Hardcore Grinder Problem

adammichael

adammichael

Joined
Sep 13, 2004
Messages
1,553
Last week I started blowing fuses constantly on my hardcore grinder. I found a couple loose wires in the base and tightened them up. That didnt work so I replaced the comtroller, that didnt work either. I have been using this for about 4 years with no issues and it just started blowing fuses. Anyone have any ideas what might be wrong?

It is a baldor motor, 1 1/2 horse 15.5 amps. Also, it has a 15 amp fuse in it and the motor is 15.5 amps. Shouldnt the fuse be bigger than 15.5 amps?

If any of you have a Hardcore could you please check your fuse and tell me what it is rated at?

Any help would be greatly appreciated.

Thanks

Michael
 
would make sense that the fuse needs to be bigger amps than the motor itself as the current that's drawn through it would overload the fuse and that's why it keeps blowing. Try putting in a 20 AMP fuse.
 
A motor is not delicate electronics, it doesn't need a quick short fuse. And remember, start up amps is easily twice full load amps. It should be a slow blow fuse and probably 20 amps.

With that said, metal dust has been known to short out a motor....
 
Make sure everything is clean...start there first!
Stay Safe & Blessings!
 
I had a 15 amp fuse in it for the last 4 years and it just recently started blowing the fuse.

Anyone out there have a HArdcore grinder? Could you check the fuse and see what size it is?

I replaced the controller and cleaned out and tightened all connections and it still is blowing fuses.

All the fuses that have been in it so far have been slow blow.
 
If the 15 amp fuse is in the controller, then DO NOT PUT IN A 20 AMP FUSE. The electronics in the controller do need more protection than a motor. The motor may be getting dry and dusty and drawing more amps now. A check with an ammeter on the motor draw should tell a lot. If this is an AC motor,try running the motor directly from the AC source without the controller. Use a 15 amp circuit if possible. If it runs fine for five minutes, I would suspect the controller is just slightly underrated for your motor.

Solutions:
Take the motor apart and thoroughly clean all of it. Check seals and bearings, Replace as needed (or put it in the motor shop for inspection and rebuild if needed).
Make sure there is no dust buildup on the controller heat sinks and box.
Check all wiring for wear and tight connections.Look closely at the junction box on the motor.
A clean ,well lubricated motor draws less current.
Hope this helps.
Stacy
 
Adam

I think you have a shorted winding or the startup caps are shorted out. If you blow up the fuse on power up, then look at replacing the caps. If it dies after 30 seconds or more or when you start to load the motor, you have a shorted winding.
Check motor's warranty or contact an electrical motor repair shop.

Don't put a bigger fuse in for long as its a potential fire hazard.

Frank
 
bladsmth said:
If the 15 amp fuse is in the controller, then DO NOT PUT IN A 20 AMP FUSE. The electronics in the controller do need more protection than a motor. The motor may be getting dry and dusty and drawing more amps now. A check with an ammeter on the motor draw should tell a lot. If this is an AC motor,try running the motor directly from the AC source without the controller. Use a 15 amp circuit if possible. If it runs fine for five minutes, I would suspect the controller is just slightly underrated for your motor.

Solutions:
Take the motor apart and thoroughly clean all of it. Check seals and bearings, Replace as needed (or put it in the motor shop for inspection and rebuild if needed).
Make sure there is no dust buildup on the controller heat sinks and box.
Check all wiring for wear and tight connections.Look closely at the junction box on the motor.
A clean ,well lubricated motor draws less current.
Hope this helps.
Stacy
Click to expand...

It is a DC motor and it is clean inside. No dust, no hot spots. I used this very little in the last 5 years. (part time maker, spent the last 8 months making MAP Arms) all connections are tight. This is the controller that was sold with the Hardcore grinder and it has been working fine for the last 4 years.
 
Frank Barron said:
Adam

I think you have a shorted winding or the startup caps are shorted out. If you blow up the fuse on power up, then look at replacing the caps. If it dies after 30 seconds or more or when you start to load the motor, you have a shorted winding.
Check motor's warranty or contact an electrical motor repair shop.

Don't put a bigger fuse in for long as its a potential fire hazard.

Frank
Click to expand...

I dont mean to sound ignorant but where are the startup caps?

The fuse blew the first time when I was tapering a tang on the flat platten.

thanks
Michael
 
There are no capacitors in a DC motor, so that isn't the problem.

I had the exact problem a couple of years ago with my 1.5HP, DC Bader BIII. The controller fuse kept blowing. I couldn't find a problem. Blew ten or twenty fuses, some on start-up, some after a few minutes running. I did what I posted - cleaned everything (especially the heat sinks) and the problem went away. I haven't blown a fuse since. Hope it goes as well with your situation.
Stacy
 
If you don't have an air compressor for the shop, get a small one just for cleaning things. I always blew out my motors and the controllers and the grinder. You have to keep the crap out of the electrical stuff or you'll burn down your shop!
 
bladsmth said:
There are no capacitors in a DC motor, so that isn't the problem.

I had the exact problem a couple of years ago with my 1.5HP, DC Bader BIII. The controller fuse kept blowing. I couldn't find a problem. Blew ten or twenty fuses, some on start-up, some after a few minutes running. I did what I posted - cleaned everything (especially the heat sinks) and the problem went away. I haven't blown a fuse since. Hope it goes as well with your situation.
Stacy
Click to expand...
There are no heat sinks to clean. The controller is enclosed in the base of the motor. It is a new controller and the motor was blown clean when the controller was replaced.
hardcore.jpg
 
Michael,
I have a Hardcore grinder like yours. Mine is powered for 110VAC and I just checked and it has a Bussman MDA 25A fuse. Is yours powered by 110 or 220 volts? That may the difference in the fuse sizes.

~or~

On the nameplate on my motor it has an amperage of 15.5 amps. Possibly did you blow a fuse in the past and replace it with a 15.5 amp fuse instead of a 25 amp fuse? I am just curious...

These motors have no capacitors and are of the DC variety. Check out http://www.baldor.com/ and see what you may be able to come up with. Even if there is a problem with the motor it should be repairable (unless a new one would be less expensive than the cost of repair) but your grinding will come to a stand-still while it's out for repair.

One thing I would check (if you haven't already) is to ensure that the contact wheel is free spinning and not binding with anything. I have blown fuses before when I got in a hurry when I was putting the flat platen on and didn't ensure that it wasn't making contact with the wheel.

If you need me to look at anything else on mine let me know. Post it here or send me an email.

Craig
 
Micheal, I had a hardcore just like yours before my fire in 2005. Only time I had problems with fuses is when I tried to hog too much off at one time. I bought 15 amp fuses at Radio Shack and they worked just fine. Maybe the dust but what I can remember mine was sealed up real well. Beware this machine will melt when the temps are over 1700 degrees.
 
Has there been any changes in line voltage coming into your shop? Every once in awhile around here in the rural area we get drops in voltage, perhaps when too many airconditioners are running, or when the utility drops voltage for whatever reason. When that happens I sometimes blow the internal fuse in my DART regulator for the leeson DC controlled motor on the Wilton.

I was checking connections wondering what the problem was until I noticed that the line voltage here was running abit low 110 volts when it usually is 118- 120 VAC. Its not much of a drop, but a drop in voltage will equally correspond in an increase in amperage during operating loads. Its the old rule of electricity, 'voltage goes down amperage goes up'.

Check your line voltage when things are running well, and again when fuses are blowing to see if this causing problems.
 
Michael,

I'm not familiar with your particular grinder but a few things you can try to isolate the problem are;

1) With the sanding belt on the grinder, pull the sanding belt by hand and check for tightness or binding- possibly a bad bearing in one of the wheels.

2) I can't tell from the pics, but if there is a drive belt under the cover in the grinder, disconnect it and run the grinder to see if it still blows fuses. If it still blows fuses that would isolate it to the motor section of the grinder.

3) If there is no drive belt, run it without the sanding belt attached and that will isolate the problem to the motor section as well.

Brad Anderson
 
rfrink said:
Michael, it might be time for a new set of brushes in the motor.

-Rob
Click to expand...

Michael,
Go ahead and do what we discussed today. That should work just fine. After thinking about this, Rob may very well have a good point. You didn't have the problem with the blown fuses before. Recall we talked about that possibly the brushes may be worn or have a groove in them. It wouldn't hurt to get some brushes on the way and they aren't that expensive. You will ultimately need to replace them eventually and they will be on hand when needed. As a matter of fact, I am going to go ahead and get a set for mine as well.

As mentioned, I have a 25 amp fuse in mine and have never blown a fuse but I have tripped a breaker before when some idiot knifemaker (the same one that is typing this response right now) misadjusted the flat platen and put a bind on the contact wheel!

Craig
 
Michael,

I have the same motor and the same problem. I will be interested to read what finally works for you.

Best,

John
 
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