Need help with a Leeson 1.5 HP electric motor

Tom Lewis

Tom Lewis

Joined
Feb 24, 2000
Messages
1,862
I have a Burr King grinder with a 1.5 hp Leeson direct current permanent magnet 120Volt motor. The control box says "Leeson speedmaster motor control"
Two days ago I used the grinder and everything seemed fine. The next morning when I turned on the switch nothing happened. I opened the control box and saw two fuses. I replaced the first fuse and then the grinder ran fine. I used the grinder and it seemed OK. This morning I turned the switch on and again nothing happened. I have not yet tried replacing the fuse as I think it must have more of a problem than just a blown fuse. It seems like when the motor is turned off overnight, something is causing the fuse to blow.
I might say about all I know about electric motors is you plug them in and turn them on and off.
I have had this grinder for almost 30 years.
Thanks for any suggestions.
 
The fuses might be working together in some manner. I've had this happen in my truck. I'd replace both fuses and see how it goes.
 
Motor has no brushes right ?
Does the controller have braking resistors ?
Are they blown?
Any trouble lights ?

Model number ?
I bet KB makes that controller
 
Yesterday evening I started to change out the other fuse but first I turned the switch on and the motor started. I am beginning to think the problem is the switch.
Thanks for the suggestions I will let you know how things turn out.
 
The model # is C4D28FK13A
This morning the motor would not run. I opened the control box and checked the fuses and they seemed good. I checked continuity on the switch and it seemed good. I closed the box and the motor ran. I also checked the fuse I took out and it seemed to be bad.
Maybe there is a loose connection.
As far as brushes, braking resisters, I don't know enough about motors to know. It does have a light that comes on when the motor runs.
Any suggestions will be appreciated.
 
After 30 years, it's truly possible the switch is worn out.

Switches can show continuity on a multimeter and not under load.
It's a cheap place to start.

The breaking resistor will be in the controller. See if you can find a manual online.
 
I agree with Stacy. More than likely, your brushes have finally reached the end of their life. The motor should have a nameplate with a model number on it. You can use this to find some replacement brushes online, or there's a good chance if you call Burr-King, they'll be able to sell you some, or at least tell you a part number. There will likely be two covers on the outer periphery of the motor, just forward of the fan shroud. On older motors, they're typically a rectangular cover with a couple of screws holding them on. Unplug your machine, and remove the covers. You should be able to inspect the brushes pretty easily, and may even be able to still read a part number here as well. Even if you see some brush left, they likely still need replacing, as they'll be at the end of their usable spring travel.
 
Thanks for the help. I will check the brushes. Sometimes when I turn the motor on it runs, but then a few hours later it doesn't run. Last night it ran and I unplugged it rather than use the switch. This morning when I plugged it in, it didn't run, so maybe that rules out a bad switch.
thanks for all the suggestions. I will let you know how it turns out.
 
Tom Lewis said:
Thanks for the help. I will check the brushes. Sometimes when I turn the motor on it runs, but then a few hours later it doesn't run. Last night it ran and I unplugged it rather than use the switch. This morning when I plugged it in, it didn't run, so maybe that rules out a bad switch.
thanks for all the suggestions. I will let you know how it turns out.
Click to expand...

Hey Tom, you might check Sutherland's, they have a bunch of carbon brushes in the little bins in front of the tool area... They might not have the right ones, but it's a good place to start, I think...

There's also that electric motor repair joint on s. Main St. They might have the brushes on hand too...
 
IIRC, that motor has brushes with screw caps over them. Obviously, unplug the unit before changing the brushed. They are easily sourced from many places as well as Leeson. They run about $20 or less a set. Buy a spare set and tape them on the side of the motor for future need.
 
Today the motor would not run. I took out this item, put it back in, and the motor ran.
From the picture does this look like it needs to be replaced?
Hv9TwLL.jpg

hzq9cJ8.jpg

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Thanks for your help.
 
As I said, the brushes may be near the end of their spring travel, and not giving adequate pressure against the armature. You're almost always gonna see quite a bit of carbon brush left, even when they're ready to be changed. You also want to remove the opposite brush and inspect it. Sometimes brushes don't wear evenly, or one of them starts fracturing and affecting the motor's ability to run correctly.

If you insert the brushes until they touch the armature (I.E., they won't push in any farther), how much spring is sticking out past where the cover plate would contact it?

Either way, I'd order a new set of brushes, but in the mean time, you can bend the spring back out so that the cover plates push down on them a little bit harder when they're installed. This will likely give you a little bit of extra service life. Sometimes the springs just take a set after sitting for so long, and need to be stretched/bent back out a little bit. Just try a little bit at first. Also make sure that the concave faces of the brushes are clean, and worn relatively evenly. You may also benefit from spraying a little contact cleaner into the brush holes while turning the motor by hand. In the absence of contact cleaner, brake cleaner or simply some compressed air is better than nothing. No need to hose it down or anything, just give it a quick spritz or two, then blow it out with some air. Clean the brush ends as well, just don't flatten them out or change the radius of the ends, as they'rel currently matched to the OD of the armature.

Also make sure the contact area around the screws and connectors for the brush leads is clean. Might not hurt to take a wire brush or fine grit sandpaper to the ring connections on the ends of the brush leads as well. From the pics, everything looks pretty clean, but it doesn't hurt anything.
 
Also, there may be a number or engraving on the back side of the brushes that will make ordering easier. If not, give Leeson or Burr King a call and see what they say. You can get replacement springs as well, which shouldn't be more then a few dollars each.
 
Thanks for the suggestions. The brush does have a number printed on it.
610
900015-02
The brush has a different kind of spring as the pictures will show.

<a href="https://imgur.com/uqRYXcg"><img src="https://i.imgur.com/uqRYXcg.jpg" title="source: imgur.com" /></a>
3lAPJ2C.jpg


I have tried several internet sites but have not been able to find the exact brush. I will try a local electric company tomorrow. I also have not yet tried to contact Burr King.
Thanks again for all your help.
 
https://www.finditparts.com/product...2I-OAtMfEaIMWMixEQep6W3tSeQNepnkaAgd6EALw_wcB

There are the springs. Looks like yours might be a little stretched. The clips should still be fine, though you can find those on the site above as well.

According to this page: http://www.electricmotorwholesale.com/LEESON-900015-02/ , the 900015-02 have been superseded to the 900015-18.

Here's a set for a decent price: https://www.galco.com/buy/Leeson/90...vMmC38-AszhbsU-hUWXXe0nZhINxH7-MaAii7EALw_wcB

You can verify that the dimensions are the same (minus the length, obviously, which should be somewhat shorter on your existing brushes).

Looking at the dimensions of what the 18s are, and looking at your picture, it looks like your brushes may not really even be that bad. could just be your springs need replaced, or you need to clean your armature.
 
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You can also find some 610 900015-02 sets on eBay, though they’re gonna be pricey.
 
Drew, thanks for the information. You are better at finding electrical parts than I am. The information will be very useful.
I showed the brush to a company in town that works on electric motors. They said they didn't think it was worn out but that it was not making good contact. So I will try a few things before I order new brushes.
Thanks again for the help and information.
 
I took the brushes out, cleaned them, put them back in and the motor started. Five minutes later the motor would not start.
Anything I should check beside the brushes?
 
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