What's new
What's new

Lima conversion 3 phase motor stopped working without warning.

john worden

Aluminum
Joined
Aug 4, 2013
Location
Iowa USA
The 3 phase motor on my Lima conversion stopped working suddenly today. It now makes an odd sound. It can be turned by hand.
Power to the motor is good and switches look clean and good.
I need guidance on how to disassemble the motor.
It powers my very old Lodge and Shipley lathe and stopped in the middle of a job.
It did not restart after being switched off briefly.
Any help appreciated. John

EDIT-- Lima Electric Motor
2 HP RPM 1200 3 phase
V 220-440 amps 6-3
type R1 frame 224
Serial # 0732
 
The 3 phase motor on my Lima conversion stopped working suddenly today. It now makes an odd sound. It can be turned by hand.
Power to the motor is good and switches look clean and good.
I need guidance on how to disassemble the motor.
It powers my very old Lodge and Shipley lathe and stopped in the middle of a job.
It not not restart after being switched off briefly.
Any help appreciated. John

"TRUE" 3-phase, Lima's being one that often had integral geared-heads, don't often DO that: eg: spin-free (bearings are still at least"OK") and still make a noise.

Possible a thermal cut-out has tripped. Few open ALL windings, could be the cause of a dropped-phase. Same again an external thermal or a contactor out of whack in the motor-starter box not carrying all legs properly. Or a fused disconnect or common-trip CB.

Unless they've had a winding go bad?

if so, that's a rewind/re-varnish situation. With the usual costs and turnaround-time. Age can cause that. RPC not. VFD can hammer older motors though.

What's the REST of your situation?

And - all-else being checked first - other than nostalgia, any reason not to just go find a new(er) motor?
 
Appears Lima used dedicated frame to suit their very nice four speed gear box - which was "A" Ford based - at least for some number of years

And other than nostalgia, any reason not to just go find a new(er) motor?
 
Appears Lima used dedicated frame to suit their very nice four speed gear box - which was "A" Ford based - at least for some number of years

Lima, Master, and Century competed in that space, "back in the day" small machine-tools - mills especially. ISTR Lima and Century merged? Or mayhap Master acquired one or both? Wasn't "recent", either way..

Master survives as part of ABB/Rockwell Automation/Baldor/Reliance/Dodge for long years but the only gearmotors no longer include those handy parallel-shaft // coaxial shaft multi-speeds.

Not long back, a 10EE was found to have a wonky contactor, mag starter - nothing expensive wrong atall.

Let's hope he just has a dropped Phase. Or two.

Rewinds of small motors, any type, are hard to justify, present fully-burdened rates.
 
Check for good clean connections? Multimeters dont take much power to show a reading, but under load the bad connection will cause excessive voltage drop. Use two light bulbs in series (230v) to load the circuit, then test the voltage? Heat may have built up in the bad connection when it was running, then the starting surge did it in?
 
Thanks for quick replies.
If a replacement could easily be fitted I would do it.
I feel that there is age related damage internally. I have replaced a gear in the gearbox and in the apron so I know the machine has a lot of hours on it.
I think we will remove the cover off the back of the motor tomorrow and inspect for visual damage.
Motor rebuilders aren't as common as they were at one time so I'll have to find one to inspect and probably rebuild it.

John
 
Thanks for quick replies.
If a replacement could easily be fitted I would do it.
I feel that there is age related damage internally. I have replaced a gear in the gearbox and in the apron so I know the machine has a lot of hours on it.
I think we will remove the cover off the back of the motor tomorrow and inspect for visual damage.
Motor rebuilders aren't as common as they were at one time so I'll have to find one to inspect and probably rebuild it.

John

BEFORE you "go there"... IF.. there had been no warning stink of magic smoke... I say again.. the same sort of symptom - dropped phase or phase(s) on a 10EE turned out to be right in the Motor Starter. Think contact wear. Swing-plate/spring-loaded arm/armature out of alignment, loose thermal overloads, fuse holders losing tension, yadda, yadda-cheap-and-fast-to-fix.
 
I talked to a motor rebuilder this morning and he suggested checking the breakers as some of you have stated.
He said their company compressor will do the same thing. Hum and no start 3 phase. Correct voltage but low amps. No visual indication that breakers are bad.
Buying new breakers today for installation Friday.

Meanwhile..... First thing this morning we pulled the back off the motor and windings and armature APPEAR to be ok.
The motor shaft is stepped for the armature and splined onto the trans. main shaft and can be pulled out of the trans. The armature must be removed from the shaft in the direction of the transmission.
Going into the trans. is not necessary. Don't ask how I know that.
The ball bearings and housings on both ends of the motor shaft look good and were well lubricated.

If anyone has questions about the inner workings of this setup now is the time to ask and I will answer to the best of my ability.

Thanks again. John Doing my best to keep America Great!
 
:D I hate being the old curmudgeon, but you are barking up the wrong tree. It was running - how can the motor be needful?

It makes odd noise instead of running = single phasing = switch gear issues, not motor issues

Nothing wrong with taking it apart - if you are needful of a look-see, but that won't make it run again

I talked to a motor rebuilder this morning and he suggested checking the breakers as some of you have stated.
He said their company compressor will do the same thing. Hum and no start 3 phase. Correct voltage but low amps. No visual indication that breakers are bad.
Buying new breakers today for installation Friday.

Meanwhile..... First thing this morning we pulled the back off the motor and windings and armature APPEAR to be ok.
The motor shaft is stepped for the armature and splined onto the trans. main shaft and can be pulled out of the trans. The armature must be removed from the shaft in the direction of the transmission.
Going into the trans. is not necessary. Don't ask how I know that.
The ball bearings and housings on both ends of the motor shaft look good and were well lubricated.

If anyone has questions about the inner workings of this setup now is the time to ask and I will answer to the best of my ability.

Thanks again. John Doing my best to keep America Great!
 
A motor rebuilder said to consider the breakers even if there is no visible sign of failure.
Friday while the motor is apart we will check the windings and 3 phase circuit.
If that examination doesn't raise any flags then I will probably fit new breakers.
Onward and upward. There is work to do building a new Hot Rod Roadster for a high school buddy.
John
 
A motor rebuilder said to consider the breakers even if there is no visible sign of failure.
..and the contacts and all related parts as position them on any relays or contactors. Also fuse clips and their attach, disconnect box contacts and attach, crimp terminations and, and...

It just SHOUTS "dropped phase" or phaseES. ONE left to lock the rotor at attempted start. As 3-P motors WILL reliably DO.

Period of ten years, '74 to '84, as the only "Engineer" in a brick and mortar retail chain, one of my crosses to bear was managing the contractors dealing with the effect of air-mass - not even right on us - thunderstorms popping ONE fuse of one leg, on all those daggone HVAC units on our 18 store's + central warehouse rooftops. Motors didn't often survive that abuse, either.

Fast-forward as to WHY I am such a strong proponent of modern higher-grade "Common Trip" circuit breakers and NOT a big fan of fuses, "independent legged" by their very nature.

No smoke nor stink from the motor? LAST place I'd be looking.

They CAN die without even a warning whimper, but it ain't their basic nature to go quietly into the dark.

3-Phase motors are straightforward critters akin to Wolverines. They fight back to survive, and damn the odds against 'em, win more often than not.
 
John - you keep mentioning BREAKERS. What is between the breaker and the motor?

What do you use to turn off and turn on the lathe?

If in between is a rotary switch or the more capable magnetic starter, therein is likely the problem
 
If the motor won't start and just hums, sounds like you have a single phase condition, that is one leg of the phases is open for what ever reason.. Broken wire, bad contact in the starter switch, breaker not delivering all three lines...I would check all three phases to ground going to the motor, starting at the power panel, fuse box, what ever you have powering the unit.. .. All three lines should have voltage to ground unless of course you are running straight 440 which I doubt.....Ramsay 1:)
 
My 3 phase machines run on a RPC. This includes my old 5 HP Champion compressor. Usually not a problem but a little drain on start up. After maybe 10 years of trouble free starting it did same thing. No start and loud hum. It was a fuse. All lines running off RPC are fused twice. Not an electrician but found the one fuse that differed with VM and deducted it to be the problem child. It was. Back in business ever since. Now my old P&W lathe with a Lima trans/motor drive stopped working and has the dreaded hum. I know I need to look at another fuse. The one that blew before are these little tiny fuses and I bought 10 for replacements. As a mechanical type person my mind jumps to the most complicated and expensive repairs possible. Almost always it is something simple and hopefully affordable to repair. Start simple and work your way into the worst case scenario. I too have been one to ask "how to" but still had to do my own "worse case thing". Like the "stove is hot syndrome" old habits are hard to break. One more vote for the "missing phase" solution. Good thread for those who have not had this happen before. Don't panic it can be an very easy fix. In my case the Electrical Eng who built my 20 hp RPC put an extra safety thing into the design and double fused my machines. I highly recommend those with fuses keep a couple of spares. My larger 30 amp cartridge fuses are not available at Tractor Supply and none of my friends run 3ph so when I burn one it is going to take some effort and time to get a replacement. Don't be that guy. I also do not know if in my case a RPC will have a tendency to blow fuses more often than clean 3 ph off the power pole? Seems to me the power was a little off on one leg while the other two were nice and even? Again I am not an electrician and might have things a little goofy on the RPC thing.

Regards, John.
 
If the motor won't start and just hums, sounds like you have a single phase condition, that is one leg of the phases is open for what ever reason.. Broken wire, bad contact in the starter switch, breaker not delivering all three lines...I would check all three phases to ground going to the motor, starting at the power panel, fuse box, what ever you have powering the unit.. .. All three lines should have voltage to ground unless of course you are running straight 440 which I doubt.....Ramsay 1:)

Bingo Ramsay1 ! My electrician determined that one leg of the windings is indeed down and out.
I delivered it to a motor shop late Friday and will hear the official verdict from them Monday after they inspect and test.
A rewind will run at least $500 but it would be the fastest and least expensive way to put the machine back to work.

While we are on the subject do you suppose there is a "slicker" gear lube than the standard 90 weight?
Just thinking that shifting the old model A gears might be easier with some modern lube.
Don't get me wrong the gear box works as intended but my operators sometimes get in a hurry and expect to change gears quickly.
The proper method I believe is to be sure the spindle is stopped dead and to giggle the gears a bit with the hand wheel which helps align the gears as the shift lever is worked.
Like I said earlier I have robbed a gear out of a Model A to replace a broken one. I'm quite certain my highly skilled but sometimes impatient Mikey moved the gear lever before the spindle had stopped.

So it goes. John
 
Glad to see that you found your problem... I know about having stators rewound as I have an early forties Cincinnati pedestal grinder that was running fine until I took it apart to change a noisy bearing.. I made the mistake of cleaning the windings with motor cleaner and that lead to a rewind of a very heavy and expensive motor...I should have just put some new sprayon insulation on the windings skipping the washing I think....

At my work, I sometimes had to troubleshoot well pumps with 150 hp vertical motors.. When the tower gauge showed lower than normal, I would first drive to the pump site and look at the fuses on the transformer bank... I would usually make that my starting point and the motor my last....Once we had a well motor not start due to a blackbird shorting the high tension terminal on one of the transformers which opened the corresponding high tension fuse.. A bird caused a single phase condition so no 440 three phase coming into the well house...

Always remember: Three phase motors will run on single phase but they will not start on single phase....They cannot stand single phase condition long if the rotor is not turning....Usually the overload relays will open if one of the phases is dead but not always....

On the oil, I don't know what would help with the stripping of the teeth.. That's why the handwheel is on the output end of the gearbox to aid in shifting....Cheers; Ramsay 1:)
 
While that motor is out for rewind (and $500 is the norm for rewinding ANY three phase motor, as it's the exact same labor and more trouble to do a 2hp as a 50hp, only difference being quantity of copper), go over all your contactors, fuses, etc... to find out WHY that winding burnt out. Could have just breathed its last, but I'm betting, as already mentioned above, you have a bad contactor or connection causing high current draw on that phase, which burned up the windings. Maybe not, but might save you another $500 rewind in the near future.
 
Thanks for all the suggestions.
Today the motor shop confirmed a dead leg. I gave the go ahead to rewind it.
Before I power it up I will have an electrician test the circuit.
John
 








 
Back
Top