Enco Mill - motor takes a few tries to get to full speed

Got the motor back on. Wired it up. Using the head crank to level the pulleys was a great idea.

Bad news: with new Caps, there is NO difference!

Motor starts spinning, but won’t go up to speed. Same as my original post to this thread. Seems to pulse at few hundred RPM.

It’s too cold now. Mabe later in the week, I will disconnect the belts to see if it’s related to the load on the motor.

Any other ideas?
 
Fifteen amps is about the limit of most 110/120 volt outlets- are you sure you are getting enough voltage to the motor?
Are you using a long and possibly thin extension cord?
Did this starting problem just happen recently? Or has it always started poorly?
mark
 
The problem has been happening since I've owned the mill. I just set it up last fall, so I don't have a lot of history with it. The outlet is in the garage. I have a 20A breaker feeding the garage, and it uses buried cable (3 wire, 12 gauge). I technically have two 20A lines going out there, one is just for lights. I'd estimate 50'-60' of buried cable.

Maybe I'm nuts, but it seems to be happening more frequently now that it's cold.
 
Hmmm does sound like the power is ok
There may be a bad winding in there- you say it does trip the breaker sometimes? That's a clue- the motor must have a fault since the power delivery seems adequate, even so, there is probably a sizeable voltage drop even with 12 ga wire
Running a motor of that horsepower on a 110 volt circuit is a losing proposition, the motor runs hotter, the switch contacts wear out sooner, larger gauge cables, etc. It may have been overheated before you got it. My rule is 240 volt for anything larger than 3/4hp
So it sounds like you might could get 240 out there using the existing wire, but you may need a new motor anyhow
 
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If you have an analog multimeter (needle type) try and measure the voltage at the mill when you power it on. Use clip on test leads or something similar so you can watch the meter while you flip the switch- I think there's still a good chance your power delivery is the culprit here
 
If it was me I would take another look at the centrifugal switch which connects the starting capacitor to the motor till its up to speed. Make sure you clean the contacts with a contact file or fine emery paper since appearance alone is deceiving. Also make sure the switch does not bind as it snaps on and off. Also, I would bring the motor inside , warm it up, and plug it into a dryer or stove 220v outlet to see if it spins up to full speed quickly; that would eliminate one possible problem right off the bat. Good luck.
 
When I pulled the cover off, I made sure the centrifugal switch was not bound up, and wasn't sticky. There was a bit of surface rust, probably from years of humid environments, but overall, it looked OK. The contacts looked very clean, again, nothing appeared to be sticking.

Can anyone comment on what happens to a motor when the centrifugal switch doesn't open? I've read that it ban burn up a starter cap, which is why I've been cautious. I did manage to trip the circuit breaker once by letting it "pulse" too long. (haven't tried that since - don't want to damage the motor.
 
Yes the cap and start winding can overheat if the centrifugal switch doesn't open. The "pulsing" behavior could be either a motor fault OR there is still too much voltage drop in your supply line.
Diecutter: His motor is running on 120 volts- lotsa current and a fairly long run of wire, sounds like a possible voltage drop situation or his motor is bad
 
markba633csi said:
Yes the cap and start winding can overheat if the centrifugal switch doesn't open. The "pulsing" behavior could be either a motor fault OR there is still too much voltage drop in your supply line.
Diecutter: His motor is running on 120 volts- lotsa current and a fairly long run of wire, sounds like a possible voltage drop situation or his motor is bad
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I agree. That's what I was trying to say (not very well) by suggesting he take the motor inside and hook it up near the main service panel at 120v, and also try 220v which would eliminate the long wire run to the shop. Just a suggestion since I'm not well versed in motors.
 
Sounds like a reasonable thing to try. It’s negative 10 here now, I may wait a few days...
 
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