NDK
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Post by NDK on Jan 20, 2013 17:05:31 GMT -5
I wanted to trim some rock yesterday, so I dug out my trim saw & set it up. Plugged it in to get cutting and the motor just hummed. I thought maybe it was cold so I took off the belt, & it still hummed. Gave the shaft a twist to help it get going & sill nothing. I even tried a different extention cord in case the one was too light... Nothin...
Wires are good and it ran when I put it away last time. Any ideas Fellas?
Thanks, Nate
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Mark K
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Post by Mark K on Jan 20, 2013 17:38:20 GMT -5
Leave it in the house for a while. Maybe the brushes are cold enough that some grease is too stiff to allow them to work correctly.
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Post by phil on Jan 20, 2013 17:42:03 GMT -5
Yep. I'd let it warm up.
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Post by gr on Jan 20, 2013 18:24:19 GMT -5
Warming it up will probably fix the prob. If not, it could be the caps on the motor.
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NDK
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Post by NDK on Jan 20, 2013 21:59:07 GMT -5
Thanks guys. I'll bring it in the house & let it sit overnight. We'll see if it runs in the morning.
Nate
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NDK
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Member since January 2009
Posts: 9,440
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Post by NDK on Jan 21, 2013 8:02:39 GMT -5
Well, no dice. I let it sit all night and tried it a few minutes ago. The motor just hummed and it smells a little hot (was plugged in maybe 10 seconds).
I had taken a motor apart last summer, but don't remember if this was the one. I suppose I can pop it open and check the wiring.
Nate
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Post by phil on Jan 21, 2013 12:43:15 GMT -5
If it has brushes, check to see that they aren't "frozen". Have you oiled it lately? They need oiling once a year, 30 drops per oil port. You say it turns by hand, so the rotator isn't locked up, if it isn't the brushes, bugs, or debris jamming it up, it may be you didn't reassemble it right...
Good Luck!
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jamesp
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Post by jamesp on Jan 21, 2013 17:54:52 GMT -5
If it is a capacitor start,it's as mentioned,the capacitor.If it is a brush motor it should start some fireworks soon after humming.Oil them like Phil says.A needle to clean gap between commutator blocks to assure no shorts there.
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NDK
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Member since January 2009
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Post by NDK on Jan 21, 2013 20:45:39 GMT -5
Thanks guys. I'm pretty sure it's a cap start, no brushes. When the temps get above single digits (unless I can convince mama to let me bring it in the house) I'll check it out.
Nate
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Mark K
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Post by Mark K on Jan 22, 2013 18:18:30 GMT -5
Put it in a trash bag and bring it in the house any way. No reason for her to have a problem with that when there is no chance of you making a mess. Once it is good and warm you can take it to the garage and give it a try.
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NDK
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Post by NDK on Jan 22, 2013 21:36:00 GMT -5
I brought it in sunday night. It sat all night to warm up and still didn't run. I'm off thursday, so I'll maybe bring it in and see what's going on inside it.
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Deleted
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Post by Deleted on Jan 22, 2013 22:06:24 GMT -5
I would look for a capacitor first. Some old motors have them under the base. If it is a capacitor start you should be able to spin it as hard as you can to get it going. I had a ceiling fan in my house in Texas that I had to start that way. It takes a pretty hard spin but it should go. Jim
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Post by johnjsgems on Jan 23, 2013 8:45:07 GMT -5
Most capacitor start motors have an external housing held on with two screws. With motor unplugged remove the screws. Often a bad start capacitor will be obviously bad with either a tar like substance or oily residue leaking out. If it looks good, short across the terminals with a screw driver and disconnect the wires. If you have a multi meter use the highest ohm range and measure across the terminals. It should read and then drop. You could have a start switch in the motor end that is dirty or faulty as well. You could have a tired motor ready to be replaced. If it does start if you spin it by hand, try spinning it backwards as well. If it starts backwards the start winding is bad.
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Deleted
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Post by Deleted on Jan 23, 2013 10:19:21 GMT -5
Thanks John. I wasn't much help compared to you. lol Jim
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NDK
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Post by NDK on Jan 23, 2013 22:53:35 GMT -5
Thanks guys - good info! It doesn't have an external capacitor. It will not run if I spin it. It ran last time I used it. Been sitting a few months. I'm hoping something is dirty or a loose wire. It's a dayton 1/3 hp split phase continuous duty. Here it was running in may.
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jamesp
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Post by jamesp on Jan 24, 2013 6:35:11 GMT -5
I probably used to have those motors on my greenhouse fans.They must have had internal capacitors cause they were not findable.Most would spin when i spun the fan(or on windy days the wind would start the humming motor by wind milling the fan).But several would just sit there and hum and get hot and blow the thermal overload,reset,and cycle blowing the OL.Fan motors have a rough life,that saw is easy duty for that motor.It does not sound good.
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NDK
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Member since January 2009
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Post by NDK on Jan 24, 2013 8:17:52 GMT -5
Yeah James I thought it sounds funny in the video too, but I believe that's the blade rubbing on the saw top. I think it's warped a bit. I brought it in the house a few minutes ago. I'll let it warm up then pop it open later and see what's going on.
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Post by johnjsgems on Jan 24, 2013 10:40:42 GMT -5
There will be a start switch in the end opposite the shaft. Other than that there won't be much repairable on that motor. Back in the old days every town had motor repair shops. For a reasonable price they would replace bearings, start switches, etc. Now most fractional hp motors are just throw aways due to high labor cost. You should be able to find a good used motor for less than a repair.
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jamesp
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Post by jamesp on Jan 24, 2013 12:34:28 GMT -5
That is my experience Mr John.$5 at the scrap yard for the old one.There is always a dumpster full of commercial AC fan motors at my Atlanta scrap yard.Updating rooftop units is common.They are great motors.
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NDK
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Post by NDK on Jan 24, 2013 17:09:23 GMT -5
Well I pulled it apart, and all looks ok inside. Put it back together and it hummed and started smoking. It was kinda warm about where the windings are, so I'm junking it. I think my dad might have a motor, or I'll see if any local heat/ac shops have one I can maybe salvage.
Thanks for all the help. Nate
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