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Question
A 2 speed 220 volt cooler motor. doesn't start on low but does start on high. If i start on high then switch to low it runs. Is there 2 start capacitors or is there some other problem?

Answer
Sonny, There are specific multispeed motors that will ONLY start on the high speed.  They are rare and I doubt that is what you have, we really need current [amp] readings on both speeds,  that would tell us a lot, but likely you don't have a meter to measure the running currents?

Two speed motors could have two capacitors or one [shared].

You say this is a cooler motor,  but what type?  Is it the condenser motor, a blower motor, compressor motor?

Is it a cap start motor or a PSC [Permanent Split Capacitor]type motor?

There are many reasons the motor may not start on low,  

and those depend on the type of motor it is.

PSC motors tend to be "weak" on low, should start, but are more susceptible to mechanical issues, [worn bearings, housings, journals etc] also can be an electrical issue,  bad start switch etc.

Cap start motor, could be a dedicated cap per speed,  it just depends, they build motors in all types of configurations.

Is there a cap housing on the motor, or is the cap out in the open, maybe strapped to the motor?

If it is a PSC motor the rating on the cap will be very low, say 3 to 10 MFD and should be in a metal type can.

If it is a cap start motor, then it should have a hump or cover over a plastic type cap,  and the rating should be much higher  something like 300 to 600 MFD.

If you only have one cap,  the cheapest attempt to fix it is to replace the cap, whatever it is,  a weak cap [of any kind] might have enough "power" left to start the high speed, but not the low.

You ask if there are two caps, how many are there? Does there seem to be room for another cap? Like one is missing?

I need more info on what you have to help,  it could be anything from bearings to switches or wiring,   

If you have excessive movement in the motor shaft,   likely the bearings are going bad, and causing the weaker slow speed to not start at that option,   

Again if it has one cap, and there is no empty slot or position for another cap,  then replace the cap you have, and see if that fixes the problem.

If that doesn't do the trick, send me the complete nameplate info, along with a photo or two would be very helpful.  

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Three phase/ AC DC single phase motors, controls, any problems or failures, motor installation, performance issues, connections. All other electric motors/gearboxes/apparatus. Specialty repair concerns, obsolete motors and solutions. Other mechanical or specialty equipment. See my profile under Home/electrical at this site

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30 plus years in the electrical motor and apparatus repair industry. VP level management of repair facilities, current owner of my own specialty repair and consulting firm.

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EASA, IBEW [retired], other specialty organizations, Lubrication, Vibration EDI, Tribo-electric Councils

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Currently fielding concerns at this site under "Home Electrical"

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4 year technical, College level specific courses, EASA repair courses, vibration analysis electronic and electrical trade school.

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