Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1
Default Does this VIDEO depict a bad 3 phase motor?


I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.

The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?

thanks
  #2   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,384
Default Does this VIDEO depict a bad 3 phase motor?

Ignoramus26205 wrote:


I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.

The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?

HUH? What is WRONG with the guy? The water is BARELY moving at ALL!
I'm not sure the sound in a YouTube video is good enough to tell much,
but it didn't sound wrong. If he wants a super-balanced motor, he's going
to have to go to a Fanuc spindle motor or something.

One doesn't expect a 10 Hp motor to "purr like a kitten". Also, if he's
using a rotary phase converter or something like that, even though his L-L
voltage is well balanced, the motor may have slightly more vibration than
with a real 3-phase mains supply.

Jon
  #3   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 2,013
Default Does this VIDEO depict a bad 3 phase motor?

He has it mounted on a hard / semi-rigidity / wood pallet.
He should have it on shocks like an isolated rubber sheet
without bolts through making the thing hard again.

Rubber washers top/bottom with metal washers to transfer bolt
head and nut to keep within bounds but not hold tight. Let the
motor float in the bounds.

If the need is so tight, then he should go multi-phase and super
balanced with super bearings. The winding's have to be matched.

Martin

On 11/20/2017 8:32 PM, Ignoramus26205 wrote:
I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.

The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?

thanks

  #4   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 10,399
Default Does this VIDEO depict a bad 3 phase motor?

On Mon, 20 Nov 2017 20:32:29 -0600, Ignoramus26205
wrote:


I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.

The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?

thanks


Yes. It seems to have at least one bad bearing in it and at least one
of the internal balancing weights ,( or more) has come up missing (if
its not the type balanced by drilling away metal..

That is a decent quality motor. First thing Id do..is remove the rear
endbell and roll it 90', reassemble, run..check for out of balance,
roll another 90' etc etc..and see if one position makes it run
smoother.

Id also pull the stator and see if something is stuck in the
stator..something that got the balance off. If it was rewound..they
may..may have managed to get something jammed into the stator and its
causing it to be out of balance. Its also possible that they broke
something and its now out of balance.

Ive seen rewind shops really **** up a simple rebuild job..which is
why Im very...very careful about who I take motors to.

Gunner

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

  #5   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 10,399
Default Does this VIDEO depict a bad 3 phase motor?

On Mon, 20 Nov 2017 21:06:38 -0600, Jon Elson
wrote:

Ignoramus26205 wrote:


I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.

The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?

HUH? What is WRONG with the guy? The water is BARELY moving at ALL!
I'm not sure the sound in a YouTube video is good enough to tell much,
but it didn't sound wrong. If he wants a super-balanced motor, he's going
to have to go to a Fanuc spindle motor or something.

One doesn't expect a 10 Hp motor to "purr like a kitten". Also, if he's
using a rotary phase converter or something like that, even though his L-L
voltage is well balanced, the motor may have slightly more vibration than
with a real 3-phase mains supply.

Jon


Most motors "today"...will barely generate any harmonic rings. While
that is an older motor..its less than 20 yrs old..so it should be far
quieter and smoother than that one.

If the guy needs a super balanced motor...Wegg is quite good as are
most Baldors, these days.

That motor wouldnt pass for use on any CNC spindle in any machine I
service. It would be ok on a chucker or DV69 or manual
lathe..but..shrug...its pretty rough. Particularly for a 1725 rpm
motor.

Now I agree..if he is running it off a homemade rotary phase
converter...its possibly an electrical issue..but my gut
feeling..based on 20+ yrs of working with 3ph motors...its "not right"
by any means.

Gunner

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus



  #6   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 9,025
Default Does this VIDEO depict a bad 3 phase motor?

On Mon, 20 Nov 2017 20:32:29 -0600, Ignoramus26205
wrote:


I sold a supposedly rebuilt 3 phase 10 hp motor to a customer.


So you're wondering if it's an Al Special rebuilt (blow off and
repaint sans masking) or an actual rebuild?


The customer contacted me and is claiming that the motor is
defective, citing vibration and noise.

I asked him to make a video.

As a proof of this, he produced the following video:

https://www.youtube.com/watch?v=mn6bnva0Q0g

As I watched it, and looking at the water in cup, I could not but feel
that it is a totally normal motor. However, as I would like to be sure
of whether I am right, or wrong, I wanted to ask your opinion.

Does the above motor sound bad and does it vibrate excessively?


A 10hp motor with three or four tenths of vibration? Get out.
That big guy is purring.

There's a little something in the sound that bothers me on a minor
level, but I'd want a stethoscope to verify that it's from one of the
motor bearings and nothing else in the room. Just a harshness.
I wonder if a screwdriver held against the bearing housing and up
against the phone would pick anything up.

--
Shake off all the fears of servile prejudices, under which weak minds
are servilely crouched. Fix reason firmly in her seat, and call on her
tribunal for every fact, every opinion. Question with boldness even the
existence of a God; because, if there be one, he must more approve of
the homage of reason than that of blindfolded fear.
-- Thomas Jefferson
  #7   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,768
Default Does this VIDEO depict a bad 3 phase motor?

Iggy, I'm no motor expert, but that one seems a little noisier than any of
the 3 phase motors I am running. Mine are all running on variable frequency
drives though so the power delivery is very consistent. Some of the
equipment some of my motors is connected to makes some noise, but when the
drive belts are off they are pretty quiet.



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
It can depict the accused lift and correspond it in general its sphere. Rabbi M. S. Coughlan, MLA Home Repair 0 December 10th 07 12:51 AM
3-phase used for 1-phase (split-phase) power SRK Home Repair 9 July 22nd 06 12:01 PM
Electric Motor query - 3 phase /single phase [email protected] UK diy 5 May 6th 05 01:31 PM
Convert 3 phase Wadkin with single phase motor? oddjobboy Woodworking 15 October 15th 04 11:10 PM
5 hp 3 phase motor to a 3/4 hp single phase..? Paul Metalworking 33 March 23rd 04 08:23 PM


All times are GMT +1. The time now is 10:45 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"