Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-03-2013, 08:11 PM   #1
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Share |
Default

ELectric motor issue


Seems to be THE week for electric motor problems...

The motor is a GE 7-1/2 hp triclad ball bearing, 184T enclosed unit that is installed in a scroll for a Dustkop dust collector unit installed 33 years ago!
The motor has performed perfectly fine for all these years untill one day
back in February when it was very cold outside and the unit is outside fully exposed to the weather.

With the collector running the motor was starting to make an ear splitting screeching sound, but then it stopped.
The rotor in the motor turns as freely as you'd ever want, so I pumped in some grease and figured in the better weather I'd look at removing it for replacing the bearings unless it died before.

Well the other day it was reported to me that it was making an odd noise, which of course stopped before I could go and listen. I turned it back on and MAYBE I think I hear a little bit of a harshness, not grinding or squeeling, but a sound that doesn't sound right.
The rotor turns just as freely as can be, so I took the back cover off and I could see the rear bearing, and it's sealed, turns just fine and seems tight to it's raceway with no slop.
I could move the rotor up and down a bit and it definitely felt like it could move enough the front bearing is the problem.

I tried to find an exploded diagram for this motor to get a better idea of it's specific construction so as to determine better what else might need to be replaced, but was unsuccessfull and there's none in the paperwork.


Motor with the rear cover removed:




Ive had to replace plenty of such bearings before, but this motor is on a stand 12 feet in the air and having a direct connected fan on the shaft inside the scroll means having to use a puller which we don't have.
It also can't be a case of sliding the fan and rotor out the scroll since the motor's rear fan is aluminum and pressed on, needing a special puller as well.

This is a little different style motor than I've taken apart before, and it seems GE doesn't make this motor any more so I don't want to risk breakage or damage trying to remove either fan with the wrong tools or borrowed puller.
So it looks like I'm going to have to remove 12-15 screws on one side of the scroll, that many on the other side, the 6 motor mounting bolts and the conduit to pull the motor with the fan and one scroll cover plate on it out as an assembly, and take it to a local bearing shop and let them replace the bearings.

The bearings are the only thing I can think of that would cause the noises, and the front bearing seeming to have play in it that I feel is too much suggests one of it's balls has been ground down to power or something.

Usually you get a hard to turn or frozen bearing, but that's not the case here, the rotor turns so freely you get the impression blowing on that fan will move it.

__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
Old 06-04-2013, 12:22 AM   #2
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

ELectric motor issue


Best bet is take it to the moteur shop and they will change the bearing on that size of the moteur it is brezze for them due they will have proper tools to swap it around.

I know you mention scroll collector and you say front bearing is shot well ya got it right there due the thrust from the scroll will ride on the bearing on sideway.

There are some bearing they will have speical thrust bearing appaction which from time to time it will show up like that kind of useage.

But with orignal bearing you have in there which it last very long time seems it did do the job pretty good.

Once you get the new bearings in the place. there is one serious warning I will pass it to you .,,

SVP mark all the conductors so when you put it back together it will run in correct rotation. Ya know the scroll units do not like to run backward so just be aware with that.

also if you have ampmeter with ya check the running current on them after you put it back together to make sure it is not drawing over the limit of the nameplate of the moteur.

Merci,
Marc

__________________
The answer will be based on NEC ( National Electrical code ) or CEC ( Cananda Electrical code ) or ECF ( Electrique Code France )
frenchelectrican is offline   Reply With Quote
The Following User Says Thank You to frenchelectrican For This Useful Post:
RWolff (06-04-2013)
Old 06-04-2013, 01:31 AM   #3
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
I know you mention scroll collector and you say front bearing is shot well ya got it right there due the thrust from the scroll will ride on the bearing on sideway.

There are some bearing they will have speical thrust bearing appaction which from time to time it will show up like that kind of useage.

But with orignal bearing you have in there which it last very long time seems it did do the job pretty good.
The front bearing is the only one that makes sense since the rear bearing appears to be fine, but as we know- such things can fool you when they are cold v/s when they heat up.
The rear bearing seems fine "cold" but who knows how it is after the motor has run for 20, 30 or 40 minutes and the bearing heats up.
I'm the kind that as long as the motor is apart I would replace ALL the bearings even if one looks fine, it's better to spend the $5 or $10 for the bearing than have to tear into the thing again later!

That is my plan, take it out and let the motor shop remove the fans from the shaft and put the new bearings on, as you say, they would have the right tools and everything else.

I've only run into one bearing once that I could not remove because it was an unusual design, and I had the whole thing taken to the shop and they had the proper tools to remove it and put the new one in.

Oh yes, for sure I will mark the wires.

The unit looks very close to this one, the scroll can be seen but this looks to be a belt driven model, ours is a direct drive, no belt but more work to remove the motor:




I would say 33 years is a good life for a motor like this, I know in the last 15 years I have had to do absolutely nothing to the motor other than pack grease in twice a year.
__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
Old 06-04-2013, 10:12 AM   #4
Member
 
Join Date: Jun 2007
Posts: 3,503
Default

ELectric motor issue


Just replacing bearings is not advisable unless you have the ability to check all the bearing tolerances.
You also may not have the ability to balance the rotor.
Since you greased a sealed bearing, it sounds like the zirk fittings are still on it?

Remove the zirk fittings and put plugs in each hole so it does not happen again.
Measure the inner and out race along with the end bells for the correct tolerance provided by the bearing manufacturer.

If you are not sure how to to this, then take this motor to a motor shop like Marc suggested.
They do know how and will give you a report on all the issues this motor may or not have.
This motor is very old and fortunate for you, its on a standard frame.
So replacing the motor will be very easy and probably much less money than a motor shop bill.
Let the motor shop quote you new and repair.
J. V. is offline   Reply With Quote
Old 06-04-2013, 10:38 AM   #5
Electrical Contractor
 
jbfan's Avatar
 
Join Date: Jun 2004
Location: Newnan GA
Posts: 5,682
Default

ELectric motor issue


Replace the motor and send that off to a shop.
What happens if that thing seizes up?
Production come to a stand still?
__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"
jbfan is online now   Reply With Quote
Old 06-04-2013, 08:35 PM   #6
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by J. V. View Post
Just replacing bearings is not advisable unless you have the ability to check all the bearing tolerances.
You also may not have the ability to balance the rotor.
Since you greased a sealed bearing, it sounds like the zirk fittings are still on it?
The motor has no zirk fittings, it came equipped with slotted grease plugs, 2 on on the back and one with a hose on the front bearing, the manual for it outlines a greasing schedule chart based on duty, it has "severe duty" calling for grease every 3 months, our use is not severe but fits the criteria for the chart's annual grease schedule. Generally I give it a small pump of grease annually.
The actual instructions say to remove the slotted plugs, screw in a flexible grease gun hose into one, and put just enough in to see it come out the other open hole, remove the hose and replace the two screws.
The front bearing is inaccessable due to the scroll housing configuration, so there has always been a single flexible grease hose with a brass cap on it for that permanently in place. I don't know who put thta in or when, but it was longer ago than 16 years as it's been that way all the time Ive been there.

For that one I have to remove the hose off the grease gun and screw the gun onto that hose.

It was a surprise to see the sealed bearing on the rear, because there are greasing plugs there and the directions for the motor say to grease it there.

Only thing I can come up with is there is a thrust washer that is not visible in the photo, between the bearing and the housing, the grease seemed to accumulate there, so I have to assume that unless years ago someone replaced open greaseable bearings with the wrong sealed type, that the greasing is not for the bearings per sei but for the thrust bearing and end of the shaft.
It's lasted 33 years and I've maintained it for the last 16 so it would seem all has been good.
I really doubt anyone has replaced the bearings before, and no one remembers it having been worked on before.

I don't have any specs to go by for clearances on this motor, we do have a machine shop with slide calipers, dial calipers, 2 milling machines but nothing for balancing a rotor.

Quote:
Measure the inner and out race along with the end bells for the correct tolerance provided by the bearing manufacturer.

If you are not sure how to to this, then take this motor to a motor shop like Marc suggested.
Yeah, I pretty must had decided right off that because of the fact we don't have the correct pullers to remove either fan off this, that I'm going to have to pull the motor out of the scroll WITH the fan and the inner panel of the scroll and let the foreman haul it to the place where he gets bearings and electrical supplies, I don't know exactly what the place is, maybe a "bearings incorporated" shop, machine shop, I don't know, but they can do what is needed.


Quote:
They do know how and will give you a report on all the issues this motor may or not have.
This motor is very old and fortunate for you, its on a standard frame.
So replacing the motor will be very easy and probably much less money than a motor shop bill.
Let the motor shop quote you new and repair.
I am hoping the front bearing IS the issue, it could in fact be just one, there could be a thrust bearing that is shot or something else, and I don't know how available parts would be for a motor this old. Bearings should be easy but other internal parts could be a bear to find replacements for, in which case a new motor is probably better.

I believe I will be yanking the motor out within the next couple of weeks when the system is not needed while most of the crew is overseas for a month. Soon as my foreman gives the go ahead I'll post some pics and results, might be 2-3 weeks from now.
__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
Old 06-04-2013, 08:55 PM   #7
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by jbfan View Post
Replace the motor and send that off to a shop.
What happens if that thing seizes up?
Production come to a stand still?
If it was up to me that would be what I'd do, but yeah this is how it goes:

if it starts making noise, the workers using it will just keep right on using it, usually *I'LL* find out about a problem when one of them comes by my desk and tells me that a machine is not working right or making noise, of course when I go to take a look it's either SEIZED UP, smoke coming out, totally dead, or making enough noise to raise the dead.

Natually I ask why they didn't turn the machine OFF when they FIRST noticed the problem, and come got me then?

I've never gotten a satisfactory answer to that one yet in 16 years!
So yeah, what will probably happen is someone will use it for a personal project over the weekend, KEEP using it even though it's beating itself to death and screaming bloody murder at 100 db, finish their project, close up and go home, and then Monday morning when I come in to work, someone will after a while mention that the ___insert machine name here____ isn't working... and when I go to look it's totally dead and seized up.

I know one Monday I learned the steel tube extension for the table saw had been cut in half! this was 1/8" thick 1"x1" steel 5' long, no one knew how it got cut, no one fessed up, it had to have been sparking like the 4th of July on a wood cutting saw blade and making a huge amount of noise, but the one responsible didn't notice or STOP and back off what he was cutting??

That's how it usually goes down and I've come to expect that, no sweat, I get paid the same and I don't mind working on machinery and motors at all, but we DO have a number of unique and old machines that you just cant get parts for and when someone just lets a defect go till it seizes up, they make it ten times worse due to the additional damage.

We have a South Bend lathe used for special parts making occasionally, it actually has a stamp on the bottom that it was made for the war department, 1942, I've had to rebuild that. We have another machine made by ELU in Germany, long defunct company, parts not available, I've had to rebuild that several times and make do with creative repairs to keep it running.
Usually it's a minor part replacement involved, but with over 50 shop machines not including the roof HVAC units, and each having an electric motor, many having belts, there's always some bearing or belt that needs replacement, and usually that's about all that's needed.

But a year ago someone was using the Powermatic planer and one of the cast iron pressure bar fingers broke off the bar (later I found it had an old crack in it in a thin area) and it did extensive damage in there, about $2800 worth of damage to the bar, bed, knives, putfeed rollers, the main cutter shaft, springs and more.
They located used but good parts for the castings that were damaged, found a solid pressure bar, bought new bearings, springs, and I spent a couple of days rebuilding the machine.
Events like that are rare though.

You get the gold star if you correctly identify this machine I also have to maintain:

__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/


Last edited by RWolff; 06-04-2013 at 09:02 PM.
RWolff is offline   Reply With Quote
Old 06-05-2013, 10:35 AM   #8
Member
 
Join Date: Jun 2007
Posts: 3,503
Default

ELectric motor issue


I seriously doubt you would find a thrust bearing on a 7.5 HP motor. Especially if its mounted horizontally.
Large vertical pump motors are usually equipped with thrust bearings. You might have a roller bearing in lieu of a ball bearing?

Why is there sealed bearings if you have the ability to grease the bearings?
Seems someone has been into this motor besides you.
You cannot grease a sealed bearing and greasing one does nothing and can even cause a problem.

The specs come from the bearing shop or manufacturer.
All bearings have tolerances to follow. Its a plus or minus type deal and any decent bearing supply house can provide this information to you.

You might be refering to "Bearings and Drives"?

They have no ability to help. Only to sell parts, bearings and motors.
Everyone needs a good motor shop to count on for things like this.

Look around your plant and see what types of motors they use. You can then Google this motor manufacturer and ultimately find an authorized service center in your area.
These are the people you want to check the motor out.
This is what they do.
J. V. is offline   Reply With Quote
The Following User Says Thank You to J. V. For This Useful Post:
frenchelectrican (06-05-2013)
Old 06-05-2013, 10:51 AM   #9
Electrical Contractor
 
jbfan's Avatar
 
Join Date: Jun 2004
Location: Newnan GA
Posts: 5,682
Default

ELectric motor issue


Is that the first ever air compressor built?
__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"
jbfan is online now   Reply With Quote
Old 06-05-2013, 12:38 PM   #10
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by jbfan View Post
Is that the first ever air compressor built?

Getting warmer, but it's not an air compressor! give up?
__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
Old 06-05-2013, 12:55 PM   #11
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

ELectric motor issue


Quote:
Originally Posted by RWolff View Post
Getting warmer, but it's not an air compressor! give up?
Vaccum pump

Merci,
Marc
__________________
The answer will be based on NEC ( National Electrical code ) or CEC ( Cananda Electrical code ) or ECF ( Electrique Code France )
frenchelectrican is offline   Reply With Quote
The Following User Says Thank You to frenchelectrican For This Useful Post:
RWolff (06-05-2013)
Old 06-05-2013, 01:00 PM   #12
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by J. V. View Post
I seriously doubt you would find a thrust bearing on a 7.5 HP motor. Especially if its mounted horizontally.
Large vertical pump motors are usually equipped with thrust bearings. You might have a roller bearing in lieu of a ball bearing?
I'm not sure, but I think this unit is designed to be used in any orientation, it just happens to be in the horizontal configuration, but I seem to remember the paperwork indicated it could have been installed vertically too.

Quote:
Why is there sealed bearings if you have the ability to grease the bearings?
Seems someone has been into this motor besides you.
You cannot grease a sealed bearing and greasing one does nothing and can even cause a problem.
Yeah this is a mystery, because as you cited- you can't grease sealed bearings, but there is a large flat washer I'm calling a thrust washer- on the end of the shaft between that bearing and the back housing, the grease goes into that area. I don't know about the front as I haven't gotten into it yet, but a flexi grease hose was installed there due to the tight quarters.


Quote:
The specs come from the bearing shop or manufacturer.
All bearings have tolerances to follow. Its a plus or minus type deal and any decent bearing supply house can provide this information to you.
Yep, this is true, though I am going by the assumption these are the original bearings, they may in fact not be, and furthermore- with the grease plugs and flexi hose for greasing bearings originally, and these bearings being sealed type does suggest they aren't original.
A lot can happen over 33 years but no one remembers the motor having been overhauled or worked on before, they do remember the entire unit being relocated 3 times, and being expanded once for additional capacity by adding a secondary booster below the floor on the main line.

Quote:
You might be refering to "Bearings and Drives"?
I was thinking of http://www.bearingsinc.net/

But I'm not sure exactly what shop the foreman has used over the years to get bearings and have one set of bearings on a German machine replaced by them at their shop as it had a number of clips and things needing special tools to remove.
I'll have to remember to ask what place, it's in a larger town 20 miles from here.


Quote:
They have no ability to help. Only to sell parts, bearings and motors.
Everyone needs a good motor shop to count on for things like this.
For sure, and we DO have some oddball machines made in Germany, SCMI, ELU, an Italian made Balestrini mortising machine, power feeds and a drill press made by Delta, and another Italian company, sliding table saws by Altendorf in Germany etc., but we also have some Powermatic, Jet, Timesaver and others.
Before I started there they used to ship out hand tools - drills, jigsaws etc that needed repairs to the "tool hospital" which was ridiculous- paying for UPS to ship a Milwaukee 3/8" drill that cost $99 according to the paperwork- bought new 20 years ago to a place to fix, pay their fee and return shipping!
Trouble with that is, you start replacing worn out parts where do you stop, you cant JUST replace one worn gear and put a new one on the gear train with the worn others, and expect it to run right, so you wind up replacing this part and that one, the bearings, and something else, and before you know it you have $75 in parts alone, and maybe a couple of hours shop time to repair a drill that you can buy new for $125-$150.
__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
Old 06-05-2013, 01:00 PM   #13
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

ELectric motor issue


Quote:
Originally Posted by J. V. View Post
I seriously doubt you would find a thrust bearing on a 7.5 HP motor. Especially if its mounted horizontally.
Large vertical pump motors are usually equipped with thrust bearings. You might have a roller bearing in lieu of a ball bearing?

Why is there sealed bearings if you have the ability to grease the bearings?
Seems someone has been into this motor besides you.
You cannot grease a sealed bearing and greasing one does nothing and can even cause a problem.

The specs come from the bearing shop or manufacturer.
All bearings have tolerances to follow. Its a plus or minus type deal and any decent bearing supply house can provide this information to you.

You might be refering to "Bearings and Drives"?

They have no ability to help. Only to sell parts, bearings and motors.
Everyone needs a good motor shop to count on for things like this.

Look around your plant and see what types of motors they use. You can then Google this motor manufacturer and ultimately find an authorized service center in your area.
These are the people you want to check the motor out.
This is what they do.
J.V. did make a good point reguarding of the type of bearing it can be used and sometime they will use wrong type of bearing espcally if not aware of high trust load.

That why I always read the moteur nameplate some time it will mention bearing size but it will not say ball or roller bearing type due the size of both useally the same but methold of bearing construction is differnt for both types.

I useally go with ball bearing much as possible espcally with thrusted loads.

Rwolff., check the scroll section if they did have timkin bearing on them if not some case someone did replace with wrong type as well ( that something you should check when it is apart. )

Merci,
Marc
__________________
The answer will be based on NEC ( National Electrical code ) or CEC ( Cananda Electrical code ) or ECF ( Electrique Code France )
frenchelectrican is offline   Reply With Quote
The Following User Says Thank You to frenchelectrican For This Useful Post:
RWolff (06-05-2013)
Old 06-05-2013, 07:11 PM   #14
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by frenchelectrican View Post
J.V. did make a good point reguarding of the type of bearing it can be used and sometime they will use wrong type of bearing espcally if not aware of high trust load.


I useally go with ball bearing much as possible espcally with thrusted loads.

Rwolff., check the scroll section if they did have timkin bearing on them if not some case someone did replace with wrong type as well ( that something you should check when it is apart. )

Merci,
Marc
He did, and I can't say with certainty what could have been done to the motor before my time, I asked the foreman again today and he doesn't know/remember any work done on it, but then he has been with the company only since 1988 and the unit predates his tenure.
Here are a couple of additional photos, one showing one of the 2 plugs on the rear the manual says to grease, the second photo shows the flexi grease hose that was added to grease the front bearing, installed before my time but clearly it was installed to grease the motor. For all I know the front bearing is not a sealed type, it could be totally different, the rear one definitely is a sealed bearing now.








The other side:

__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/


Last edited by RWolff; 06-05-2013 at 07:13 PM.
RWolff is offline   Reply With Quote
Old 06-05-2013, 07:23 PM   #15
Architectural Sculptor
 
RWolff's Avatar
 
Join Date: Jan 2013
Location: USA, Midwest
Posts: 765
Default

ELectric motor issue


Quote:
Originally Posted by frenchelectrican View Post
Vaccum pump

Merci,
Marc

Bravo! you get the gold star tonight, it is indeed a vacuum pump! like the other it has a GE motor.
This is an oldie, it came from the local hospital about 25 years ago where it was originally used to provide vacuum for the operating room.
I t has babbet bearings and a metered oil drip system that allows periodic drops of oil to fall thru a couple of glass sight tubes into small metal tubes going to the bearings.
The new mercury tilt switch was the only servicing it's needed in the last 16 years. It has no name, brand or any identifying information at all on it anywhere
It still draws to the 15" the tilt switch is set for, we use it for a very large vacuum table, it doesn't see a whole lot of use but when it's used it will be run all day without shutting off due to the size of the table and porosity, leaks etc.
No one knows it's age, I would guess it probably dates to around 1940 or earlier.




__________________
Sculpture scholarship recipient, 2008
Asbestos information: http://www.diychatroom.com/f98/asbes...pt-1-a-181840/

RWolff is offline   Reply With Quote
The Following User Says Thank You to RWolff For This Useful Post:
frenchelectrican (06-05-2013)
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installing an electric water heater in series with boiler paul01420 Plumbing 10 04-20-2013 08:48 PM
90 amp electric car charger! The future... Billy_Bob Electrical 16 02-16-2010 02:01 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.