Grizzly G0440 Cyclone Blowing Starter Caps

[glenn bradley]

This machine has been a champ since January of 2009 when I installed it. In November of last year it blew a starter cap. I do cycle the thing often but, involved Grizzly tech support to be sure. The initial recommendation was to inspect the area around the centrifugal switch, clean contacts and assure proper adjustment, confirm proper power at the proper locations and then replace the starter cap.

I had marked the original factory position of everything back during install as the cent-switch squeaked and I wanted to fix that (which I did). Everything was in the same position it had been since installation. I inspected, confirmed and cleaned, installed the cap and promptly blew it up. Tech support had me dig in deeper and clean more aggressively. I put in the second cap and it ran great for about a month; it just blew again. I have notified Grizzly tech support again but, thought I would put this out to the community.

Power has been verified between lines and between each line and ground. I can find no ground fault at this time and power is as it should be. The cent-clutch moves properly and the switch mechanism move freely. When the cent switch opens there is a disconcerting sparking between the feed contact and the bracket that acts as the stop for the cent-switch when in the open position. This may be normal but, the sound that sparking makes is the same (or vary similar) sound heard repeatedly just before the cap blows. The sound goes for several seconds; long enough to be noticed but, too quick to allow me to get to the switch before the cap pops.

[Alan Bienlein]

Are you getting the caps from Grizzly or local?

[Alan Bienlein]

Hey Glenn here is a link about start caps to help you trouble shoot.
http://www.capacitorformotor.com/start_cap.html

[Alan Bienlein]

And one more specific to start caps.
http://www.capacitorformotor.com/starter_capacitor.html

[glenn bradley]

Thanks Alan. Replacement caps have been from Grizzly so far. They do not have a bleed down resistor and the noise described in the video is said to relate to the speed switch which may be the same as the centrifugal switch(?). There is a magnetic switch on the unit and there are adjustments there but, I have not touched (or been instructed to touch) any of those. I believe they are mag-switch specific at any rate.

[Alan Bienlein]

Yea the mag switch has nothing to do with the start caps. Did the original cap have a bleed resistor on it? I know the 5hp leeson on my dust collector has one on the start cap.

Either the centrifugal switch is hanging a bit or the caps are just bad. Maybe see if you can get a higher voltage start cap.

[Stephen Cherry]

Either the centrifugal switch is hanging a bit or the caps are just bad..

That's what I vote for. The start cap should switch out quickly after the start, or it will blow up. It should not be sparking at the switch for a few seconds.

[glenn bradley]

That's what I vote for. The start cap should switch out quickly after the start, or it will blow up. It should not be sparking at the switch for a few seconds.

The cent-clutch seems to move properly but, once opened there is still some sparking. Its almost like there is a little too much juice for the air-gap on the cent-switch. It had worked for three years of near daily use until this nonsense began. I assume that my previous efforts only served to disguise the real problem and it is yet to be identified. The function is pretty fundamental so I would not rule out poor caps. The originals nor the replacements had resistors. The problem seems to be completely start-circuit/mechanics related.

[Alan Bienlein]

I don't know if you got it apart yet but take an ohm meter on a high setting and check between the contacts and the insulating material they are attached to to make sure there are no carbon tracks that were caused by the excessive arcing.

There is a link on that site about bleeder resistors. Possibility it might help as once the contacts open the resistor will bleed off any residual charge left in the cap.

[glenn bradley]

The cyclone issue derailed my shop efforts and I got way-laid throughout the afternoon. I plan to hit the cyclone first thing tomorrow and go through much of the info in the links Alan provided (thanks again Alan, good stuff). After I certify that everything else is (or was) within spec I will start thinking on applying a little science to make things better.

When I was researching machines one of the topics that came up was the use cycle that would be applied. Being a one-man hole shop I did turn the machine on and off frequently throughout a shop session but, I did this for three years without issue. Other makers advise against running the machine for less than an hour or so at a time, preferably for hours at a time. Grizzly reported no such restriction (or they had never thought about it) and this did tip things in their favor.

The machine has done nothing but work flawlessly until this recent episode. I could use this as an excuse to upgrade to a 3HP but, I wouldn't want to release a possibly troubled machine into the wild.

[glenn bradley]

OK, opened her up and as expected the cap was blown just as before. I went through the diagnostic steps shown in the video; cap bad, switch functions, etc. I also used a meter and very carefully followed the physical path from termination point back as far as I could follow the insulated path looking for any signs of conductivity where it hadn't ought to be. All seems well. I still have a new cent-clutch assembly supplied back when I thought I had an issue when the machine was new. At first I thought the "new" clutch moved easier than the original one that is on the machine. I removed the original and once I had both clutches side by side I can see/feel that they both actuate the same. I should also mention that the motor turns quite easily. I can set it in motion with just my thumb and index finger giving the shaft a slight twist.

The machine has a longer startup time than any of my other machines including ones with larger motors. The cyclone does have to get that big ole impeller up to speed as opposed to, for example, my 15" planer that only needs to spin the smaller diameter cutterhead up to speed. At any rate it is not the long startup that seems to be an issue necessarily although I understand that the start-cap should only be in the circuit the prescribed amount of time. The noise prior to catastrophic cap failure is indicative of the start circuit being engaged longer than required.

It seems a properly sized bleed resistor will take a few seconds to bleed off any residual charge left at the point where the cap is removed from the circuit. The sparking makes me think residual charge could be part of the problem but, it could just be a symptom of normal operation as well. My gut says poor quality cap. I will research bleed resistors further and certainly welcome any input from anyone who has a constructive opinion. I'll get with Grizzly tomorrow but, simply replacing the blown part is NOT an option. I will expect some decisive diagnostic instruction that isolates and changes something. Unless they want to ship me a case of start-caps for free while we keep trying the next step . . . blam! . . . that ain't it . . . next step . . . blam! . . . that ain't it . . . next step . . . blam! . . . that ain't it . . . next step. No thanks ;).

[Curt Harms]

I think if it were me, I'd try a cap from another source. If Grizzly got a bad batch of caps, any replacements could be coming from the same flawed batch.

[glenn bradley]

It was disappointing (and this from someone who has always been very pleased with Grizzly tech support) to get an email that shows that my original email was not fully read. The recommendation is for a fix that the email clearly states does not exist. Also, the recommendation that I forklift the motor on a 3 year old machine did not go over well. I responded politely (anyone can have a bad day and just not feel like putting out the effort) and asked that the history of this problem be reviewed and that I would like a specific next step recommended. I repeated that I am more than willing to perform any tasks they may require. I am reasonably confident that the next response will be better.

[John Lanciani]

...I am reasonably confident that the next response will be better.

Why? It's a 3 year old consumer grade machine with a one year warranty. The advice to source a batter quality start cap is valid, but it may well be that the start winding is compromised which will ultimately be terminal.

[Mike Goetzke]

This machine has been a champ since January of 2009 when I installed it. In November of last year it blew a starter cap. I do cycle the thing often but, involved Grizzly tech support to be sure. The initial recommendation was to inspect the area around the centrifugal switch, clean contacts and assure proper adjustment, confirm proper power at the proper locations and then replace the starter cap.

I had marked the original factory position of everything back during install as the cent-switch squeaked and I wanted to fix that (which I did). Everything was in the same position it had been since installation. I inspected, confirmed and cleaned, installed the cap and promptly blew it up. Tech support had me dig in deeper and clean more aggressively. I put in the second cap and it ran great for about a month; it just blew again. I have notified Grizzly tech support again but, thought I would put this out to the community.

Power has been verified between lines and between each line and ground. I can find no ground fault at this time and power is as it should be. The cent-clutch moves properly and the switch mechanism move freely. When the cent switch opens there is a disconcerting sparking between the feed contact and the bracket that acts as the stop for the cent-switch when in the open position. This may be normal but, the sound that sparking makes is the same (or vary similar) sound heard repeatedly just before the cap blows. The sound goes for several seconds; long enough to be noticed but, too quick to allow me to get to the switch before the cap pops.

Don't want to hog your thread but I have another make cyclone and my cent-switch has a squeak. How did you eliminate it?

(I would also suggest looking for a cap from another supplier. I usually buy them from a heating & air conditioning shop near work.)

Thanks,

Mike

[glenn bradley]

Don't want to hog your thread but I have another make cyclone and my cent-switch has a squeak. How did you eliminate it?

Stupidly annoying, isn't it? :) The particular clutch on mine uses a plastic "mushroom" shaped plunger to move the contacts into the open/closed position. The surface of this plastic had a casting seam on it and this was oscillating the spring steel of the contact assembly. I placed some 600 grit sandpaper on the top of my tablesaw, placed the flat portion of the "mushroom" on it and moved it in a random pattern until I had a consistent scratch pattern. Cleaned it off real good and reassembled. No more squeak.

[John Lifer]

Do what others have said. Go source a new capacitor from Grainger or another local electrical contractor supply.
If it blows.. then you have an issue with the motor. Which I suspect is the issue due to you stating it takes the motor longer to get up to speed. The longer it takes the motor to spin up and kick the clutch out which cuts out the starter circuit, then the longer the capacitor is being energized and potentially damaged. That fan is NOT that hard to spin up, and I'd not compare to your planer head as being harder. If it 'twer me, I'd be saving up for replacement motor.

[Mike Goetzke]

Stupidly annoying, isn't it? :) The particular clutch on mine uses a plastic "mushroom" shaped plunger to move the contacts into the open/closed position. The surface of this plastic had a casting seam on it and this was oscillating the spring steel of the contact assembly. I placed some 600 grit sandpaper on the top of my tablesaw, placed the flat portion of the "mushroom" on it and moved it in a random pattern until I had a consistent scratch pattern. Cleaned it off real good and reassembled. No more squeak.

Thanks - I think I can get at mine by just removing the end cap of the motor, but, yeah at the end of the spin down...chirp...chirp...chirp


Mike

[glenn bradley]

Thanks - I think I can get at mine by just removing the end cap of the motor, but, yeah at the end of the spin down...chirp...chirp...chirp


Mike

Right, remove cap, remove fan, remove inner cap and remove clutch. Easier than it sounds. I was careful to mark the height and position of the clutch as you want to return it to the same height on the shaft when re-installing.

[Jim O'Dell]

Glenn, you say the motor takes longer to spin up than your other machines. Do you have a "feel" for if it takes longer to spin up than it did, say, 2 years ago? How many starts will a new cap work before it blows? The spark noise bothers me. You say you have a new centrifugal clutch assembly and that you had both off at one time. Did you put the new one back on or the original since they seemed to be the same? If the original, I'd at least try the new one since you already have it. Maybe talk to a motor rebuild shop, especially if you get your new cap there to see what they think.
What I've heard on cyclones and the start/stop cycle is no more than 6 times per hour. Not sure, but this may be why Bill Pentz recommends a compressor duty motor on his cyclone builds. If you're using a lot of air, there's no telling how many times an hour an air compressor would cycle. I try to get in the habit of if I'm making several cuts but have some down time for set up between cuts, to leave the cyclone on and just close the blast gates. Motor on the cyclone doing very little work, verified with amp meter, the noise is a lot lower, and you don't have the multiple on/off cycles. Anxious to see what your next step reveals!! Jim.