5 hp motor help.

[Alex22Vb]

Hi,

My Name is Alex and I am haveing trouble with a 5 hp motor.
My problem is is that I can't seem to get it to run again.

(since it is probably best for you to see what I'am talking about here is a link that will take you directly to the webpage that I bought it from,

http://www.northerntool.com/webapp/...0&PHOTOS=on&TEST=Y&productId=461&categoryId=0

)

~sorry for the long address~

I had it running for about 15 min. total run time. ( I was testing it out, so it was turning on and off ) This 5 hp motor is going to be used to power a 22 in. set of fan blades for a SNOWMAKER, yes a machine that make snow.

( If you go sking then you'll probably notice that on the sides of the trails that there are Big oil shaped barrles with fans in the back, that is what I have built.) The reason that it needs to have such High Hp is because it has to be able to keep up it's RPM's when the static pressure Builds, From all of the water that it has to propel out about 60 or so ft.

Any way, back to my problem, This motor is suppose to draw a 22 amps @ 240 volts running and I think 28 amps @ 240 volts starting. I have it running off of a 40 amp @ 240 volt breaker though a 10 guage wire. I'am useing a 40 amp breaker because when I went to homedepot the guy told me that that I needed like 10% amps over what the starting amp was, (Which was going to be 35 amps, but he said that a 40 amp would due just fine.)

IS THIS TOO MUCH TO BE RUNNING??? Could this be why it just kicks and then blows the breaker???

I don't think that this is the problem because the motor what running fine for all of 15 min.

But it is possible that water may have got into the copper windings of the motor because It was pushing the water out at the time that it just stopped. Also the wires were not inside the panel in the back of the motor at the time, but they were covered up with caps and electrical tape. (Again it was being tested at the time, thats why the wires were out side of the panel)

Most likely some water (very little) must have got into the back windings. I say this because the motor can not be drawing more then 40 amps, it's just not possible because it's a 28 amp max ~start up~ motor. So in this case I think that it has got to be a dead short. In the motor.
I took the entire motor aprat to see if any thing was burn't or looked out of place and I did find that in the back copper windings, on the bottom half (were the "vent" is for cooling) that it look very dull and kind of like it had "sut" on it. Only when I when to rub it off, it did not come off. It was like a perminet discoloration of the copper wires. This is deffinitly were any water would come in if it were to enter in to the motor and it looks as though it did. So, if it is a short, What can I do to fix it??? Can it be fixed???

I don't think that the starting capasiter is bad simple because it turns for a split sec. (gives a little kick). But since it dos'ent stay running, maybe it could be the running capasiter??? Is it possible that the running capasiter is blown and that is why it is not staying on???

More then likely it's a short because it kicks the breaker every time.

So, it is eathier the running capasitter or it's a dead short. Which is it???
How could I fix it???

I have pics and I will try to post them if I can, I don't know if I can though, never used this forum before.

Thanks for all of your help,
Alex

 

[Laplacian]

Your motor is pulling more like 130-150 amps during start, not 38. I'm suprised it started once and ran 15 minutes.

You need to use a motor starter, not a circuit breaker. GE, Cutler-Hammer, Allen Bradley, etc. make fine equipment suited just for this purpose.

 

[Alex22Vb]

SO You don't think it is shorted out?

What about the starting capasiter on top the motor, isent that like a "motor starter"?

 

[SteveKW]

That motor has built in MANUAL overload already ... you don't need a starter.


You failed to mention how far the motor was from the breaker panel and how long the cord was?
Just a hunch...Once you tell us the length of that run, I am sure we will give you the reason for its failure!

 

[jraef]

Several things potentially wrong here.

Laplacian is incorrect about the current draw (that would be for a 3 phase motor, not a capacitor-start 1 phase), but he still brings up a good popint. There is no way that a 22A motor is going to pull only 28A on startup. It should be around 33A if it is a cap-start / cap-run type (your link doesn't say, but compressor motors usually are). You are probably reading something incorrectly.

10ga cord is probably too small for this load and definitely too small to be protected by a 40A breaker. 10ga is only rated for 30A max under the best of conditions, i.e. short distances and no conduit etc. Too small of wire will cause a voltage drop, which will cause your running current to increase, maybe even smoke your motor windings

If the windings didn't smoke, did you try just waiting for the overload to reset? That motor has a cheap little "kilxon" type overload switch imbedded in it. If it overloads, the switch opens up and prevents you from starting until it cools down. The description says it is a manual overload. Did you try resetting it?

If water did indeed get inside and short the windings, you are using the wrong type of motor. Again, that catalog link does not provide enough info, but I suspect that since they call it a compressor motor, it is just an Open design. You should get Open Drip Proof (ODP) at least, and maybe even TEFC (Totally Enclosed Fan Cooled) if you are using it outdoors in the snow!

It could also be that you have damaged the centrifugal switch so the start capacitors never switch in.

With all these issues I think you need to take it to a motor shop and get some bettter advice than what you got at Home Depot.

"Venditori de oleum-vipera non vigere excordis populi"

 

[skiier]

You and the fan blade on your snowmaker determine the load - not some "text" written on a motor. You are obviously overloading that 40A bkr because it trips. Since it takes 15 min to happen than you are probably running your motor at or near 40A and are doing damage to your motor. Just because a motor nameplate lists an amperage doesn't mean that this amperage is a maximum for any value of load. Or does your motor come with some mysterious internal current limiter?
I would say that for your setup and the fact that you are running near 40A you need a 7.5 to 10HP single phase motor. Sorry.
For the motor you have you should be using a 60 to 70A bkr to allow the motor to start properly. But this does not provide "overload" protection for the motor so you need to install this as well. The overload is a "time delay" unit and will not trip when the motor starts but will trip when it sees a continous load of 125% for a specified period of time. Trust me, you need it. You can't get complete protection for a motor with an "off the shelf" breaker from Home Depot.
You need a "motor starting breaker" complete with overloads - real pricey - or a combination starter with fuses and overloads - generally not so pricey but still expensive. Home Depot may have this item. If they don't have it go to an electrical supplier.

 

[Alex22Vb]

Thank you all for all your help,

Based on what You've told me, I think that I have shorted out the motor. There were a few leaks during the "testing process" and I did not think to cover the Open motor. (MY FAULT)

Is there any way at all to fix a shorted out motor? :
If not then I will be buying an open drip proof or totally enclosed fan cooled Motor, I might even be buying one any way just to avoid this problem in the future.

But in the best intrest of my investment, What can I do to fix it?

Thanks again,
Alex

P.s. It was running off of a 20ft. 10 guage wire.

 

[SteveKW]

Lapalican is a lot closer than you are, Jraef, on the starting current! I would say the 130 amps would be the extreme upper limit though! I'll post what my motor does in the morning. And his link does say cap run / cap start.

The manual overload (Klixon) is a bimetal type and is very reliable the for the first few times it trips! That being said, I suspect the water caused the failure. That is a good brand motor that I am very familiar with and if you did have it overloaded more than 5 amps over nameplate it wouldn't have taken 15 minutes to trip. If it was drawing anything close to 30 amps it would have tripped under 30 seconds!

At the price you paid it most likely wont pay to have it rewound.

A totally enclosed fan cooled motor (TEFC) would be best but you can simply cover the motor properly to insure it wont get wet and save the few dollars over the TEFC.

It may be worth the time to find a Century warranty station just to see what they say ... you have nothing to lose but, at most, a small fee for them to determine the failure!

Pictures of the windings would help too if you can post them. And you would have to put them on, say, your home page and post the link to them.

 

[SteveKW]

Lapalican is dead on on the amperage. Did two 5HP single phase motors and the larger frame hit 125 amps on startup!

I will have to change my opinion of manual klixons... seems they do not work well on motors drawing locked rotor amps. The windings tend to smoke before the overload trips! >:O

 

[Alex22Vb]

Ok,

I seem to have fixed the problem. It now runs and does not blow the breaker. But it seems to be much louder. Of course I don't really know why, but I think that it must be because when I took the motor apart I dropped this "wiggly" looking washer with blueish gress. It picked up alot of dust and dirt, so I wipped it off and put it back in. I did not think that it would matter because there looked to be enough on there that it would disperse. The washer came from the back of the Shaft, against the back "cap" piece (covers the inside of the motor).

What kind of gress is this?

Should I just turn it on and let it warm up and that will spread out the gress?

Or is this totally Not the problem?

I was trying to run it with 4 wire and it takes 3 wire. (duh) :$

So the only problem now is, Why is it so loud???

 

[Alex22Vb]

I have a few pics of the copper wires now and of the "wiggly" washer.

Just click (

http://snowguns.com/eve/ubb.x?a=tpc&s=4826057994&f=6636012705&m=2596019115&r=254108063#254108063

) and scroll down to the bottom, I have post some info. there as well.

Thanks,
Alex

 

[jbartos]

Comment on the original posting: Please, could you post the motor name plate data including manufacturer, model, etc.?

 

[Alex22Vb]

ok,

I have posted more pics that explain the motor. (The sticker on the side of the motor)

http://snowguns.com/eve/ubb.x?a=tpc&s=4826057994&f=6636012705&m=2596019115&r=454105163#454105163

Hope this helps,
Alex

 

[jbartos]

Comment on the previous posting: The link requires registration to some site. I was seeking something more readily available to me and other volunteers not to waste precious time to anyone.

 

[SteveKW]

Or, post your username and password so we can view the pics.

 

[simtricity]

Hi Alex
After reading your mail and learning that you build snow machines it suggests that your background is mechanical engineering.
I think it would be a good idea to invest in 3 types of electrical test instruments,so you can diagnose electrical promblems more rapidly.

(1) Insulation test set-- this instrument would indicate any short between electrical conductors and earth ( motor casing)which could be caused by motor insulation breakdown or water ingress.
(2) Continuity (Muti meter)--With this set you can measure the resistance of the motor windings and therefor determine any electrical variations between windings.
(3)Load monitor (clamp on)-- This would allow you to monitor the currant produced by the motor when running.

On uk application motors are protected by motor over load devices, motor rated circuit breakers are fitted at the origin of the supply.

 

[jbartos]

Comment on Alex22vb(electrical) posting. It is not advisable for an electrical specialist to modify or meddle into mechanical substances that are even hard to understand to mechanical engineers. This is clearly playing "Russian Roulette" with your electric motor that is now very noisy due to a lack of the proper lubricant.

 

[Alex22Vb]

Well I just got to say that my motor is working great and spinning faster (I think that the extra wire was messing with the speed). I have put it all back together and popped the fan blades back on. Now it is moving alot more air. And well I'am not sure about how loud the motor is anymore because the blade cause so much noise from the friction of the air. I'am not sure if it was louder after or not anymore, It still spun the same for the same amount of time so I think that there is enough lubricant (and I called and found out what the lubricant was and I gressed it up). Hopefully It will run for a long time now. I had it on for about 30 min. today. (It actually moves the trailer that it is on ).

Thanks everyone for all of your help,
Sorry about the pics not being able to be viewed, Ijust don't have anywhere else to put them,

Alex