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Need help with 5hp motor

6.5K views 30 replies 10 participants last post by  Herb Stoops  
#1 ·
Hey guys and gals, I just acquired a used "nonworking" tablesaw. It's got a 5hp single phase 220v motor. Initially the motor was packed with sawdust and wouldn't turn. I cleaned that and replaced the bearings. Now it still doesn't always turn, or turns slowly and blows the breaker, (30 amp double pole), and/or turns backwards. There is evidence inside the cabinet that @ one point the blade came flying off, probably due to the motor spinning backwards. :surprise:

What would cause this?
 
#4 · (Edited)
wiring on the motor for the CCW rotation...
not coming up to speed...
start cap no good...
start switch not engaging or disengaging...

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#6 ·
I don't see this motor reversing polarity, it's a random shift between the 2 directions. Sometimes it's clockwise, other times its not, just depends...but on what, I don't know.
 
#7 ·
Coils LOOK good, how do I verify that they are?
 
#9 ·
Did a quick experiment, tried starting motor with leads reversed on capacitor, then tried starting motor with capacitor discuss connected. Both resulted in the VERY SAME SYPTOMS I have been experiencing right along. Also, when making an effort to discharge the capacitor, there were no sparks or arcing of any kind.
 
#14 ·
new capacitors are in order...
take note about run and start capacitors in the PDF....
 
#11 ·
Phil, maybe. The guy I bought it from claims he already replaced the capacitor. At the very least, I can't be truly sure that the current capacitor is the correct one.
 
#12 ·
I can't find ANY info about this motor or its manufacturer.
 
#15 ·
Ok, FINALLY got to a laptop so can write stuff, typing on the phone is horrible!

So yes Stick, I will read the PDF, however, my motor is single phase and only has 1 capacitor. There is probably info to be gleaned from the article anyway so yes I WILL read it tonight.

I am having issues with page layout and function tonight. Am I the only one? I'll start a new thread with this question.
 
#17 ·
Id call that cap a start cap...
 
#18 ·
Sounds like the start/run capacitor. Just make sure that the replacement is in the same range as the old one. The microfarad will be within a certain range and marked on the capacitor.

I was given an old Grizzly shaper that wasn't running. I found a place in California on the internet that was very reasonable. $6.60 later it was fired up, and that price included shipping to FL.

If you are in doubt find a local shop that rebuilds electric motors. Usually, they can determine what is needed and supply it at a reasonable cost.
 
#19 ·
So here is my capacitor. It has 2 leads, hopefully when I got it, it was hooked up correctly.
 

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#20 ·
play it smart...
take the motor to a motor repair shop...
let them value a new cap, double check the wiring and they just may check out the motor (field/armature) for little or no money...
if you have to replace the motor do not but a chinese motor...
 
#23 ·
So, I did the unthinkable, I took my motor in to a local motor shop. I didn't completely fix it myself, I'm paying someone else for their knowledge. I get the peace of mind that whatever happens now, it's done right, not just a lot of guessing.
The motor may be bad, but let's hope not. All along I thought I could fix it, oh well. I think I still got a deal on the saw.
 
#25 ·
I did that awhile back with my dust collector motor. I couldn't get the fan impeller off to look at the motor insides. They called and said it was toast and I needed a new motor, Charged me $45. to look at it and test it out. They kept the motor for junk and I got the impeller removed and the housing back for a new motor I ordered off ebay.

Herb
 
#24 ·
Thank you to every one who offered constructive suggestions.
 
#26 ·
Hey Herb, good to hear from you! This guy told me $20 to check it out, and he came recommended from a friend.
 
#28 ·
Yup, I always check out what's available online, I'll search for weeks sometimes trying to get the best price.