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Motor nameplate voltage bedlam.

Motor nameplate voltage bedlam.

Motor nameplate voltage bedlam.

(OP)
Here's one for serendipity, as we were talking in another thread about 120V 3Ø.

A guy called me yesterday to help him get and install a VFD to run a motor. I asked him to shoot me a picture of the motor nameplate. Check the voltages on it..





120V 3Ø??

But wait! Look at the only wires it has:
Not sure what to make of this.. besides three un-rewireable power wires and two temp sensor wires.



Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor nameplate voltage bedlam.

I read that as 120 watts 3 phase 220 volts.

The CE marking is forged. I can tell by looking at it.

I know where that motor was built, even without looking at it.

RE: Motor nameplate voltage bedlam.

(OP)
OMG! I think you've cracked the mystery. I thought that was a 'V' but it may be a "W".
I was conjuring up all sorts of weird alternatives.

And yes the motors is a POS. It mounts vertically and has no thrust capability.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor nameplate voltage bedlam.

At 3 ph, 220 V, 1 A, shouldn't it be around 380 W? The pf and efficiency are that bad?

Muthu
www.edison.co.in

RE: Motor nameplate voltage bedlam.

Those speeds are either a mistake or a whole lot of slip. The high slip probably explains the low efficiency.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Motor nameplate voltage bedlam.

Isn't 1550 rip'ems a common speed for (single phase) shaded pole motors?

RE: Motor nameplate voltage bedlam.

This is a three phase induction motor. Normal speed for these is 1740 to 1760. That's 40 to 60 RPM slip.
This is showing 250 RPM slip.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Motor nameplate voltage bedlam.

(OP)
Oh wow! That speed was not ringing any bells for me. That's it, horrid slip. Guy said 'they' came with a VFD that is impossible to work with and wants me to change it to something usable. All I know is that, "it ran a bunch of inter-digitated PTFE disks sliding across each other". That could explain the slip.

Now he wants to turn a paddle in water. I'll go visit the thing and maybe condemn it all for a niece little Ebay geared drive motor. I doubt dealing with that motor and adding some likely needed gear reduction would not be worth the bother.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor nameplate voltage bedlam.

That motor together with that 20:1 gear box on the end of it can he had for $133... can't be very good quality.

Quote:

Place of Origin:
Shanghai, China (Mainland)

Brand Name:
VTV

Model Number:
Y90-120/90JB20G15

Output Power:
120w

Type:
Induction Motor

Frequency:
50/60Hz

Phase:
Three-phase

Certification:
CE

Protect Feature:
Drip-proof

AC Voltage:
208-230 / 240 V

Efficiency:
IE 1

outer dia:
90mm

speed ratio:
1:20

shaft dia:
15mm

start qorque:
1250 mN.m

rated speed:
1300/1550 rpm
I'm assuming the 1550RPM at 60hz is the motor speed, not the shaft speed at the end of the gearbox, but with the poor wording it's hard to tell.

Also, what is "start gorque"?






" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: Motor nameplate voltage bedlam.

Quote (jraef)

what is "start gorque"
It's what three-phale inductou motors produce, of course.

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

RE: Motor nameplate voltage bedlam.

As to efficiency - don't expect much from an IE1 motor. It can't get worse - there is no IE0 class. Still a lot better than an incandescent lamp..

There's another problem with the IE1, motors below 750 W (and above 375 kW) are not part of the IEx system. Our antipodes, no not Oz, have to learn how to correctly fake the CE mark And also how to use the IEx marking.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Motor nameplate voltage bedlam.

(OP)
Dang Jeff! I just got back to report in. Once there low-and-behold the output shaft is offset from the motor center line so obviously a gear box. Hence the wacko speed difference - not crazy-slip after all.

That said, how does a 1:25~1:180 ratio get one from 1800rpm down to only 1550rpm? Wouldn't this infer 10 to 72 rpm? Ah if you follow down the gear box info it seems to be 75RPM output.

Great, the guy wants 200RPM.. sigh. I'm not going to try to spin that cheap bugger 4,000 rpm.

Thanks a bunch Jeff. I was hung up on name plate speed which would be the output speed around here. Guess not in China.




Oh, and Jeff I found that motor for about $82.
Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor nameplate voltage bedlam.

(OP)
LOL Gunnar! You should write ad copy for them.

--Out moter is better efficint at make turn than light bulb.--



Keith Cress
kcress - http://www.flaminsystems.com

RE: Motor nameplate voltage bedlam.

You started my day in an excellent mood, Smoked.

I think your text is a lot better than mine could ever be. At least when it comes to the entertainment factor.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Motor nameplate voltage bedlam.

The nameplate shown in the photo is the nameplate of the motor. There is a separate nameplate for the gearbox.

And for such a small motor in IE1 1300/1550 1/min is fully reasonable. Look up a text book for "scaling laws" of electrical machines.

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