Tommy
Administrator
Member since January 2013
Posts: 12,886
|
Post by Tommy on May 21, 2015 20:24:43 GMT -5
I bought this motor at Harbor Freight around six months ago and it has already crapped out. The pulleys and blade spin very freely with no hangups but the motor has had harder and harder time getting started lately. For a while I've been turning it on and giving the pulley a spin and it will fire up and run normally. Now it just runs slowly backwards until the overload trips. Could this be the capacitor and does anyone think it's repairable? Once in a while if I turn it on and spin it in the right direction it will catch and run perfectly normal.
|
|
|
Post by DirtCleaner on May 21, 2015 20:59:36 GMT -5
Sorry, no help for the motor you have. But in the future start looking for good, used motors. Watch the local free paper (shopper), Craigslist, estate and rummage/garage/tag sales. I run across MANY every year for $5 or less. Often you will need to put a power cord on to get them going. Most all have spec plates on them so you will know how they are powered. Then take the savings and buy some rocks!
|
|
|
Post by Rockoonz on May 21, 2015 21:25:29 GMT -5
Probably the starting capacitor, may even be a loose wire. That's what happened to a Chinese motor on a saw at the clubs shop awhile back. Hooked the wire back up and it worked fine. Another motor from grizzly, which is basically HF painted green, was fried. Careful with the spin starting, a friend mangled his hand pretty good that way.
|
|
|
Post by woodman on May 21, 2015 22:43:07 GMT -5
Does sound like a capacitor problem. take ethe cover off the capacitor and if the wires are good take the numbers off the the capacitor and see what you can find.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,561
|
Post by jamesp on May 22, 2015 0:50:52 GMT -5
Capacitor probably. had one burn up after a year on a brand new pump motor. An expensive one at that.
|
|
|
Post by pauls on May 22, 2015 4:49:42 GMT -5
The capacitor will be in that box on the top of the motor, they sometimes have quick connect terminals on them but often are wired back to a terminal panel inside. It shouldn't be all that expensive to fix. It wont necessarily be burnt like on James' pump motor but could look perfectly OK and still be shot. It could also be the switch points that switch it out of circuit once the motor has started, I had a bug crawl between the points in my expensive pump motor, tried a new capacitor and nearly bought a new pump for several thou when I spotted the bug remains, scraped em out and away it went.
|
|
QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,640
|
Post by QuailRiver on May 22, 2015 12:46:11 GMT -5
I had a similar thing happen to an older U.S. made motor I was using on a slab saw. One of the wire's terminal connector clip had gotten up against another wire and was shorting out. So I would first take the terminal connector plate off and inspect wires and connections for a short. If they all look okay then I'd check the capacitor. Larry C.
|
|
|
Post by jakesrocks on May 22, 2015 13:07:28 GMT -5
If you have the push on type connectors, heat shrink tubing is your friend. Pull the connectors off one at a time. slip a piece of heat shrink tubing over the connector and a short distance over the wire. Heat it with a hair drier set on high heat to shrink the tubing. Do this to each connection. No more shorting problems. Lacking a hair drier, a match or cigarette lighter will do the trick if you don't overheat & melt the tubing.
Heat shrink tubing can be found at any auto parts store in various sizes. Handy stuff to have an assortment of.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,886
|
Post by Tommy on May 22, 2015 23:34:01 GMT -5
Thanks everyone for all the response. I'll take it apart tomorrow and see if I can find anything obvious wrong in the wiring.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,886
|
Post by Tommy on May 23, 2015 16:32:26 GMT -5
Aside from the chassis ground wire having come off I can't see anything wrong.
I disconnected the capacitor - and even jumped the wires and no difference - all three conditions (connected, disconnected, jumped) result in the motor turning backwards slowly. Does this confirm or deny that the capacitor is bad?
|
|
|
Post by pauls on May 23, 2015 17:17:22 GMT -5
The capacitor is in the start winding, so naturally anything wrong with it means the motor wont start. A quick dose of way too much information. The capacitor is in circuit when you start the motor, it slightly changes the phase of the electricity going into the start winding so that it pulls the armature around and gets it started, once everything is rotating at the correct speed the points open and the start winding and capacitor are switched off. The capacitor can be shot and look perfectly OK, shorting the wires etc will do nothing as all you will be doing is feeding electricity at the same phase as the run winding to the start winding, nothing to pull the armature around. You should be able to pick up an identical capacitor for around $10 to $20
What can be wrong Capacitor, cheap to fix wiring open circuit, could be cheap if you are capable start winding open circuit/ burnt out. expensive to rewind, get new motor points, the switching points are operated by a governor, they could be dirty or just need a slight adjustment. cheap and fixable. (not cheap to replace though)
Really the best option would be to take it to a specialist if you don't really know what you are doing, electricity can be nasty stuff.
|
|
Tommy
Administrator
Member since January 2013
Posts: 12,886
|
Post by Tommy on May 23, 2015 21:16:53 GMT -5
Thanks Paul - thanks for the explanation of what the capacitor does. I will try to get another one then that's about the end of my attempts to fix it. I've got a healthy respect for electricity - I've done a lot of residential wiring projects over the years but I would not pretend to think I could pull a motor apart and fix it.
|
|
quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,352
|
Post by quartz on May 23, 2015 22:41:24 GMT -5
A motor shop can check a capacitor, take it with you instead of just buying one.
|
|