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It is posible to reverse a motor with 1ph in VFD?

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JFV2009

Industrial
Nov 23, 2009
4
Hi there,

This is a basic question probably.
For the application I am building a 220V 3ph motor of 0.125KW should be enough (it is connected to a gearbox).

I need to change direction of the 3ph motor. I have seen on the market ABB inverters that accept 1phase 220V as the input and have a 3phase 220V output to the motor... or either I am misundestanding the user manual.

Is it possible for the inverter to change the rotation direction of the motor when only L1 and ground are available as input?

Does the VFD shift the phases internally? I mean, doest it have capacitors and the stuff required to create 3 phases from just one phase and then swap them to reverse the rotation?

Like for example the ABB ACS150-01U-02A4-1

Or should I buy a bigger VFD with 3ph input, 3ph output?

If this question or similar was already answered, please point me to it.


Thanks a lot for your help



 
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Yes. There are many VFD's on the market which accept a single phase input, and output a three pahse power to the motor. And yes the VFD can electronicly reverse the phase rotation, reversing the motor's direction of rotation. BTW there are less expensive VFD's than ABB. Try
 
We should avoid selling here, that is a good way to get bumped. He did not ask for suppliers.

But back to the technical issue, djs is correct. Any VFD will reverse a 3 phase motor, you do not need to over size it. The issue of over sizing has more to do with the 1 phase input. If the VFD already says it is capable of 1 phase input, then you do not need to over size it. If it does not, you need to double the size.

But you have a different issue as well. You said;
"Is it possible for the inverter to change the rotation direction of the motor when only L1 and ground are available as input?"

This is NOT a valid input connection! You cannot allow the Ground to act as a current carrying conductor, you must use neutral. If you are in the US, the added problem is that L1 to Neutral would be 120V, not 240V. So you must use a VFD rated for 120V input, 240V output (they exist) or use a transformer to step the 120V up to 240V, or find an L2 to connect to somewhere.

More importantly, the fact that you made these mistakes indicates that you are not familiar with these issues. I highly suggest you engage the services of an electrical professional before someone (or something) gets hurt.



"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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You can also swap any two wires that go from the VFD to the motor and the motor direction will be reversed. You generally do this because it allows the VFD direction to be logically correct.

An example would be a water pump. When the VFD is going "forward" would be when the pump is turning the correct direction. Note that you have to wait a while after turning off the power to a VFD before messing with the output wires.

Keith Cress
kcress -
 
Yes, but do NOT swap the leads when the VFD IS RUNNING :)




"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376
 
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Note that you have to wait a while after turning off the power to a VFD before messing with the output wires.

Keith Cress
kcress -
 
I don't read everything, you know that Kieth... [reading]




We need an Emoticon for embarrassed...
 
all vfds have a function to just reverse direction of the motor. Not sure why your making it more complicated than it is?

Why all the bad karma to give to someone just because they are asking for something that is there and maybe they are a bit ignorant?

 
Keith proposed the professional approach to motor control.
Wire the motor so that the load is driven forward when the VFD is in forward mode. It will work the other way but may cause a lot of bad karma.


Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Dodgy cooking in an Indian restaurant... now that's bad korma. [lol]


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If we learn from our mistakes I'm getting a great education!
 
OK Thanks,

Yes somebody has spotted me! I am a nebbie. That's just the reason why I am asking such questions. I did a mistake when explaining the issue: I have 220V L1 and Neutral and also 3ph 380V available. I was just wondering whether to go with a small 1ph VFD or go straight with a 3ph 0.37KW VFD for a "simple" 0.125KW project where a little PLC Siemens Logo controls a VFD with two wires for FW and REV, but I couldn´t find VFDs smaller than 0.37KW-3ph which is 3 times bigger than what I need in terms of power and also I need to reverse rotation.

Since I am not an Electric engineer the only way I knew to reverse the rotation of a electric motor is to swap 2 out of 3 ph. I knew that VFDs do it when 3ph are available at input but I didn't know that it could be done when just L1 & N are available. Now I know that it is possible.

Thanks a lot for the answers and your time.




 
jfv2009
a simple switch between terminals 5 and 9 will provide a forward or reverse rotation of the motor using the ACS150 drive. Son't mess about with switching cables on the mains supply..
 
Hi,

I don´t have it yet. I need a 0.125KW to move a small (light)carriage forward and backwards.

This kind of motor is cheap, I guess that I could go for a DC one but it is more expensive (I believe), I need a different controller, I need an aditional power supply and I'd have to check if it fits the gearbox (it will be connected to a high reduction ratio gearbox) so I thought that for this application a small, cheap 3ph motor driven by a VFD could simplify a lot the system. Everything would come off the shelf, VFD are standard, cheap etc. 2 wires would do the job with a pre-set speed and just 2 outputs (out of four) of my little LOGO! would be used leaving the others free, that's it.

I have attached the info of the motors I am considering. The one I am interested on is CHT 63 A4. as you can see is not the smaller 3ph on that table, there is even a smaller one of 0.09KW.

Thanks


 
 http://files.engineering.com/getfile.aspx?folder=66929f60-9a37-48f2-8575-01af6de4404e&file=CAT-CHB-MOTORREDUCTOR.pdf
Hatachi makes a 1/4 Hp, 0.2 KW VFD P/N X200-002NFU1
 
Thaks a lot to all for the comments and help....

I´ll be back... probably with some more basic stuff.
Thanks

 
Just so you know, many (most?) VFDs that small are now ONLY available with 1 phae input, so even if you have 3 phase available, the installation manual will show that you feed t with only 2 of the 3 phases (or in your case, Phase and Neutral). This is because below a certain size, circuit conductors cannot get any smaller, so to use 3 phases saves nothing and single phase supplies are so common in that range, the demand is there for the power semiconductor suppliers to only produce the IPM (Integrated Power Module) that is set up for 1 phase input.

So in other words at that extreme low end you are looking for, it may be a moot point.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376
 
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