# 480v motor keep tripping the overloads



## Jerrydogg (May 23, 2011)

What do I look for?


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## All-Circuits (May 31, 2011)

Jerrydogg said:


> What do I look for?


 Larger heaters, sounds like the motor is going bad.


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## Hamer (Oct 5, 2010)

Not knowing what this motor actually does makes it a little complicated to answer, but my first instinct says either a) the mechanism the motor dirves is bound up or b) if it has a gearbox/speed reducer, it is bound up or low on oil.

Knowing the setup would help.


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## Zog (Apr 15, 2009)

All-Circuits said:


> Larger heaters, sounds like the motor is going bad.


Sure, whos needs a coordinated system anyways?:laughing:


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## Zog (Apr 15, 2009)

Jerrydogg said:


> What do I look for?


First step, take current readings on each phase. Find out if you actually have an overload condition.


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## Big John (May 23, 2010)

All-Circuits said:


> Larger heaters, sounds like the motor is going bad.


 :blink: You keep upsizing the overloads and if the motor wasn't going bad, it will be soon.

OP, assuming the motor actually is overloaded, what is it driving?

-John


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## All-Circuits (May 31, 2011)

zog said:


> sure, whos needs a coordinated system anyways?:laughing:


 one size larger


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## wil335 (Feb 15, 2011)

Zog said:


> First step, take current readings on each phase. Find out if you actually have an overload condition.


In addition, make sure the overloads are sized/adjusted correctly for the full load current of the motor. After your initial current readings for each phase, if possible, disconnect the load (coupling/belt/etc.) and take another current reading. You can determine if it's the motor or the load that's bad.


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## K2500 (Mar 21, 2009)

A long shot but summer is kicking in. Barring other problems, under or properly sized overloads may trip prematurely if subject to high ambient temperatures. Especially if motor is operated at full load.

Have any changes been made to the driven load?


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## lefleuron (May 22, 2010)

Buddy,

the overloads are there to protect the motor. These trip out because of high current causing extra heat- that same heat is cooking the inside of said motor.

All the general causes for an OL tripping have been mentioned. Now its your job to find out which of these is making the motor work extra hard.

As far as putting in larger heaters, this is one of the dumbest things I have ever seen a supposed "electrician" do. If you do that, you might just as well uncouple that motor right now and throw it in the trash- and save the waiting.

Overloads are sized to protect a motor, up-sizing the overloads is just a way for guys who couldn't troubleshoot a two piece extension cord to get by for a little longer.


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## All-Circuits (May 31, 2011)

lefleuron said:


> Buddy,
> 
> the overloads are there to protect the motor. These trip out because of high current causing extra heat- that same heat is cooking the inside of said motor.
> 
> ...


 Ok Buddy, senerio for you. say a motor has been in operation for years. The bearings start going bad or the insulation starts breaking down due to the motor being fully loaded which is appropriate of motor operation. The owner of the building or floor manager calls because the heaters are tripping. You check everything, FLC is in range and everything seems normal except the tripping heaters. the manager says this motor can't be taken out of service and they don't just have a spare lying around. Tell me how you keep the motor in operation till you get a new motor replacement. Now I have done what I suggested a couple of times only as a last ditch effort to keep the operation going for the customer. I know the heaters protect the motor, very well aware of this. But motors are not always necessarily protected to the maximum current rating. In both of my cases the motor overloads were undersized and gave me the right to upsize the heaters. Nothing against code or manufacturers guidelines were performed. Those motors lasted another 3-5 years without any problem. Now I don't recommend just any electrician taking these measures unless they know what they are doing, but I've been around the block a few times and don't take unnecessary risks with motors or any other aspect of my job. I have never been sued, or caused a fire. I have a perfect track record. So, without getting all angry and touting you know better, what would you have done that would have cost the factory owner less, and still get yourself called back year after year for any need of his?


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## BBQ (Nov 16, 2010)

All-Circuits said:


> Ok Buddy, senerio for you. say a motor has been in operation for years. The bearings start going bad or the insulation starts breaking down due to the motor being fully loaded which is appropriate of motor operation. The owner of the building or floor manager calls because the heaters are tripping. You check everything, FLC is in range and everything seems normal except the tripping heaters. the manager says this motor can't be taken out of service and they don't just have a spare lying around. Tell me how you keep the motor in operation till you get a new motor replacement. Now I have done what I suggested a couple of times only as a last ditch effort to keep the operation going for the customer. I know the heaters protect the motor, very well aware of this. But motors are not always necessarily protected to the maximum current rating. In both of my cases the motor overloads were undersized and gave me the right to upsize the heaters. Nothing against code or manufacturers guidelines were performed. Those motors lasted another 3-5 years without any problem. Now I don't recommend just any electrician taking these measures unless they know what they are doing, but I've been around the block a few times and don't take unnecessary risks with motors or any other aspect of my job. I have never been sued, or caused a fire. I have a perfect track record. So, without getting all angry and touting you know better, what would you have done that would have cost the factory owner less, and still get yourself called back year after year for any need of his?


Wow that is a lot of words trying to justify putting a penny in the fuse box.


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## lefleuron (May 22, 2010)

BBQ said:


> Wow that is a lot of words trying to justify putting a penny in the fuse box.


 Nomination- Post of the day!:thumbup:


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## All-Circuits (May 31, 2011)

BBQ said:


> Wow that is a lot of words trying to justify putting a penny in the fuse box.


 I choose to be thorough in my explainations


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## Jsmit319 (Sep 23, 2010)

Can't say much more than everyone else. You do need to check your amperage draws and see what you are getting. most of the time, it's something on the mechanical side binding up. I've seen everything from simple dirt build-up to seized gears and chain drives cause this. Of course, make sure you have all phases,,,,a 3-phase motor will try to run on a 3-phase delta system missing a phase.


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## Wirenuting (Sep 12, 2010)

Like everyone has said, your o/l's can be sized no larger then the motors FLA. 
There are different classes of o/l's but these only allow a longer time delay before they trip. A motor can run for a short time at it's SF, but it will cook. 
If your motors are only lasting 3 years and all of the equipment is in good shape,, I would bet that the motor was replaced years ago with one that was undersized. 

If you get 10+ years out of a motor your doing average. We have motors here that have been running up to 25+ years. But they get proper maintenance.


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## mutabi (Jun 2, 2009)

I would not be recommending to someone with 1 post to their name, that they upsize the heater size to keep the motor running, when there are a hundred other things to check before even considering doing that. The main thing being, is the motor actually overloaded? Most of the time, it is. Mechanical things wear out, and I am betting something being driven is worn causing an extra load on the motor. 

Have I upsized heaters? Yep. After I found they were not sized correctly in the first place.


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## RIVETER (Sep 26, 2009)

Jerrydogg said:


> What do I look for?


The first thing that I would ask is how soon after starting does it trip out?


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## Zog (Apr 15, 2009)

All-Circuits said:


> one size larger


So you say put in larger overloads, then retract your statement saying you "mistyped it and you meant to say replace with a smaller overload to see if it trips", then (obviously after realizing how that makes no sense at all) edit your post to say one size larger.


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## wdestar (Jul 19, 2008)

There are several things to consider in this scenario...

1. Was the original motor ever replaced, and if it was - did you replace it with a motor of equal or greater value Service Factor?

2. Was the machine manufactured outside the U.S.? - If it was, was the intention that the motor would run at 50 Hertz as opposed to 60?

3. Has the ambient temperature changed in EITHER the motor environment or the protection environment? Did an AC unit quit or has it been replaced in either?

4. Has the load changed? Did anyone ever check the original load (current draw) vs. what it is now?

5. Is there currently a phase or voltage inbalance that didn't exist before?

6. Does the tripping seem to occur only at certain times or when some seemingly unrelated machine is started?

7. ?

I could go on, but I've retired from that field.

Please send more info.


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## wdestar (Jul 19, 2008)

Oops. And egg on my face for not asking the obvious...

Is the machine genuinely being overloaded. If so, no protection devices will save this motor. IT'S DOOMED.


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## Jmohl (Apr 26, 2011)

A couple things to consider, One as other posters have suggested, is to take amperage readings on the motor. If all three phases are balanced and within nominal tolerances, then look at the o/ls, If they are thermal ie. Allan Bradley solder pots, they commonly degrade over time to where they no longer will hold the rated load. If they are magnetic, then look at the setting on them to make sure they are set correctly. Also worth looking at is transient conditions that may cause the trip, A bad sprocket on a chain drive system for instance, may hang occasionally causing a current spike.


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## Mike in Canada (Jun 27, 2010)

I dealt with a motor just yesterday that was sporadically popping the overloads. On that one the contactor had a dirty contact on line 2, so the motor was sporadically single-phasing. Watch for the intermittent stuff - it's a bugger.


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## mrmike (Dec 10, 2010)

it is obvious that you have high current as the motor keeps tripping on O/L. First, make sure you have the correct FLA. heaters.
What nobody has mentioned is MEGGARING the motor ! This will eliminate it & point to a mechanical load problem. You unhook the motor leads at the O/L block & meggar Phase to Phase to make sure you don't have one open (Infinity) Next , you meggar Phase to ground to check the insulation of the motor. It should be 1 Megohm or more..........
If you don't have access to a meggar or don't know how to use on- you can use your multimeter on resistance and get an idea..........
Sometimes even a "wet" motor will do this. You are actually meggaring the motor leads & motor- and if it shows bad-you have to unhook the motor anyway- so you meggar or resistance check with Multimeter, it there again when you have the leads apart to verify it is the motor or the leads.................


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## John Valdes (May 17, 2007)

All-Circuits said:


> Ok Buddy, senerio for you. say a motor has been in operation for years. The bearings start going bad or the insulation starts breaking down due to the motor being fully loaded which is appropriate of motor operation. The owner of the building or floor manager calls because the heaters are tripping. You check everything, FLC is in range and everything seems normal except the tripping heaters. the manager says this motor can't be taken out of service and they don't just have a spare lying around. Tell me how you keep the motor in operation till you get a new motor replacement. Now I have done what I suggested a couple of times only as a last ditch effort to keep the operation going for the customer. I know the heaters protect the motor, very well aware of this. But motors are not always necessarily protected to the maximum current rating. *In both of my cases the motor overloads were undersized and gave me the right to up size the heaters.* Nothing against code or manufacturers guidelines were performed. Those motors lasted another 3-5 years without any problem. Now I don't recommend just any electrician taking these measures unless they know what they are doing, but I've been around the block a few times and don't take unnecessary risks with motors or any other aspect of my job. I have never been sued, or caused a fire. I have a perfect track record. So, without getting all angry and touting you know better, what would you have done that would have cost the factory owner less, and still get yourself called back year after year for any need of his?


So you replaced undersized heaters with the correct size heaters, right? That is how it's supposed to be done.



All-Circuits said:


> I choose to be thorough in my explainations


Then most people will not read them. Rarely do I read a post as long as yours. 

Now the motor. Lets make sure we all know what a heater is, and what an OLR is. I take it that everyone understands the terminology.

Heaters do go bad. Once they have tripped and cooled many times the heaters has lost its ability to release the trigger at the correct current. So even the right heaters could be bad and should be replaced.

Very few facilities have the right equipment to test a motor. A megger is great and so is a meter for fractional sizes. A decent electrician can get an idea of the problem and can correct many of them on his own. But unfortunately, at some time or another a motor shop must be consulted.
They have the equipment and know how to diagnose and repair motors. I know of no contractors that own their own surge tester.

As said above, mechanical issues are usually the cause of overloading. Check this before you start doing anything.


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## AlokinT73 (Jun 4, 2011)

I'm new here but I'm going to give it shot. If I found my o/l is tripping, i would separate the load side and start the motor by itself and if the motor runs smoothly without strange noise coming from the motor and all phases of the motor are balance using the clamp meter, your motor should be okay. On initial start you should get high amp and it should settle to little or no current once it's running because you have no load. With that I will start looking at the mechanical side of the system (pump might be binding). On the other hand, if your o/l tripped right away without load, you may have bad motor. I suggest megger the motor to make sure there is no short or grounded windings.


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## captkirk (Nov 21, 2007)

BBQ said:


> Wow that is a lot of words trying to justify putting a penny in the fuse box.


 totally agree. your not fixing anything your just buyin time


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## Big John (May 23, 2010)

We've been talking our asses off in this thread and the guy who posted it hasn't even been back! :furious:

-John


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## Hamer (Oct 5, 2010)

Must not have been _that _critical then.

I think the general concensus is right. Most of the problems where I work end up being mechanical. But, because it has wires going to it, the first thing they do is call up the electrician on the radio. 

Most of the time it's a bad bearing or chain tension out of adjustment... something simple. I've had our overloads get worn out or cooked to the point they don't function, or a bad set of contacts, or God forbid the motor might actually be bad. But most of the time it's not an electrical problem. Do you seasoned vets see that too?

It is funny how this whole diagnosis and discussion started with "What do I look for?" and the OP hasn't checked back in. 

Hit n Run


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## Jlarson (Jun 28, 2009)

Put in bigger OL's :lol: 

Start with the basics. 

-Check voltages, confirm they are balanced, and you have all phases, check the VD across the starter too
-Check current
-megger the motor, and conductors going to the motor, if its a large motor get it surge tested by a motor shop
-Check the load the motor is hooked for issues that could cause the OL


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## Jmohl (Apr 26, 2011)

Hamer said:


> Must not have been _that _critical then.
> 
> I think the general concensus is right. Most of the problems where I work end up being mechanical. But, because it has wires going to it, the first thing they do is call up the electrician on the radio.
> 
> ...


Yup, mechanics in manufacturing facilities put the burden on us "sparkies" all the time... "hey electrician, the belt is slipping on my press fly-wheel, could you speed up the drive so it will work?"


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## brian john (Mar 11, 2007)

Are these thermal OL’s or electronic?

1. Verify amperage of the motor from nameplate.
2. Verify the size of the OL’s and that they are sized correctly, per the NEC and manufacture.
3. Has the ambient changed (temperature increased)?
4. Take amperage readings of motor, trending if possible.
5. Verify load requirements have not changed.
6. Perform FOP on OL’s.
7. is the motor operating at rated voltage?


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## brian john (Mar 11, 2007)

All-Circuits said:


> Larger heaters, sounds like the motor is going bad.


Why trouble shoot and solve the problem, when you can make a jack leg repair that could result in possible damage to the motor?
Randomly upsizing the OL’s is ...WELL, HARDLY PROFESSIONAL.


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## All-Circuits (May 31, 2011)

Well, I guess everyone gets their turn being the dumb son of a beach now and then. So much for my input into the debate. What I just want to know is what the heck the guy that posted the thread ended up doing. Until then I guess I will just have to keep enduring the attacks. Enjoy your drinks gentlemen, and good will to you all.


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## Jmohl (Apr 26, 2011)

AllCircuits, I didn't see any issue with your assessment, a little long winded but, hey.....That said, amp readings, meter checks for shorts, meg if you've got one, if it all checks out, O/Ls or contacts suspect. Not too much to read into it. Like you, I sometimes just gotta get the machine running to make production and if it takes out a motor down the line, cost of doing business....:whistling2:


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## Jerrydogg (May 23, 2011)

*O/Ls*

I'm here, I've been working nights. Thanks for all the help. Obviously this is a hot subject. The motor turned out to be badd, so we replaced it with a new one.:thumbup:


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## Big John (May 23, 2010)

Jerrydogg said:


> ...The motor turned out to be badd, so we replaced it with a new one.:thumbup:


 Good to hear the result. :thumbsup: How'd y'all end up finding it?

-John


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## Jmohl (Apr 26, 2011)

Glad it turned out ok for the OP. Thought occurred to me a little while ago, one thing to look at in the future, (assuming it is available,) is the design spec for the motor. A lot of times, when a motor goes bad, and the spec motor isn't available, a higher or lower sized motor gets put in. Not saying it's the right thing to do, but it is common for say a 3/4 hp motor to be subbed for a 1/2 hp. Often, the O/Ls and conductors aren't upsized accordingly.....


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## brian john (Mar 11, 2007)

Jmohl said:


> Glad it turned out ok for the OP. Thought occurred to me a little while ago, one thing to look at in the future, (assuming it is available,) is the design spec for the motor. A lot of times, when a motor goes bad, and the spec motor isn't available, a higher or lower sized motor gets put in. Not saying it's the right thing to do, but it is common for say a 3/4 hp motor to be subbed for a 1/2 hp. Often, the O/Ls and conductors aren't upsized accordingly.....


Sometimes? A lot of times. Often we see jobs were the building facility personnel replace the motor and go with what’s available.


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## MDShunk (Jan 7, 2007)

brian john said:


> Sometimes? A lot of times. Often we see jobs were the building facility personnel replace the motor and go with what’s available.


Ten four on that. I've done it myself. Here recently, I put a 3hp motor with an odd shaft, in place of a 5hp, on a hot water pump in an apartment building, knowing full well I was probably going to ruin the motor by the time the correct 5 horse came in. It lasted until the 5 came in the next day, but it smelled awful.


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## brian john (Mar 11, 2007)

MDShunk said:


> Ten four on that. I've done it myself. Here recently, I put a 3hp motor with an odd shaft, in place of a 5hp, on a hot water pump in an apartment building, knowing full well I was probably going to ruin the motor by the time the correct 5 horse came in. It lasted until the 5 came in the next day, but it smelled awful.


I (THINK?) in a temporary circumstance things are done, you should see some of the services we have built for blow ups. It is only temporary. Maybe I am a hypocrite but I see a difference in a temporary that is still as safe as possible for the conditions and making a permanent install and walking away.


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## MDShunk (Jan 7, 2007)

brian john said:


> I (THINK?) in a temporary circumstance things are done, you should see some of the services we have built for blow ups. It is only temporary. Maybe I am a hypocrite but I see a difference in a temporary that is still as safe as possible for the conditions and making a permanent install and walking away.


Right. I feel it's my duty to get things up and running any way I know how. Make it right tomorrow or next week. The trouble comes in when people do temporary things because they're too lazy to do it right or have no real intention to make it right... ever. Cabling out to a breaker on a tea cart, covered with a rubber blanket is a completely reasonable repair option until the right breaker gets shipped in, as one typical for instance. Doing a main tie with THHN strung in free air would be another.


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## BBQ (Nov 16, 2010)

MDShunk said:


> Right. *I feel it's my duty* to get things up and running any way I know how.


Come on admit it, you want to put lights and sirens on your truck. :laughing:

_'Here I come to save the day'_


:jester:


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## MDShunk (Jan 7, 2007)

BBQ said:


> Come on admit it, you want to put lights and sirens on your truck. :laughing:
> 
> _'Here I come to save the day'_
> 
> ...


I don't mind admitting that a draw a lot of energy from playing hero. A great deal of my sense of personal well-being is derived from saving the day. It's probably the #1 reason why I do this work. Doing things no one else cares to do, and often in a novel way that someone else might not have thought of, makes me happy with myself.


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## BBQ (Nov 16, 2010)

MDShunk said:


> I don't mind admitting that a draw a lot of energy from playing hero. A great deal of my sense of personal well-being is derived from saving the day.


OK ............ me too.


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## 10492 (Jan 4, 2010)

MDShunk said:


> A great deal of my sense of personal well-being is derived from saving the day.


Dude, that has egotistical written all over it.


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## Big John (May 23, 2010)

Dnkldorf said:


> Dude, that has egotistical written all over it.


 You either gotta push yourself to be good because you want to be the best in your mind, or push yourself because you want other folks to think you're the best, either way, it's gonna make you a little conceited.

Whether someone shows it or not is a different story.

-John


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## BBQ (Nov 16, 2010)

You guys have all missed the mark here.

The problem is tight bearings, you need to pump grease into the bearings to loosen them up.

I find one tube of grease per motor HP works great. :thumbsup:


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## MDShunk (Jan 7, 2007)

Awesome. :laughing:

I've seen guys destroy perfectly good bearings by overgreasing. It may seem trivial, but too much grease can overheat a bearing, and cause the grease to separate. The grease is essentially oil mixed with a waxy carrier. When it heats beyond spec, the oil runs out, and the waxy carrier is all that remains. Bearing destruction follows. 

There's the stupid factoid for the day.


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## Zog (Apr 15, 2009)

MDShunk said:


> Awesome. :laughing:
> 
> I've seen guys destroy perfectly good bearings by overgreasing. It may seem trivial, but too much grease can overheat a bearing, and cause the grease to separate. The grease is essentially oil mixed with a waxy carrier. When it heats beyond spec, the oil runs out, and the waxy carrier is all that remains. Bearing destruction follows.
> 
> There's the stupid factoid for the day.


Yep, same goes for bearing in circuit breakers. Mixing greases can lead to failure too, different greases use different compounds that can react with each other chemically and cause the grease to harden like a rock.


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## MDShunk (Jan 7, 2007)

Zog said:


> Yep, same goes for bearing in circuit breakers. Mixing greases can lead to failure too, different greases use different compounds that can react with each other chemically and cause the grease to harden like a rock.


I've seen that happen in older disco's that people re-greased the moving parts with God-knows-what. You could chip it off like hardened putty. The disco is trash when that happens, as far as I'm concerned.


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## BBQ (Nov 16, 2010)

MDShunk said:


> Awesome. :laughing:
> 
> I've seen guys destroy perfectly good bearings by overgreasing.


Never happens, don't you know the grease gets used up and just vanishes into thin air so you have to keep pumping more in ........



When I was a carny we had some special grease that was like sticky taffy, we used it for a few specific applications .... of course some guys thought it was to be used for anything ....... what a mess.


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## MDShunk (Jan 7, 2007)

BBQ said:


> Never happens, don't you know the grease gets used up and just vanishes into thin air so you have to keep pumping more in ........
> 
> 
> 
> When I was a carny we had some special grease that was like sticky taffy, we used it for a few specific applications .... of course some guys thought it was to be used for anything ....... what a mess.


I wish there was "universal grease". 

Get in the maintenance storage area of any big manufacturing company, and it's astounding the amount of different greases, oils, and hydraulic fluids they need to stock. Far gone are the days where a guy could run around with the same grease gun all day and grease everything on a given production line. I don't even know how they keep track of what takes what type of grease.


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## Zog (Apr 15, 2009)

MDShunk said:


> I've seen that happen in older disco's that people re-greased the moving parts with God-knows-what. You could chip it off like hardened putty. The disco is trash when that happens, as far as I'm concerned.


Just needs to be rebuilt, in fact I have a pile of Siemens FSV breakers in here now that have this exact issue. Some moron squirted WD-40 or something in the mech.


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## Zog (Apr 15, 2009)

MDShunk said:


> I wish there was "universal grease".
> 
> Get in the maintenance storage area of any big manufacturing company, and it's astounding the amount of different greases, oils, and hydraulic fluids they need to stock. Far gone are the days where a guy could run around with the same grease gun all day and grease everything on a given production line. I don't even know how they keep track of what takes what type of grease.


We put stickers on the front of our rebuilt breakers that say "Lubricated with XXXXX"


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## MDShunk (Jan 7, 2007)

Zog said:


> Just needs to be rebuilt, in fact I have a pile of Siemens FSV breakers in here now that have this exact issue. Some moron squirted WD-40 or something in the mech.


Probably. 

By the way, I'm hunting an older GE Cat # 245A2006P1 ground current detector. Do you have one in your stock?


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## BBQ (Nov 16, 2010)

MDShunk said:


> By the way, I'm hunting an older GE Cat # 245A2006P1 ground current detector. Do you have one in your stock?


I think these guys have one


http://tonyhan55.blog.163.com/blog/static/41627766201141992842918/


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## brian john (Mar 11, 2007)

BBQ said:


> OK ............ me too.


 
Double that for me.

And beat this Bob.

http://local.yahoo.com/info-12435936-midatlantic-power-specialist-sterling


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## MDShunk (Jan 7, 2007)

brian john said:


> Double that for me.
> 
> And beat this Bob.
> 
> http://local.yahoo.com/info-12435936-midatlantic-power-specialist-sterling


Dude... c'mon. My wife's name is Rikki. Do you have something you want to tell me? :laughing:


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## oldtimer (Jun 10, 2010)

MDShunk said:


> I wish there was "universal grease".
> 
> Get in the maintenance storage area of any big manufacturing company, and it's astounding the amount of different greases, oils, and hydraulic fluids they need to stock. Far gone are the days where a guy could run around with the same grease gun all day and grease everything on a given production line. I don't even know how they keep track of what takes what type of grease.


When I worked at an open pit iron ore mine, they had a specific grease to lubricate the sticks of the P.and H. shovels. It looked like black tar.
I can't remember what the name of this product was.
B T W, these shovels were electric. 4160 volts power source.


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## Big John (May 23, 2010)

Zog said:


> ...Some moron squirted WD-40 or something in the mech.


 Someone was telling me a story about a genius who decided to try and fix a sticking 15kV air break switch by lubricating the contact points with 10W30 motor oil.

Apparently it totally solved the sticking problem, because they ended up replacing the switch. :thumbup:

-John


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## Zog (Apr 15, 2009)

MDShunk said:


> Probably.
> 
> By the way, I'm hunting an older GE Cat # 245A2006P1 ground current detector. Do you have one in your stock?


That is a clamp on meter? Don't think anyone would have that, ebay might be your best bet. I am not in the test equipment business. http://www.jostfewkes.com/Rainbow_Catalog/Section_6_RainbowCatalog.pdf


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## Wirenuting (Sep 12, 2010)

As this pictures shows, you turn the o/l's over and they never trip. 
But wait ,, this motor is rated at 3.1 amps and is pulling 3.0. 
But these o/l's are good for 4.4 - 4.9 amps.

So even Mr Worf gave me a funny look and said, WTF Batman,, when I told him.


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## RIVETER (Sep 26, 2009)

Jerrydogg said:


> What do I look for?


If the mechanical load that the motor is driving has not changed, here is what I would do. If possible, let everything cool down...shut off. Upon restarting the motor, check the amperage that it is drawing. Remembering that an overload acts totally different than a "circuit" short.... the overloads will take longer to trip. Typically, if the motor drags to a stop, the load is too large or a bearing in either the motor or the gearing is faulty.


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## PsiMan84 (Oct 29, 2010)

*Is it a solid state overload? if so don't forget the one thing people always seem to do is route incoming lines right next to it which causes it to create nuisance trips and it'll drive you insane!!!*


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## MDShunk (Jan 7, 2007)

Zog said:


> That is a clamp on meter? Don't think anyone would have that, ebay might be your best bet. I am not in the test equipment business. http://www.jostfewkes.com/Rainbow_Catalog/Section_6_RainbowCatalog.pdf


Quite often, they're hanging on the side of the ground fault monitor that they go with, so I just guessed that you might have had the odd one or two surplussed out and in your hands. Guess not. It was worth the ask.


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## Mike in Canada (Jun 27, 2010)

MDShunk said:


> Awesome. :laughing:
> 
> I've seen guys destroy perfectly good bearings by overgreasing. It may seem trivial, but too much grease can overheat a bearing, and cause the grease to separate. The grease is essentially oil mixed with a waxy carrier. When it heats beyond spec, the oil runs out, and the waxy carrier is all that remains. Bearing destruction follows.
> 
> There's the stupid factoid for the day.


 Here's another stupid factoid. Electric motor windings are incompatible with the EP additive in grease. This is why there are special "electric motor" greases that don't contain the EP additive.
I don't grease motors of less than 100HP. Yes, I'm a licensed millwright and greasing motors is one of the things that we're trained to do, but I've seen FAR more motors fail from improper greasing than from not being greased. Leave the motors alone and THEY WILL LAST LONGER!
Big motors I re-pack the bearings by hand. The flow-through method isn't reliable enough. The grease relief port gets plugged, and instead of the new grease going through the bearing and pushing the old grease out the port, instead the new grease goes into the windings.


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## Jlarson (Jun 28, 2009)

MDShunk said:


> I wish there was "universal grease".


:yes: me too

I routinely have to clean mixtures of multiple different greases out of motors and machines. I really dread that.


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## Zog (Apr 15, 2009)

MDShunk said:


> Quite often, they're hanging on the side of the ground fault monitor that they go with, so I just guessed that you might have had the odd one or two surplussed out and in your hands. Guess not. It was worth the ask.


I am sure we have had some come through but we don't sell them, I will PM you a guy who might have some.

Edit: Guess I can't PM you.


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## All-Circuits (May 31, 2011)

PsiMan84 said:


> *Is it a solid state overload? if so don't forget the one thing people always seem to do is route incoming lines right next to it which causes it to create nuisance trips and it'll drive you insane!!!*


 It clearly looks like thermal overloads to me.


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## Mike in Canada (Jun 27, 2010)

Jlarson said:


> :yes: me too
> 
> I routinely have to clean mixtures of multiple different greases out of motors and machines. I really dread that.


 Some combinations of greases will do horrible things. It's relatively rare to find that nowadays, since simple urea greases are not something you trip over every day. The urea greases where terrible for forming lumps when combined with common commodity greases, but they have been replaced with new and improved grease bases which have the all-time worst name - di-urea. No, really.
Anyway, the di-urea based greases are compatible with lithium and other common commodity greases, so today any tube of run-of-the-mill grease is very likely compatible with any other tube of run-of-the-mill grease.

I use a full synthetic as my everything-but-electric-motors grease.
I use electric motor grease for electric motors.


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## PsiMan84 (Oct 29, 2010)

All-Circuits said:


> It clearly looks like thermal overloads to me.


didnt see the picture since its thermal than disregard my comment.


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## AFOREMA1 (Nov 23, 2009)

Mike in Canada said:


> Some combinations of greases will do horrible things. It's relatively rare to find that nowadays, since simple urea greases are not something you trip over every day. The urea greases where terrible for forming lumps when combined with common commodity greases, but they have been replaced with new and improved grease bases which have the all-time worst name - di-urea. No, really.
> Anyway, the di-urea based greases are compatible with lithium and other common commodity greases, so today any tube tof run-of-the-mill grease is very likely compatible with any other tube of run-of-the-mill grease.
> 
> I use a full synthetic as my everything-but-electric-motors grease.
> I use electric motor grease for electric motors.


Funny I produce a lot of that di-urea grease on a daily basis. Must be my eating habits .I never use it on motors though.


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## electricalperson (Jan 11, 2008)

MDShunk said:


> I don't mind admitting that a draw a lot of energy from playing hero. A great deal of my sense of personal well-being is derived from saving the day. It's probably the #1 reason why I do this work. Doing things no one else cares to do, and often in a novel way that someone else might not have thought of, makes me happy with myself.


nothing wrong with that. feeling like you saved the day for someone is a great feeling and well deserved


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## electricalperson (Jan 11, 2008)

brian john said:


> Double that for me.
> 
> And beat this Bob.
> 
> http://local.yahoo.com/info-12435936-midatlantic-power-specialist-sterling


i love that review


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## lefleuron (May 22, 2010)

MDShunk said:


> I wish there was "universal grease".
> 
> Get in the maintenance storage area of any big manufacturing company, and it's astounding the amount of different greases, oils, and hydraulic fluids they need to stock. Far gone are the days where a guy could run around with the same grease gun all day and grease everything on a given production line. I don't even know how they keep track of what takes what type of grease.


 A ha ha hA!

I watched these guys, trying to figure this exact thing out. Some place (where only they know) is a special mark made with a Sharpie. 

Now, how they keep track of what all the different marks mean is another thing. But the answer is out there.


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## AFOREMA1 (Nov 23, 2009)

lefleuron said:


> A ha ha hA!
> 
> I watched these guys, trying to figure this exact thing out. Some place (where only they know) is a special mark made with a Sharpie.
> 
> Now, how they keep track of what all the different marks mean is another thing. But the answer is out there.


Most facilities us pm matrices that detail each motor location, noted issues , date current motor was installed, type, size ect extra , and all past maintenance and upcoming with all details such as brush changes and grease types.


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## Jmohl (Apr 26, 2011)

AFOREMA1 said:


> Most facilities us pm matrices that detail each motor location, noted issues , date current motor was installed, type, size ect extra , and all past maintenance and upcoming with all details such as brush changes and grease types.


I don't claim to have all the experience you have in different plants but based on the four so far I've worked in, only one had a PM system. Matix for PM? Hah!!! they wouldn't know PM if it smacked 'em in the head with a two by four.:laughing:


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## brian john (Mar 11, 2007)

PsiMan84 said:


> didnt see the picture since its thermal than disregard my comment.


 
Don't disregard it that was an important statement.


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## Jlarson (Jun 28, 2009)

Jmohl said:


> I don't claim to have all the experience you have in different plants but based on the four so far I've worked in, only one had a PM system. Matix for PM? Hah!!! they wouldn't know PM if it smacked 'em in the head with a two by four.


:laughing::laughing::laughing: 

I'm yet to see a PM system that _really_ worked.


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## AFOREMA1 (Nov 23, 2009)

Jlarson said:


> :laughing::laughing::laughing:
> 
> I'm yet to see a PM system that _really_ worked.


It all depends on who runs the program if you have a good pm coordinator working hand and hand with the maintenance crews or hired contractors and the paperwork is kept up it can work well. But that is the problem most places don't use it properly or never implement one and things go to crap. 

They fall into emergency breakdowns. Meaning until something fails they don't bother with it. This is poor facility management and costly. But it pays well so no complaints from me.


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## Big John (May 23, 2010)

Jlarson said:


> I'm yet to see a PM system that _really_ worked.


They wanted to do that when I started here. "Let's set up a program to megger the motors every year!" 

What the hell is a once a year megger gonna tell you a dirty, high humidity plant? :no:

-John


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## Jmohl (Apr 26, 2011)

Of the four plants I worked at, one had a good Pm system. Used Maintmizer CMMS, All maintainers were part of Maintenance dept, had a PM team, a scheduler, and used the CMMS extensively. Two, including the one I am at now, Utilize eMaint, but on a very limited scale. The mechanics are part of production, the elecs, millwright, and machinests are in maint. No real PM to speak of, yet they take PM time every other week. The other had no CMMS, and we were multi-trade in maint. dept. PM was non-existant.


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## Zog (Apr 15, 2009)

Jlarson said:


> :laughing::laughing::laughing:
> 
> I'm yet to see a PM system that _really_ worked.


Maybe your clients should use someone else then :laughing:

Seriously, I have seen plenty of successful PM programs that fiollow ANSI/NETA recommended maintnenece and testing intervals and procedures and test like it was the gospel.


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## Jlarson (Jun 28, 2009)

Zog said:


> Maybe your clients should use someone else then


:laughing::thumbup::laughing:

Mine work, our clients own attempts at it didn't, one spent so much coin on their own attempt they almost bankrupted themselves


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## sparky970 (Mar 19, 2008)

So I'm at a fuel terminal right now that is having the same problem. Motor tripped yesterday and they don't know why. I meggered the motor and t-leads, ran the pump(no load), 20hp, 480V, pulling 10A. FLA is 23.7A. They had the same issue about a year ago. A different contractor replaced the overloads back then. Voltage was 280V to ground on all phases. Now I'm waiting for a truck to show up to test again under load. I did find a couple connections that weren't real tight, but not sloppy loose.


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## Big John (May 23, 2010)

I would say that 90% of the time when I've run into a "bad motor" that's "tripping overloads for no reason" there is one or more significant mechanical failures in the driven load that are causing the motor to bog down and trip. For some reason, though, it always becomes the electrician's job to prove to the mechanic that they have a problem they need to fix.

-John


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## niteshift (Nov 21, 2007)

For some reason, though, it always becomes the electrician's job to prove to the mechanic that they have a problem they need to fix.

So true John. That happens everywhere I think. Plants I've worked in I do both, mach. shop and electrcian. Best/worst of both trades.


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## JRaef (Mar 23, 2009)

Big John said:


> I would say that 90% of the time when I've run into a "bad motor" that's "tripping overloads for no reason" there is one or more significant mechanical failures in the driven load that are causing the motor to bog down and trip. For some reason, though, it always becomes the electrician's job to prove to the mechanic that they have a problem they need to fix.
> 
> -John


I think it's because "electrician" rhymes with "magician" but "mechanic" rhymes with "d!6k", so they expect magic from us, but they expect d!6k from them.


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## JRaef (Mar 23, 2009)

sparky970 said:


> So I'm at a fuel terminal right now that is having the same problem. Motor tripped yesterday and they don't know why. I meggered the motor and t-leads, ran the pump(no load), 20hp, 480V, pulling 10A. FLA is 23.7A. They had the same issue about a year ago. A different contractor replaced the overloads back then. Voltage was 280V to ground on all phases. Now I'm waiting for a truck to show up to test again under load. I did find a couple connections that weren't real tight, but not sloppy loose.


As has been implied, you are chasing an electrical solution to what is likely a mechanical problem. The mechanical guys will have maybe checked the bearings, but what may have happened is that someone changed the FLOW in that pump system. In dynamic pump systems (ie centrifugal pumps and some axial pumps) flow = load so if you change the flow, you change the load and it changes at the CUBE of the change in flow. 

So if someone tweaked a valve somewhere to increase the flow by 10% for example, the load on the motor increases by 1.1 x 1.1 x 1.1, or 131%. If you had a motor that was maybe 20% over sized, which is very typical, but someone tweaked the flow by just 10%, the motor becomes 13% overloaded. Measure the running load current, if it's higher than expected, start asking questions about changes in the pump impeller, piping, valves, flow restricters etc. I know it's not your problem, but see my post above about being expected to be a magician.


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## bobelectric (Feb 24, 2007)

lefleuron said:


> Nomination- Post of the day!:thumbup:


 I agreeth.And hope charlie dies soon.


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## RIVETER (Sep 26, 2009)

Zog said:


> First step, take current readings on each phase. Find out if you actually have an overload condition.


Zog...I love you man, but if he is tripping properly sized overload heaters...he is overloaded. Could be bearings...lack of oil on a chain...or just a bad motor.


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## sparky970 (Mar 19, 2008)

Ran motor with load 16.7A. Contacts did look a little burned. Also, noticed this pump, and its sister pump only had size 1 starters, on 20hp motors. I suggested properly greasing the bearings and changing to size 2 starters. Didn't find any other issues.


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## ace24wright (Jul 10, 2012)

We have an SAP system that spits out PM work orders on a monthly basis, so the the system will fail only if we fail to do the work.


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## K2500 (Mar 21, 2009)

Did you check for voltage drop across starter when it was overloading?
I agree with the others, probably mechanical, could be the trucks, check valve, ect...

Also, this thread is a year old.


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## AFOREMA1 (Nov 23, 2009)

Big John said:


> They wanted to do that when I started here. "Let's set up a program to megger the motors every year!"
> 
> What the hell is a once a year megger gonna tell you a dirty, high humidity plant? :no:
> 
> -John


A good pm program involves more than meggering motors. It has to incorporate inspection and cleaning of all components and other things as well. The testing of a motor alone is not a PM system.


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## JRaef (Mar 23, 2009)

sparky970 said:


> Ran motor with load 16.7A. Contacts did look a little burned. Also, noticed this pump, and its sister pump only had size 1 starters, on 20hp motors. I suggested properly greasing the bearings and changing to size 2 starters. Didn't find any other issues.


Most likely if you are running 20hp motors on size one starters, you are heating up the contacts and that heat is transferring to the OLR heater elements. That will make them trip even though the current may not be above the rating of the OL.


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