Grinder motor compatibility?

Salem Straub

Salem Straub

Joined
Oct 20, 2008
Messages
5,547
I just scored this motor for free, slightly used in a mechanical contractor's rubbish heap. Why it was thrown away I do not know, but while less than absolutely perfect for the application, (open frame construction, odd drive shaft) it has most of the things I was looking for in a grinder motor. 3hp, 3ph, 220/440v, 1725 rpm etc. Here is a link to the exact motor on Baldor's website; anyone care to take a quick look and give me some thoughts on whether this motor would be compatible with a TECO FM50 3hp VFD? I have seen some dust proofing measures invented for the open frame motors on some shop built grinders, but this motor is rated for max 40 degrees Celcius operating temp. Will adding dust filters cause it to overheat? Will this motor handle inverter duty use?

http://www.baldor.com/products/deta...otors_Pump&winding=35WGT676&rating=40CMB-CONT

Thanks for looking, guys.
 
vorpalknives said:
Geez, guys, don't everybody answer all at once now...
Click to expand...

Might want to be patient, some people don't read the forums all night waiting to answer your questions. I know it's rough waiting 7 hours for free help though.

Your VFD should be fine, I figured that out by reading the specs.

None of the other tools in your shop come with tefc motors. You may see your motor's life expectancy go down over a tefc motor, but I doubt you'll see all that much increase filtering it. If you want totally enclosed then that's what you'll need to get.
 
If you don't run a tecf I think where you mount it will make more difference than any filter. Try to position it so nothing gets thrown towards it. Maybe a shield in frond of it. You can get a 2hp 3ph TEFC from Grizzly right now for about $120
 
Wow, Acrid, wake up on the wrong side of the bed today? I can't say that it's all that uncommon for a light remark to be taken too seriously here, though. So let me just illuminate my former post by saying that after coming back to check for any thoughts five hours later, I saw my first post buried at the bottom of the first page with no replies. There were obviously active people on the forum in the interrim, as many of the posts above mine were bumped there by replies. It seemed to me that perhaps my question was oddball or seemed too simple or something, so mainly to re-post before disappearing, I typed a remark which is actually a common figure of speech usually taken as a lightly or humorously meant reaction to silence. To the extent which I have chimed in around here, it was usually if I had something I felt might be helpful to offer in reply to someone's query, or to offer compliments on a nice blade or an achievement. I don't generally see it as "free help" if I type it. After all, I am no expert even in areas where I am fairly knowledgeable. Who am I to take such a grand view of my advice?
Anyway, I do sincerely appreciate what remarks you had to offer in addressing my question, and I think I will use this motor as you both think it will be okay and I do too. Geez, it's a free 3hp Baldor!
 
Perhaps I read the light-hearted humor incorrectly, it read like entitlement to me, my apologies for the mistake. It's all free - some folks just seem to expect a certain level of attention that no one guaranteed.
 
You are absolutely right sir, I just feared that I was mistaken as one of those people. I just enjoy reading all of your opinions to the extent that it by god is sometimes hard to wait! Although I really am a sucker for free stuff...:D
 
Hello Vorpal

Good score! I especially like the price.

A couple of people on this forum have started using the Teco FM50 VFD's with good success. A 3 hp one ought to be fine for your motor.

You might want to check the motor out with a DVM the way Rob Frink suggests in post #17 of this thread before trying to run it:

http://www.bladeforums.com/forums/showthread.php?t=621868&page=1


You may also want to have a look at the video linked to in post #22 since your motor is an "Open drip-proof" type and only has "rodent screens at both ends". As ib2v4u states, keeping the dust away is more effective than filtering. Whatever you do, do not block off the rodent screens or the motor will burn up. That motor was designed to be cooled by drawing in air from outside it's casing. I will have to ask our Motor R&D Manager to see if Toshiba offers rodent screens on their motors too.

VFD's cause short, microseconds-long voltage spikes to appear on top of the voltage applied to the motor. They are only visible on an oscilloscope. A DVM is too slow to pick these up. "Inverter Rated" motors have heavier duty (thicker) insulation on the windings so they can withstand these high-voltage spikes on an ongoing basis and give a reasonable working life. Your motor is not Inverter Rated but should still give you an acceptable working life since you are not likely to be using it as long as an industrial user would.

I just noticed that you live on the North East side of Oahu. Do you ever go to get shrimp from Giovanni's, further up the coast? We have fond memories of our trips to your beautiful state.

Phil
 
pso said:
Hello Vorpal

A couple of people on this forum have started using the Teco FM50 VFD's with good success. A 3 hp one ought to be fine for your motor.

You might want to check the motor out with a DVM the way Rob Frink suggests in post #17 of this thread before trying to run it:

http://www.bladeforums.com/forums/showthread.php?t=621868&page=1

You may also want to have a look at the video linked to in post #22 since your motor is an "Open drip-proof" type and only has "rodent screens at both ends". As ib2v4u states, keeping the dust away is more effective than filtering. Whatever you do, do not block off the rodent screens or the motor will burn up. That motor was designed to be cooled by drawing in air from outside it's casing. I will have to ask our Motor R&D Manager to see if Toshiba offers rodent screens on their motors too.

VFD's cause short, microseconds-long voltage spikes to appear on top of the voltage applied to the motor. They are only visible on an oscilloscope. A DVM is too slow to pick these up. "Inverter Rated" motors have heavier duty (thicker) insulation on the windings so they can withstand these high-voltage spikes on an ongoing basis and give a reasonable working life. Your motor is not Inverter Rated but should still give you an acceptable working life since you are not likely to be using it as long as an industrial user would.

I just noticed that you live on the North East side of Oahu. Do you ever go to get shrimp from Giovanni's, further up the coast? We have fond memories of our trips to your beautiful state.

Phil
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Alllllright, Phil, thank you for that very erudite response. Exactly what I was asking about. Giovanni's, do you mean one of those shrimp places up by Laie? One is all broken down, but another looks to be operating just fine. It has a sign proclaiming it's world famous shrimp. And they appear to farm them right beside the road in these ponds. Never did stop there, always was heading through to the north shore, going to see WAVES at Waimea or just lay in the sand! :cool:
 
Hello Vorpal

Glad to be able to help.

It's been quite a few years now since I went there. Laie looks like the right area. There were shrimp ponds by the shore. Giovanni's is on the inland side of the road and had what looked like a converted bread truck or airport shuttle bus with a bunch of awnings over picnic tables next to it. There were also quite a few cats sucking up for hand-outs. It's worth stopping by to get some lunch the next time you go that way. Their hot sauce was fabulous. Too bad they shut down their website cause I ran out.

Take care.

Phil
 
Yeah I'm pretty sure that place is still open; I'll have to check it out next time I'm up that way, thanks for the tip!
 
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