dead grizzly motor

[donald girod]

The 3hp motor on my 1023 Grizzly saw has crapped out. Starting switch and capacitor are ok, but the motor draws excessive current and snarls when it reaches running speed, and the overload on the motor switch kicks out. Sounds like a shorted winding somewhere, or a bad winding in any case, since all an induction motor has is a starting switch, a capacitor, and wire--gotta be the wire.

Is there any chance that getting the motor fixed (at least partially rewound) could be cheaper than a new motor (which goes for $250)? My impression is that these days rewinding is just for like 20 hp motors. Anybody got any experience along these lines?

[Edwin Pawlowski]

Why not see what a motor shop has to say? It could be overloading from bearing on the way out also. Worst case scenario is they put in on the bench and charge a few bucks to diagnose, best case is they fix it for just a few buck also. Ed

[Wilson Lamb]

[Rich]

[Michael R. Dow]

This might also be a good time to upgrade to a 5hp motor....

[donald girod]

I did all that--the bearings are perfect, the starting winding is perfect, the starting switch is perfect. The resistance is the same with the starting winding in or out--.8 ohms. There is no terminal block (this is single-voltage, non-reversable motor), so I can't check the windings independently without taking the motor apart, but I can check with the starting switch oper/closed. It starts right up, comes up to speed slowly (as you suggest), growls when running "at speed" but I don't think it ever reaches 3450, and blows the overload breaker in the motor switch after about

3 or 4 seconds--I would guess from the dimming lights that it is pulling a good 30 amps.

You are confirming my suspicion that you can't rewind a motor for $250, not if the outfit gets $50/hour and you have to pay for the copper wire.

Thanks for the reply.

[Roger Jensen]

Are you certain about the start switch? It sounds like it is hanging up and not switching to the run windings.

Rog

[donald girod]

Yes, I am certain. It pops open with a nice arc and a sput. AND, I checked the resistance between the windings and the motor frame (= saw frame, etc., lots of stuff to grab onto). .5 ohms!! The only thing saving me from CPR was the green wire and the bare wire all the way back to the panel. It had to be dumping about 20A into the circuit ground, and this is likely what blew the overload (after 5 seconds or so, plenty of time to die).

It is scary to think that an induction motor can just short the hot wire to ground on a whim. Every time you use equipment with this type of motor (any stationary tool, just about), you are depending on that ground. I don't know, maybe some equipment like this is double insulated but nothing that I have is. And if you put a GFCI on the circuit it is going to pop all the time. They often blow with electric motor loads, or so I have read. My only experience is our washing machine, which pops the GFCI about once a month.

I am getting a new motor. And 3hp is plenty for anything I do, as is $250.

[Larry Jaques]

On Sun, 26 Oct 2003 06:40:12 -0600, "Rich" brought forth from the murky depths:

The last time I checked motor rewinding costs was about 5 years ago. A place in Escondido, CA wanted $104 for a NEMA 56 1.5 (or

2hp?) motor. I don't imagine that the jump to 3hp would make a great difference, but time might.

If I were Donald, I'd check local rewinding prices. There are few people who still do it and some of those are retired (lowering the cost if they do it to keep busy.)

-------------------------------------------------- I survived the D.C. Blizzard of 2003 (from Oregon) ----------------------------

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[Larry Jaques]

On Sun, 26 Oct 2003 13:43:52 GMT, "Michael R. Dow" brought forth from the murky depths:

$69.99 gets him one at Harbor Freight right now. If nothing else, it could get him up and running until he had the other one rewound.

-------------------------------------------------- I survived the D.C. Blizzard of 2003 (from Oregon) ----------------------------

Comprehensive Website Development

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[Greg O]

Nope, ain't gonna work! I am pretty sure that Grizzly's cabinet saw motor is much like Delta's with the mounts welded on. If I am wrong, well never mind! Greg