don't have any shielded cable on any of my VFDs.
It plays havoc with AM reception but shielding makes no difference as he noise comes back down the mains cable.
I solved the radio problem say getting a digital radio

I would use the shielded cable if I could get it cheap.

Pez
11th Jul 2017, 03:54 PM
You should be able to get it for about $7.50 from most electrical wholesalers. I only run a short lead from vfd to motor so it's cheap enough.

bollie7
24th Jul 2017, 07:59 PM
Well, in what was a bit of a record for me, my VFD arrived from China in7&1/2 days.
I didn't get a chance to do anything with it until last Sat when I was able to wire it up and check it out.
For a VFD novice I was a bit apprehensive at first as, after reading the "slightly better than engrish" user manual, I was more than a little confused.
So I went through the setup in the book and was quite surprised when it ran first time. I had a bit of a problem getting it to run properly using the potentiometer on the front panel (initially could only get it to run at 25.05Hz max) but did some net research at lunchtime today and found some good info. Changed a couple of settings just now and the pot is now working fine.


So yesterday arvo, knowing that it will run, I pulled the old motor off the mill,and started working on the new motor flange. The "new" motor I have is a Teco 2.2Kw that I bought at a swap meet about 9 years ago for $40. It was almost new. It has a foot mount on it which is not suitable for the mill. I thought I was going to have to fabricate some sort of adapter for it but about 10 months or so ago I contacted Teco in Sydney to ask about a flange mount for it. Thinking it would probably be more than I wanted to spend. Anyway it turned out they did have one and it could be mine for $30. So of course I grabbed it. It actually cost more to get it freighted up from Sydney than what it cost. I think they sold it to me at the “old ,when it was new years ago, price”, just to get rid of it.

The new flange had a location spigot on the bottom so I set it up in my lathe and machined that off as its not required in this set up

It also has four 15mm dia mounting holes on about a 215 PCD. Of course the mounting holes on the mill are on a larger PCD. 236m.
I thought I was going to have to get the edge of the flange built up to give me enough to drill new holes but when I pulled the studs out of the old motor they were stepped. The bit that goes in the motor is only 10mm dia and the other end is ½” Whit. (huh? yes ½” whit – on aTaiwan built machine – everything else is metric - go figure)

So all I had to do was machine the studs back a bit to increase the length of the 10m dia portion and drill new holes in the motor flange. Haven’t quite broken through on the edge of the flange but I’m confident they will be ok. All the loads will be rotational so should be fine.
On the old motor the shaft is 22mm with a shoulder that the pulley goes up against with the end of the shaft being drilled and tapped with a retaining bolt holding the pulley on. I really don’t want to start machining the new motor rotor so I think I’ll bore the pulley (there is enough metal there) and recut the keyway. Might drill and tap a couple of grub screw holes as well. When it goes together for the final time I’ll throw a bit of loctite retainer on it. It should out last me then.

So a fruitful afternoons work yesterday. After not having done much for the last 9 years or so, I have forgotten a lot about machining though. Also lost a bit of confidence. I really have to think things through now where years ago it was almost automatic.

peter