Just received an electro motor to build my own disc grinder – your comments please

S

Steinmann

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Jan 12, 2010
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Hi everybody. Pls find attached some pictures; I was told that this engine is from a broken pump from an ice-cream factory (?) and is in top order (and for free:D). I will thank you all if you can give me some advice:
1. Is it possible to run it with a variable frequency?
2. Will it be good for a disc sander?
3. What will the best way be to build/attaché the work rest?
4. Any other comment or idea?
Thanks a lot – Michael.
Engine001.jpg

Engine002.jpg

Engine005.jpg

Engine006.jpg

Engine007.jpg
 
Do you know if it is single phase or 2 phase. Big question as a lot of industry motors are 2 phase and will not run on home electricity which is single phase. If not on the motor then take it to a motor shop.
 
pixelhack said:
This is not a DC motor so no variable frequency drive for this.
Click to expand...

So you're saying DC motors use VFD's ???
Wrong.

DC motors use DC controllers
3 phase AC Phase motors use VFD Variable frequency drive.




Steinmann
Since You're in Israel, the metric designations will confuse most users here.
I'm in Canada - officially metric, but we still use HP rather than KW
2.2kw = 3 HP

It is a 3470rpm motor, twice the speed of a 1700 rpm motor.
I would likely use this on a belt grinder than a disc.


That may be bigger than you need for a disc & the VFD's i have seen
have $ based upon capacity - and they seem to take a $ jump when they get over 2hp



I don't find any info on that motor that I can read.
It looks to be 220v
the question I would look for is whether ir is single phase power, or 3 phase power.

single phase no VFD, three phase VFD is possible


I don't see a starting capacitor, so it is possible it is 3 phase.


See if you can find your motor in their catalogue and ID the specs.
http://www.electricmotorsmt.com/eng/index.htm
http://www.electricmotorsmt.com/pdf/gen-mot.pdf



Take the cover off the wire connection terminal box and see if there is a diagram there.
 
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Most disc have a 5/8" shaft requirement. You'll want to mic yours to see what size it is.

Good luck, Fred
 
pixelhack said:
This is not a DC motor so no variable frequency drive for this.
Click to expand...

VFD's are specifically made for AC motors (AC = alternating current or cycling of polarity based on a frequency, DC = 0 hz no frequency)
DC's use a variable resistor/rheostat, that is why before solid state devices DC was used for speed control, easy to implement

the OP's motor is a 3 phase motor that can be wired wye or delta
you should be able to run this with a properly selected VFD
 
depending on how you wire it internally (it can be changed) both for voltage and coil configuration (wye or delta)
it can be powered by these voltage(s):
50 hz
380-420 wye
220-240 delta
60 hz
440-480 wye
250-280 delta

a VFD can do phase conversion (1 to 3) and voltage conversion, say 220/1 input to 480/3 out
the drive must be sized for the amps per input leg if going 1 to 3 phase, basically 1.73 (sqrt(3)) times the load amps
then calculate KW rating
if you run this in 50 hz / 240-1 in / 240-3 out
the motor at full load will draw 8.1 A at 2.2 KW (VA = 8.1 x 240 x 1.73 ~ 3360 VA, eff or eff/pf ~ 2200/3360 ~ 65%
drive should be 1.73 x 8.1 x 220 ~ 3.1 kVA ~ kW or next larger size ~4 HP

this is becasue the output will distribute power over 3 wires/phases at 8.1 A each
the inoput will only have 2, so will carry more for the same power
i = 3360 / 220 ~ 15.3 A (~ 1.73 x 8.1 ~ 14)
 
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12345678910 said:
So you're saying DC motors use VFD's ???
Wrong.

DC motors use DC controllers
3 phase AC Phase motors use VFD Variable frequency drive.
Click to expand...

Sorry, got it mixed up with some PWM stuff I do. At the risk of being wrong yet again...looks like 3 phase motor to me. :)
 
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actually most VFD's use PWM from an SCR inverter/switch to make the AC
input AC/60 hz/fixed voltage
converted to DC (rectfied)
then the DC bus is PWM'ed by electronics to make an output that varies in freq and magnitude

PWM can also be used for position control of a DC motor (linear or rotary)
 
Shrodinger's Cat said:
actually most VFD's use PWM from an SCR inverter/switch to make the AC
input AC/60 hz/fixed voltage
converted to DC (rectfied)
then the DC bus is PWM'ed by electronics to make an output that varies in freq and magnitude

PWM can also be used for position control of a DC motor (linear or rotary)
Click to expand...

Thats cool. Thanks for the info and sorry to take this thread off topic. (I have been messing around with some low voltage DC PWM for goofing around with small motors.)
 
To use a wye/delta motor on a VFD you have to hook it up as "across the line on the delta run connections".

Connections used are determined by for the voltage output of the VFD.

If this is Greek to you ( or Hebrew to others) get someone who understands these words to show you the six wires needed for connection.

What you need to know:
Your voltage at your shop - 220VAC 50Hz single phase (most likely).This will also be the VFD input voltage.
The VFD output voltage - It will need to be 220/240 VAC 3Ph for this motor.

What you want to know:
The six wires and how to connect them for across the line delta run.
 
Thank you all for replying; most things where indeed Greek to me (or Hebrew to others :)). Anyway, it was a pleasure to read all the replays and learn a bit more, see other points of view even when it came a bit out of the main issue.
I do have a 3 phase supply at my home and I can phone the guy who delivered me the engine, he will know all regarding the electricity, so I don’t expect many problems from this side.
Main difficulties I can see are the technical ones, regarding of where to purchase the 9” disc(s?) or how to make them, and how to approach the rest / table thingy, as I want it to be strong, flat of course and with a hinge-out-of-the-way system, in order to change discs rapidly and comfortably. I could not find lots of info regarding this issue, and most self made disc sander where crafted from timber, which is out of the question for me (I do metal, not wood).
I thank you all – Michael.
 
Looks like 3 phase industrial to me, to big for what you want anyway, not worth the trouble, get a 1/2 hp one at yard sale for $3 like i did, and your table trouble is simple, your over thinking it, don't move table at all, it gets old tear it off and fish a new one on..stood for many days in front of one at aircraft repair station, learned to hate that machine, better now though..
 
Unfortunately we do not have these yards as in EU or USA...
I don't have any other choice - it has to be built for long lasting as I don't have any other machine and it is far too fast and strong for a belt grinder, that also needs much more space, belts are expensive and is more difficult to build.
 
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