Need Help - Electric Motor Hot?

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gunner66
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Need Help - Electric Motor Hot?

Post by gunner66 »

I have an old 1957 Greenie with the original 3/4 hp motor. I put about 1/2 cc grease in each shielded bearing (grease had dried out, but the bearings seem o.k. otherwise). After greasing, the bearing rotated easily with minor resistenace, but not absolutely "freewheeling" (like a dry but otherwise o.k. bearing). I blew the inside with compressed air and it was was very clean. My question is:

I am running it on my workbench and the entire motor's case seems to be hot to the touch after 20 minutes (can hold palm on motor and not burn hand, but is above "warm"). The area around the bearings don't seem to be any hotter than the rest of the case. Is it normal for the motor to run and be hot to the touch? My only concern right now is that the motor is hot because the bearing are perhaps putting a load on the motor. Thanks for your help.
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gunner66
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More info

Post by gunner66 »

Here's some additional info:

It is the General Electric motor. The placard does not provide the "amps" it should draw and the "temp rise" field is blank.

Perhaps someone knows the approx. amps it should be drawing at "no-load" or "load"? (I have an ammeter). Thanks, Chris in Georgia
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gunner66
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Amps

Post by gunner66 »

More info: on the bench, it is drawing 8.4 amps at no load.
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dusty
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Post by dusty »

The motor housing does get warm. If you can place your hand on the housing and not have to pull away, I think the motor is OK. I have some charts, somewhere, that show current draw on my motors. When I locate them, I'll postscript to this thread..
"Making Sawdust Safely"
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wa2crk
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Post by wa2crk »

The 1 1/8 HP motors have a fan sheave on them to move air around the windings and I believe that the 3/4 HP motors are the same. If you run the motor without the fan sheave attached I remember that the frame gets warm within a few minutes. Without the fan sheave a bench test is a different set of circumstances than normal running. Is the centrifugal switch working properly?
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Post by garys »

I found an NEC motor amperage chart. They show full load for a 3/4hp motor to be 13.8 amps, so you are probably OK with no load of 8.4 amps.
http://www.electricmotorshop.net/index. ... Itemid=249
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gunner66
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Post by gunner66 »

Thank you everyone for the quick replies:) . The capacitor, and start relay seem to working properly. The motor starts easily, runs smoothly at its normal rpm, and when I chop power it winds down appropriately.

I have learned so much about using and maintaining my SS from this Forum - thanks to contributors like yourselves. My "greenie" has always been my favorite tool!
Thanks again, Chris in Georgia
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