out of ideas

[fruecrue]

Well I wish you could have done that yesterday, would have saved me some typing.

For the record this was a signal phase squirrel cage motor correct?

poke.......poke......

"SIGNAL" phase.....

poke.......poke......

typos are funny!

[Airmechanical]

3 phase!!! still may have some typing to do on this one.

it's the same for single phase!

as stated, i have tested that before as well, but just not today

i am all for having beers and testing motors, or just having beers, and Crown and Seven's



.

[tipsrfine]

I tested it today "again"

my job today was going behind Testing and balance, and follow there advice

the Test and Balance company had me replace a 2 hp motor with a 3 hp motor and a 7 inch drive pulley (which was bigger than stock) in order to attain the proper CFM

i wired the motor before i mounted it because of it's location, then i thought about some of yall

i fired up the motor without a pulley or anything on it

FLA was 9 amps at 230 volts and 4.5 amps at 460 volts, my supply voltage was 230

the motor drew 4.8 amps "unloaded"

once i installed the non adjustable pulley, it drew 13 amps, as you know Test and Balance never gets this right the first time

that's why i purchased an adjustable shiv while i was at the supply house the first time

to finish the story, i installed the adjustable shiv opened up the shiv to attain an amp draw of 9.3 amps

there was a 1.15 service factor so i called it done



.

I'm sure somebody somewhere is going to post something that explains why somehow your test was somewhat skewed. Theory is good for that.

[Airmechanical]

I'm sure somebody somewhere is going to post something that explains why somehow your test was somewhat skewed. Theory is good for that.

i have said many times here on HVAC-TALK;

book smarts and theories are one thing

"real world" problems and solutions are another



.

[ACFIXR]

Fruecru- try replacing the batteries in your DMS and re check your voltages again.(1 cent)
Maybe all the motors got dropped?(1 cent)
=0

[DeltaT]

All this is starting to crack me up! You would think we were in the ARP section!

Airmechanical. Don't forget that Fasco, not me, Fasco says it takes at least 2 hours for the motor, I assume unloaded or loaded or overloaded, to reach it's whatever heat.

Anyway, I hope all you guys have a great and safe New Year. Be safe out there cause we will have to continue this next year!

[little john]

has the frequency/hz of the incoming power been checked?

[Airmechanical]

Fasco says it takes at least 2 hours for the motor, I assume unloaded or loaded or overloaded, to reach it's whatever heat.

maybe a private message to CHRIS WORTHINGTON from the controls committee would be in order;

a private message with your above quote

then he can come back on here and tell us more specifically what he really meant or thought

it's sad that after he made his controversial post he just ignored us

i sort of can't blame him, when i have been wrong on this website, it is a bit embarassing

but we all make mistakes, admit them and move on

you will gain a ton of respect that way "CHRIS"

this particular overheating without a load issue has been fun for me

simply because "i have" tested these things before

it was especially fun yesterday testing and coming up with the same conclusion

you can twist reality, but you can't change it



.

[tipsrfine]

I'm just glad Airmechanical did the test and posted it. I'm still learning even some of the basic stuff on here and it is frustrating as a learner when there is a thread that has such opposite information. Opinions are fine, but that posting links to stuff and then speaking as an expert on the subject while really just talkin out your ass pisses me off.

[Pneuma]

I'm just glad Airmechanical did the test and posted it. I'm still learning even some of the basic stuff on here and it is frustrating as a learner when there is a thread that has such opposite information. Opinions are fine, but that posting links to stuff and then speaking as an expert on the subject while really just talkin out your ass pisses me off.

Several people have posted links, so it's not clear who you are insulting with your comment and from my perspective, insults aren't going to make this a better thread. Just read around the chest pounding...and don't add to the noise, which now I am also. Anyway lots of good things have come out in this thread and it's not done yet, grab a beer and watch!

[tipsrfine]

Several people have posted links, so it's not clear who you are insulting with your comment and from my perspective, insults aren't going to make this a better thread. Just read around the chest pounding...and don't add to the noise, which now I am also. Anyway lots of good things have come out in this thread and it's not done yet, grab a beer and watch!

You're right about the good things about this thread. I came away knowing more about motors than I did before. It's almost scarry how much information you have to try and absorb about almost anything before you can even begin to say you know something about it. I know enough to know how much is left that I don't know.

I still wish Fruecrue would have mentioned if he knew if that pool motor had anything more specific in common with the blower motor-like a junction box or anything. If those failures are related and the only thing they have in common is the same panel then it just has to have something to do with that new light system they put in. I don't know, but I do know there's a lot I don't know about a lot.

[DeltaT]

Drats.....I really wanted to take a vacation from this post for a while at least. Not saying anything is wrong or there has not been a lot of information going around, but it seems like it just goes on and on.

Anyway, getting back to real field experiences of my own. Over the years I have installed or repaired motors that have flipped their belts and have run for who knows how long and all of them have been very, very hot to the touch.

Present time example, took on a building that has 9 air handlers with belt driven blower motors from 1/2 to 3/4 HP. Had a history of no maintenace. One of the blower belts broke so the motor had been running 24/7 for who knows how long...months, I'm sure.

Touched the motor and burn my hand. Had to wear glove to remove it so I could replace it because I no longer trusted that it was a good to go motor. I don't remember if it has a internal thermal overload or not. I know that the one I replaced it with did on purpose.

So I'm just saying that electrical motors of our residential/light commercial types do get very, very hot to the point of damage when they just sit there and run without any load.

The true experinment for this, if someone is willing to do it, is to mount a motor in a resonable temperature...68 or above...and just let the thing run while chart recording the shell temperature over a week or so and display the results.

[ACFIXR]

A panel schedule would be good information..........also

[plainjs]

What do we KNOW

We know we see similar characteristics (high amp draw) from multiple motors from multiple manufacturers.

We know that this situation did not exist on a previous occassion. (I seem to recall this from an early post but I'm not going back through all posts to check)
We know the wiring is correct.
We know the Voltage is apparently OK.


Given the above and the fact we have an enormous DC load attatched to same panel, I'd be leaning towards a latent electrical issue.
Either the effect of lighting system, which could be eliminated by opening breakers feeding those circuits, hell shut down every other circuit while you are at it, leaving only breaker(s) that power(s)your equipment.

If this does not change your findings, I'd bring in a little 230v generator, hardwire the motor to it and check again, my bet is that you have an incoming power problem, I once lost ground on feed to my house and some really wierd things were happening, like Garbage disposal starting when I turned off the TV!

If this doesn't help I'll be at the bar......

..Newbie

[fruecrue]

Sounds very interesting. Can't wait to hear updates. The only thing I could add: is there any DC voltage going to the motor in addition to the expected AC? Perhaps some of the low voltage lighting has backfed or induced some sort of DC voltage that is screwing with the motor?? Just a thought. I worked on a reefer that had 24Vac and 10Vdc on the same line and it burnt out relay coils repeatedly before I discovered it. Let us know what you find.

In response to plainjs, thanks for your input. You are not the first nor only one with these suspicions. Unfortunately, I can't get back to test these theories just yet. I added in the original post that I had shed lighting, which was very vague. In fact, what I had done was shut down approx. half of the total lighting at a control point in the master suite. I did not disconnect power to the lighting panels as you suggest, and I did not measure for DC voltage as above quote recommends.

I have yet to bench test the motors(lots of opinions on this), which I believe will be informative as to whether I am dealing with motor or power supply issues.

whatever the outcome, I'll gladly join you at the bar. how long is the ride from Buffalo?

[Chris_Worthington]

maybe a private message to CHRIS WORTHINGTON from the controls committee would be in order;

a private message with your above quote

then he can come back on here and tell us more specifically what he really meant or thought

it's sad that after he made his controversial post he just ignored us

i sort of can't blame him, when i have been wrong on this website, it is a bit embarassing

but we all make mistakes, admit them and move on

you will gain a ton of respect that way "CHRIS"

this particular overheating without a load issue has been fun for me

simply because "i have" tested these things before

it was especially fun yesterday testing and coming up with the same conclusion

you can twist reality, but you can't change it



.

Is what I said and still say as backed up by the various manufactures links and others, is that a motor dependent upon its construction can overheat while unloaded and once it is overheated, it can over amp at that point.

Real world,,,,,, replacing a 1/8th HP condenser fan motor with a 5HP condenser fan motor,,,, will be toast in a short period of time.

I have been watching this thread and believe that "all" has realized that there is more to a motor then amps and volts alone, there is the design of the motor with its power factors, break horse powers, service factors, etc, etc. That on occasion need to be considered when having issues on a newly installed/problematic system.

I also stated that on a newly installed/problematic system that sometimes the only thing that can truly help you diagnosis and repair the system is to know and understand the total design of the system. The "system" meaning all of it, the dampers, the coils, the duct work, etc.

My point, you need know more then amps and volts. A static reading and someone locating the specs on this unit, would have helped us to diagnosis this/ rule out design.

My problem with this thread and in the real world, is how often the design, the instructions, is ignored. I get several phone calls daily from techs stating that they have done this or that, replaced blah blah blah and now it does not work? when I ask if they have read the instructions and checked the other pieces to the puzzle, the answer is almost always no?

When I ask them to check "all" the pieces to the puzzle, read the instructions and to call me back "if" they have any more problems, I seldom get the return phone call, crazy eh?

[tipsrfine]

That on occasion need to be considered when having issues on a newly installed/problematic system.

I think this is what caused most of the debate-you saying that this was one of those occasions.

[kdocsr05]

what I said and still say as backed up by the various manufactures links and others, is that a motor dependent upon its construction can overheat while unloaded and once it is overheated, it can over amp at that point.

Well said Chris, design conditions that is the key

[tipsrfine]

what I said and still say as backed up by the various manufactures links and others, is that a motor dependent upon its construction can overheat while unloaded and once it is overheated, it can over amp at that point.

Well said Chris, design conditions that is the key

I agree with this based on general knowledge and from the latest information I've read-never disagreed. The only motor I've ever heard that can burn out pretty quick is a fuel pump in a car, since apparently they are cooled by the fuel.

But no fan or blower motor in the world is going to overheat and overamp in just a few minutes of running without a load. This is why design conditions and all that other science behind motors does not apply in fruecrues situation. Offering that knowledge to him as if it will resolve his issue at hand is just not helpfull, in fact it reflects pretty poorly on one's understanding of that science in the first place.

[Some Dude]

That is correct block off either the supply or return it doesnt matter. Fan motors are designed to do work, if they are not loaded they will not build sufficient speed to cool themselves.
Ever take a blower out of a replacement furnace and try and run it?
Sometimes they will overheat etc, block off the supply they build speed and drop amperage and run fine.

Hello?