Author Topic: Need Some Elec. Motor Help!! (Read 1796 times)

Kevin_H. · « **on:** February 28, 2004, 02:39:29 pm »

Well we tried to put the power to gang saw today...Looks like we may have a problem. When we threw the switch we would blow the 60 amp breaker and the 200 amp main.

The motor is a 10 hp single phase 220. lesson.

Now we noticed a problem with one of the motor run capacitor, it looks like it may have gotten a little hot, we noted this before we ever put the power to it. I figured it would have to be replaced in the future, but since the saw ran when it was taken out of service we thought we could at least put some power to it to see if it would run.

now I have found what I think is a replacement from the surplus center.

http://www.surpluscenter.com/item.asp?UID=2003041712300837&item=22-1183&catname=electric

The difference I can see is that the old one says "55uf/370/60hz
and the new one looks like 15mfd/370/50-60hz

They look identical

I realize this may be a tall question, but any idea if the new one is right?

Any and all answers and questions welcome...

Kevin_H. · « **Reply #1 on:** February 28, 2004, 02:43:13 pm »

Ok I have also found a 50mfd/370/60hz,

http://www.surpluscenter.com/item.asp?UID=2003041712300837&item=22-1119&catname=electric

This one looks a bit heaver...

Norm · « **Reply #2 on:** February 28, 2004, 02:54:21 pm »

That one you found at surplus center will work. The 50mfd/370/60hz, not the 15mfd one. They actually should be labeled with ufd but some of the newer ones use the mfd intending the same thing. If in doubt call them to be sure it is the same. Make sure you hook it up with polarity right. It looks like the wire that was hooked to the caps was too small and caused overheating. You'll want to replace it with new wire is possible. Put new connecters on the wire too.

Kevin_H. · « **Reply #3 on:** February 28, 2004, 03:01:12 pm »

Thanks norm...The wiring is all factory, but we will replace it as it also got a little hot.

This motor has what looks like 2 run capacitors and 4 start capacitors.

Hopefully the new one is the same size as there is only one place it can go.

Maybe I'll giv'em a call on monday

SwampDonkey · « **Reply #4 on:** February 28, 2004, 03:22:38 pm »

This must be what we call the try and fry method which cost more in the end sometimes.

cheers

Kevin_H. · « **Reply #5 on:** February 28, 2004, 04:04:59 pm »

I dont know what is soooo special about that blue smoke, but once you let it out of anything electrical...that's pert near the end of the day

Hey SD the capacitor was "smoked" and melted before we put the power to it, but we thought we would give it a try anyway.

I just looked up the part on the leeson website...They want like 35 bucks for the part...I think it was 7.99 at the surplus center. Hmm.

SwampDonkey · « **Reply #6 on:** February 28, 2004, 04:51:25 pm »

Kevin:

Sounds familiar in pricing strategies. I wanted a replacement battery pack for my Panasonic GPS and they want $137.00, and I found it on Laptops For Less for $50.00. It not in stock, but says it will be available there in March. I'm in no hurry at the moment. Guess where I'm gonna get it from ?

I bought a power supply there quite cheep. I asked locally and never got no return phone calls so I ordered it one night and had it in 24 hrs at my door UPS.

WV_hillbilly · « **Reply #7 on:** February 28, 2004, 06:04:38 pm »

Kevin

We jokingly call it a smoke test at work when something gets hooked up .

I it doesn't smoke your okay .

If it does smoke someones in trouble

and everyone else gets to rib that person for a while . But then again the equipment doesn't belong to us either .

D._Frederick · « **Reply #8 on:** February 28, 2004, 08:09:56 pm »

Kevin,

Take your belts off the motor, tape up the wires that went to your blown out run cap. The motor should start and run without the one run cap, if it doen't start , forget buying a new run cap, the motor armature winding has a short.

ADfields · « **Reply #9 on:** February 29, 2004, 01:24:24 am »

The wife has pestered me for ten years now for crossing the common with a 120v line off the gen-set and feeding 240v to her new Hoover.

Man did it suck great for a bit before the smoking started.

Every time I go to plug something in I hear "Is that 240?" she has got a lot of fun out of that!

---------------------------------------------------------------------------------------------------------------- >:(DanG twist lock plugs anyhow!

Andy

J_T · « **Reply #10 on:** February 29, 2004, 09:05:18 am »

You can go +or - 10% I try to go + as all my stuf is old . You can take a cheep ohm meter a test most capastors a start will rise then fall then reverse leads and try that way I saved a lot ot them off old central units . Have not found one to be polarity conserned .Have replaced some with a hard start kit just cause I had it handy .Blue smoke test not good.

Kevin_H. · « **Reply #11 on:** February 29, 2004, 11:39:07 am »

Quote

Kevin,

Take your belts off the motor, tape up the wires that went to your blown out run cap. The motor should start and run without the one run cap, if it doen't start , forget buying a new run cap, the motor armature winding has a short.

Let me see if I have this right...the wires from the "Smoked" run cap need to be connected (taped) as if the cap was still there in order to complete the circut, Then the motor should start and run.

We wont be back over at the mill until tuesday...Might have to give that one a try.

D._Frederick · « **Reply #12 on:** February 29, 2004, 08:56:32 pm »

Kevin,

You said there was two run capacitor, they are in parallel, so removing one will have little effect. The run capacitors are to correct the power factor so the motor will draw less current. The starting capacitors cause a phase shift with a winding to start the motor rotation, it will not start if these are bad.

sawyerkirk · « **Reply #13 on:** March 01, 2004, 05:11:27 pm »

Hey Kevin, I picked up an old Alden gang/rip the other day at an auction, and am trying to locate blades for it. Whta size arbor does your edger have? This thing takes a 2-3/4 arbor, and nobody has ever heard of such a thing. I am thinking of taking the collars off and using a 1-3/4" arbor, but am still trying to decide why I can't do that! Oh yeah, and I have a 20 hp 3 phase if you want it.

Jason_WI · « **Reply #14 on:** March 01, 2004, 07:11:44 pm »

Those Leeson motors are ropeless boat anchors as far as I'm concerned.

We used a few of them on the farm cause they were a few bux cheaper than a Dayton, or a GE. After three years all of them have been replaced. The Leeson 7.5 hp on the vacuum pump would get hot enough to fry eggs on it. That one has been replaced by a Dayton. The 10 HP Leeson on the silo unloader that we had to drag down the silo twice before was replaced by a 20 year old GE just a month ago.

The run caps melting down on these is common failure.

Do your self a favor and replace that motor. Barely worth shipping ballast cause it's round.......

Jason

D._Frederick · « **Reply #15 on:** March 01, 2004, 07:56:56 pm »

Jason,

What does a volt meter say for the location that the motors burned-up? My findings would agree with you on motor heat, my 7 1/2 hp Baldor on the sawmill get so hot that it smells, I put extra fans on it to reduce the temp. The old U frame motor run cool.

SwampDonkey · « **Reply #16 on:** March 02, 2004, 05:45:50 am »

I wonder how much heat those 300 HP GE electric motors produce at the kraft pulp mill.

I've walked through a local kraft pulp mill on 3 tours over the last 15 years and they have several of these sized motors running throughout the mill. No wonder they have to generate some of their own power.

Kevin_H. · « **Reply #17 on:** March 02, 2004, 06:42:31 am »

I have not tested the run cap that we took out, it looks pretty melted, so it need replaced anyway, the new cap will be here in about a week. I hope that it solves the problem, Leeson tells us that the main reason for a run cap failure is too high an amb. temp or a power spike. Like I said earlier, the run cap looked shot before we even hooked our power to it.

Right now we have more time than money so if we can get this motor to run under power we will use it until something better comes along

Hey Kirk, I'm not sure what the dia of the arbor dia is, I think the blade needs a 2" hole for the collar...I will check today and get back to ya, I think that who ever you order blades from should be able to machine out to the right size, Maybe Menominee saw can help us out with that?

What kind of power supply are you using for your gang?...and keep that 3ph handy, we might need it.

Kevin_H. · « **Reply #18 on:** March 02, 2004, 06:50:31 am »

Hey jason thanks for the heads up bout leeson, If we need to replace the motor I think we will go 3 ph so that we could get a little more hp, The down side is that we will not have 3 ph until we move into the new shop sometime this summer, and a phase converter will cost more than the motor.

Now I know there are ways of building a converter, but I cant get a simple single phase 220 motor to work,doesn't leave much hope for me being able to build a phase converter.

whitepe · « **Reply #19 on:** March 02, 2004, 06:56:35 am »

15 microfarads doesn't equal 55 microfarads.
You need the 55. I was once working on a power
supply and accidentally put a 12 volt polarized
capacitor into a 24 volt power supply circuit.
The voltage looked good for about 2 minutes till
the capacitor let go. I had bits of cardboard, mylar
and metal foil flying around the room

Norm · « **Reply #20 on:** March 02, 2004, 07:10:33 am »

I might disagree with um saying too high ambient or power spike. Heavier wire should help. Perry's right in that 55ufd would have been best but the 50ufd should be alright for a run cap. Of course if I'm wrong I should be far enough away you won't bother to drive up and hit me.

Last week Patty was down in the shop helping me. I hooked the power to a board and a polarized cap snapped and smoked. Now she stands back when I apply power.

Kevin_H. · « **Reply #21 on:** March 02, 2004, 07:29:20 am »

Ahh...The big bang threoy

Well the surplus center didnt have the right one so we called leeson and got the original. Thats way it's taking a week to get it.

I really really hope this solves the problem as the orders are starting to stack up.

Looks like today we are back to ripping stakes on the WM.

We got heaver wire on the list too.

sawyerkirk · « **Reply #22 on:** March 02, 2004, 08:49:12 am »

Kevin, I put a 50hp White engine on it. Should have enough power!!!!!!!!!!! I pulled the collars off this morning and drilled out 4 12" rip blades to 1-3/4" ran a few boards through it so far and seems good so far. I wanna get this thing fired up and run for a few hours to see what gives! Still have a little work to do on the drive chain assembly. Should be operational in a day or so. Spring is coming on quick. I am not an electrical guy either, and the thought of building phase converters, just blows my mind. I got an auction bill this morning for a mill up in Fort Wayne, that has a couple of small gangs, April 3 I believe, might be worth the trip a guy can't have to much junk.

Kevin_H. · « **Reply #23 on:** March 02, 2004, 04:06:52 pm »

50HP !! Yep that should do it. I forgot to measure the arbor on my machine today. I did try to wire around the run cap today to see if it would start but still throwing the breakers

I guess we will wait til the new cap comes in and see what happens then. There should be a way to test with a meter to see if something is bad inside the motor.

If the new cap doesnt fix it, I will have to break down and PAY someone to come out and look at it.

If something with this gang doesnt work out I might be inclined to go to that auction. just hate to throw good money after bad.

SwampDonkey · « **Reply #24 on:** March 02, 2004, 04:33:55 pm »

Keven:

There are instuments and tools to test electric motors but I'm afraid I have no clue. My motors end up at Hargrove or Sarchfield Electric.

regards

Minnesota_boy · « **Reply #25 on:** March 02, 2004, 05:08:10 pm »

Most common meters measure the DC resistance, voltage, or amperage. To test the motor you need an AC impedance measurement.

J_T · « **Reply #26 on:** March 03, 2004, 09:01:28 am »

You can wire differnt capasitors together to get 55mfd .A phase converter is no problem ask Frier Don. Big Co's like to make some things look hard to do .

Kevin_H. · « **Reply #27 on:** March 03, 2004, 03:35:53 pm »

My wife went to town today, she found a place that had the right run cap in stock for 20 bucks...but she didnt get it cause I had ordered one already.

Hey J T
I looked at a phase converter and it looked like a bunch of capacitors wired together...but my knowage is limited

Again if the new cap doesnt fix it i will take off the motor and take it to town.

Hey Don, did you make your own converter?

D._Frederick · « **Reply #28 on:** March 03, 2004, 04:57:27 pm »

Kevin,

There is one more thing you can try if you got more time than money. The single phase motors have a centrifical switch that have points. If the motor has sit around a lot, the points can be corroded or the moving part rusted so that they do not move. To check this switch, take off the end bell opposite the output shaft. The end bell has 4 or more bolts on the rim and there are two bolts that hold the bearing. After the bolts are out, just tap it apart.

You can check the starting caps (the caps with black plastic cases) to see if they are good. Take a couple 12 volt car batteries and connect them in series, - to +, - to + , connect the cap to the + and - leads from the battery. Discharge the cap and you should see a nice spark if the cap is any good.

When you have it (the motor) apart look at the armature windings, if any are black and smell. Throw the motor in the junk pile.

J_T · « **Reply #29 on:** March 03, 2004, 05:51:58 pm »

Hey D much easer to use cheap ohm meter. I beleave Don made a rotery converter the one you are refering to is a static converter. Rotery is better most factory converters use a static to start their rotery one . Don posted a link to a site on such things once I think I sent it to him. Worked seven years selling hardware ,elect. and plumbing. Would post link don't know how that why I sent info. to Don. Me and man up the road built a 50hp he uses every day.

shopteacher · « **Reply #30 on:** March 03, 2004, 06:03:40 pm »

Kevin you could take an ohms meter and check each incoming lead to the case of the motor. If you get a reading you got a short to ground.
Me, I'd put a three phase 10 hp. on it and build a rotary phase converter. All you need to make a simple, but balanced converter, are some run capacitors, a start capacitor, a momentary switch and a good older cast iron frame 10 hp motor. (could be larger to run a 10 hp motor) You can use the newer motor, but they don't seem to work as well, something about making the newer ones energy efficient.
I just built two, one a 5 hp. and a 10 hp. converter.
Here's a thread I posted a while back on a converter I was making if you go toward the end I think you'll find some pictures of the components.
http://www.forestryforum.com/cgi-bin/board/YaBB.pl?board=general ;action=display;num=1073845355

J_T · « **Reply #31 on:** March 03, 2004, 06:21:06 pm »

Shopteacher on our 50hp we use a small 110 motor to start it cheper than capasitors it you have to buy them I don't I got a bunch on hand . I would make sure to enclose all capasitors as I have seen them explode .I don't post anything I haven't tried myself for some reason I didn't post much when you were building yours maybe cause me and Frier Don all ready did it on the FF.

Kevin_H. · « **Reply #32 on:** March 03, 2004, 06:53:46 pm »

Thanks for the links...very interesting...I hope the single phase motor will come to life, but If is doesnt I will be tempted to park the gang until this summer, our plan is to have 3 phase in the new shop.

We are only about 100 feet away from 3 phase now, but no since running it in if we are going to move.

Hey Teach, I will try the ohms meter test on friday, It might save me any more work.

shopteacher · « **Reply #33 on:** March 03, 2004, 07:09:01 pm »

J_T using a pony motor to start the three phase is one way of doing it. However you only achieve approx. 80 efficiency from the converter motor and probably don't have a very balanced output voltage. If you check between each of the three output leads you will probably see one leg with much higher voltage. The converters I built were deriving an output voltage of only 2 volt difference between any of the output leads. I had a converter connected to my milling machine that had that one high voltage lead and the motor would get so hot it would kick out the thermal overloads in the starter. You can also get a static converter that is basically just a start cap and a potential relay. The start cap kicks the three phase motor over and the potential relay disconnects the capacitor once voltage is detected in the manufactured lead. They're cheaper to purchase but here again the motor is only running at about 80 %.

J_T · « **Reply #34 on:** March 03, 2004, 07:49:45 pm »

Shop teacher our 3ph reads 110-110-180 call it wild leg common around here . Our converter been running over a year ever day . No converter puts out 100%. reson we went 50hp got several peaces on line can run several small things on same converter same time up to or around 40horse 35 is good. Some times you can get 25hp motors almost free here.

shopteacher · « **Reply #35 on:** March 04, 2004, 03:53:10 am »

Your right J_T no converter will put out 100%. The readings between any two of the three legs on mine are 240, 238, 239.
The general consensus as to what you can run is no one motor bigger than the motor used for the converter or a combination of motors totaling twice the converter motor. 10hp can run a total of 20 hp with no one motor exceeding 10hp.
I'm not saying you don't have a good system and know quite a few shops that run converters exactly like the one you mention. I was just siting an situation where it didn't work out to well.
The 10hp I built has a remote control. As it will be stationed in a 2 story building. I don't want it to run constantly so this way I can start and stop it at anytime or anyplace inside the building. A lot of my equipment is single phase and only need 3 phase when using particular pieces.
Your right about getting three phase motors cheap. I paid 27.00 for the one I used and it weighs 400 lb so I think I could get more for as scrap than what I paid.

D._Frederick · « **Reply #36 on:** March 04, 2004, 07:53:59 am »

J. T.

I would like to know what kind of 3 phase motor that you have that will run on 110 volts?

I agree with you that you can do a lot of trouble shooting using a ohm meter, but you have to have a wiring diagram of the motor. Some times you can find out the problem by just looking.

D._Frederick · « **Reply #37 on:** March 04, 2004, 10:14:31 am »

J. T.

I guess that I misread you post about the voltages, I thought that you were reading your converter voltage instead of the line voltage from the power company.

shopteacher · « **Reply #38 on:** March 04, 2004, 04:11:26 pm »

D, I think he is reading output to neutral. Two of the output leads will give a reading the same as the source voltage. The manufactured leg (wild Leg) will be a much higher voltage in this case 180 V. I just feel you can get a much closer to true three phase using 2 banks of capacitors. By taking readings and adjusting the capacitance you can get the output voltages very close.

Kevin_H. · « **Reply #39 on:** March 17, 2004, 02:37:27 pm »

Well we got the electric motor to run today...We replaced bolth run caps. but still had a problem so we went back to square one and found that to of the leads in the wireing box were mismatched, Something like T5 and T8 were wired up backwards...

Anyway we made a little sawdust before calling it a day.

Just a little side note for Electric al...Linda was right... the rear roller is a pain in the keester, but we have a plan.

Stay tuned for "As The Saw Turns"

Fla._Deadheader · « **Reply #40 on:** March 17, 2004, 03:11:04 pm »

Way to go, Kevin. Perseverance pays off one more time.

Stan · « **Reply #41 on:** March 18, 2004, 08:37:23 am »

Teach, 80% power factor is the way 3 phase alternators are rated. The thermal plant I worked at they were rated 156,250 kW at 80%. We usually got 180,000+kW out of them.

News:

Author Topic: Need Some Elec. Motor Help!! (Read 1796 times)