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Thread: Question for the VFD Guru's
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12th Sep 2017, 07:13 PM #16Most Valued Member
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For you? Nothing really*, its referring to 3 phase 220V. I'd hoped there would be a 220v primary tap for that reason, but it sure doesn't look like it.
Stuart
*other than the wiring maybe ok for the current you'll be drawing using 1/2 the V(though I wonder if anyone has built a mill with wires sizes that close??)
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12th Sep 2017, 10:06 PM #17
Just one more option: You can sometimes find 240 to 415V transformers. Once you have 415V (single phase), you have the option to use a suitable 415V VFD to generate the 415V 3-phase. That would allow you to use the 2 speed motor you have as is. Sadly, the Delta - 2Y motors can't simply be wired for 240V 3-phase.
I've just gone through that exercise - successfully so far. I found a 1kW transformer, bought a used 415 2.2kW Lenze VFD and found that it is happy to run on single phase. I'll restrict it's output to the 1kW input I can give it, that way the rectifier diodes stay within their limits. The other thing that I hadn't expected is that the Lenze VFD is explicitly suitable for motor-side switching! That means I could switch the motor speed while the VFD is running!
Interesting new option....Cheers, Joe
retired - less energy, more time to contemplate projects and more shed time....
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12th Sep 2017, 11:22 PM #18Most Valued Member
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Hi Joe,
I like!
That would sort out his transformer issue at the same time.
Going to have to keep my eyes out for one.
Hi Shane,
You've got a 3 phase coolant pump at a guess. Not much of an issue though.
Stuart
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12th Sep 2017, 11:47 PM #19Sadly, the Delta - 2Y motors can't simply be wired for 240V 3-phase.
Dean
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13th Sep 2017, 12:53 AM #20
Hi Dean. You'd better tell us how! pretty please
Was it a 240V 3-phase motor made for the US? or did it start off as a 415V 3-phase motor made for Australia/Europe and rewired to 240V (without being rewound)?
BTW, I do know of a theoretical way of rewiring the latter, figured out by RayG, but there are so many embedded coil ends involved, I've never managed to do it without stuffing up the insulation....Cheers, Joe
retired - less energy, more time to contemplate projects and more shed time....
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13th Sep 2017, 07:06 AM #21
So if I run a VFD on a 415v 3 phase I will get half the speed and half the torque is that correct.
Also what happens if you use a larger VFD say a 2.2kw instead if a 1.5kw.
What if I just run the high speed winding on the VFD and not the low speed. Just exploring all options as there are many differing opinions on Google.
Need someone to explain the difference to me, at the moment I have a HM-45 running fine on a VFD, the plate of the motor and the vfd I am using are below, this has been running happily for 3 years.
it is a 1.5kw vfd running a 1.5hp (1.1kw) motor and the motor appears to be 415v
DSC_0021.jpgDSC_0022.jpg
Let's forget about the Power Feed, I have a 240v to 110v transformer that will take care of that.Shane
Got the square peg in the round hole, now can't get it out !!
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13th Sep 2017, 09:24 AM #22Most Valued Member
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If you run a 240V VSD on your mill as currently wired(i.e. for 415V) you will get about half the torque(i.e half the power) all the speeds will be about the same. Its unlikely you will have the same range of speed adjustment with the VSD before power gets to low to be much use.
If you run a 415V VSD on your mill as currently wired(as Joe said above) you will have full power and a larger speed range.
A larger VSD won't help. (infact I think if you were sure you were going to run it on 240V but wired for 415V you could in theory use a smaller VSD)
I dont see how this makes any difference, other than "not having switching after the VSD" which some people worry about. Its not an issue as long as they VSD output is off when switching speeds, and in some cases it doesnt even have to be off.
Many single speed 3hp and below 3 phase 415V motors can be easily rewired to run on 240V.(
Most other single speed 3hp and below 3 phase motors can, with a little work, be rewired to run on 240V.
They are Star wired, thats the Y on the bottom left of your HM-45 motor plate. They are rewired to Delta Δ to run on 240V.
2 Speed motors are different, they aren't nearly as easy, if at all. Now it maybe possible(re Dean above) but it would be at least 3 times as much rewiring. I'd have a chat to a motor rewinder and see if they are interested in trying and how much they would want, prices are all over the place.
Hope I've made things better and not worse.
Stuart
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13th Sep 2017, 10:32 AM #23Member: Blue and white apron brigade
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You need to remember that while running, a motor does not constantly produce it's rated power, the power output depends to a great extent and up to a point on the load and not many machine users operate their machines at full load capability.
In other words this just means that the the HM-45 has not been loaded up near the 1.5HP output ability of the motor.
If most of what you are doing only needs half the 1.5HP then you would never know there was a problem.
On the odd occasion when the load was such that the motor needed to deliver a bit more than 0.75HP it was able to do this provided you did not do this for too long.
If the over loading is done in short bursts depending on the motor you can probably do this for a few years and get away with it.
OTOH if the load is constant, such as on a pump, the motor will degrade and die sooner or later.
I ran my WoodW lathe like that for a few years as all I was doing was small spindle work which doesn't need much power/torque.
While we are talking VFD's I have been dealing with Powtran in China to purchase a decent quality 3P-3P VFD.
I started out trying to go through their Alibaba portal but that was hopeless so I approached them direct and their response has been EXCELLENT.
Powtran's latest entry level Vector Drive VFDs (PI9130A series) are full vector drive with the braking circuitry built in, dual speed potentiometer, dual displays and a host of other features - most of which we will never use.
The standard large red LED display shows any value that a machine operator would need to see, while the smaller 4 line OLED (multi-lingual) display screen shows other parameters and is useful for programming. These are much more ruggedised units than the comparable Huanyang VFD models and given the quality the prices are very reasonable.
Their 220-380V prices are
Their 1.5HP model (1R5G1) is US$115
The 3HP (2R2G1) is US$129
5HP (004G1) is US$160
Delivery via DHL is US$40
I ordered a 1.5HP 3P-3P VFD (1R5G3)and it was the same price as the 1R5G1.
So for a total of AUS$200 I get a full vector drive VFD with a host of useful features.
The contact email is [email protected]
The Persons name is Nicole Chan.
Back in May in the woodwork forums I did a side-by-side comparison of an older model Powtran (PI9100 series) with the HY and you can see some of the differences.
The old model had dual LED displays whereas the new one has an LED and an OLED screen
VFD install summaries
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13th Sep 2017, 10:55 AM #24Most Valued Member
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13th Sep 2017, 10:57 AM #25
How? Pretty please? I have no idea. I just hooked it up against the recommendations from the forum and it worked.
It is a Chinese built motor/lathe (CY) sold in Australia. The motor (original) is as I have said, Delta - YY. It is rated for 415v. It had a 2 speed switch. I started by just connecting to the VFD in Delta. All worked perfectly. Quite some time later I connected the VFD to star just to see what happened and it worked fine at full speed. Now I have contactors set up and have put the 2 speed switch back in to switch them. I don't have protection from changing speeds while it is running. I rarely use high speed, but it is there when I need it.
I think it is a good idea to just try a motor before doing anything expensive and irreversible. Sorry I cannot help anymore than this. When I first started asking on the forum about connecting this motor to a VFD I was told it would not work. Knowledge has improved since then. It is a very complex subject tho.
Dean
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13th Sep 2017, 11:03 AM #26
Bob,
Are you referring to 220v 3P - 380v 3P VFD's with all of those listed?
Dean
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13th Sep 2017, 11:11 AM #27Most Valued Member
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As I recall the original idea was for you to run your 415V motor on 240V to limit the power output, there by limiting the input current required as at the time you couldn't supply the current needed to run at full power.
Yes some people get bent out of shape about switching after the VSD, they still do I believe. As for interlocking, how many people have protection from changing gears while running?(yes some laths do but many/most don't)
But unless you've done a lot of work to the motor, you wont be getting full power, just full speed(subject to what Bobl said above about getting more power for short periods) which given the power of your lathe isnt likely to be an issue all that often. But then. you never claimed full power.
Which I think is what Joe was thinking.
StuartLast edited by Stustoys; 13th Sep 2017 at 11:15 AM. Reason: added quote
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13th Sep 2017, 11:56 AM #28As I recall the original idea was for you to run your 415V motor on 240V to limit the power output,
But unless you've done a lot of work to the motor, you wont be getting full power, just full speed
Initially I only had a 10A circuit to run the lathe from. I have now installed a 32A circuit, but I only have a 15A GPO as I don't believe I will need any more than that.
Dean
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13th Sep 2017, 12:07 PM #29Member: Blue and white apron brigade
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13th Sep 2017, 12:14 PM #30
Is there a problem if you use a larger rated VFD than needed, say 2.2kw or even larger when you only need 1.5.
On my HM-45 it has a 1.1kw motor and I am running a 1.5kw vfd and never had an issue.Shane
Got the square peg in the round hole, now can't get it out !!
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