# Coolant pump motor from lathe issue



## johnwell (Dec 21, 2014)

Hi,
hopefully in the right place ...
Today filled coolant tray and switched it on. (pump submerged) Pump "struggled" to get revs and I stopped it. Set the whole tray outside lathe and tried again after checking for any obstructions. Clear. Tried switch on again and "struggle". At that point I tried help along the motorshaft to the impeller, which helped and motor started running. Irregular though and sounded still struggling. Plastic impeller so I tried lifting pump out fluid and that made the motor run faster. at times...still irregular and bogging down when submerged again. Out of fluid till it run higher rpm and at some point back in it started pumping. Not a very steady flow and after 15 seconds or so the flow became less to a drip. Switched pump off. Tried helping pump again outside and it reallyy wanted that help but ran again, still struggle. At some point POP_POP (2 pops) and silence. I could help it along once again outside fluid but it will not start up without 'help'. Now it won't even do anything even when trying to help. Humming different at certain slow turns by me on the shaft.
Does this sound like a bad capacitor right from the start or a faulty motor and do these little motors need that capacitor while running all the time?
I describe best I could....I think 

(Note: before I tried coolant for the first time (new/used lathe) 1 wire was disconnected from feed to pump. Either there was an issue before or just chinese quality control...lol) 

Please help? )

John


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## Ulma Doctor (Dec 21, 2014)

johnwell said:


> Hi,
> At some point POP_POP (2 pops) and silence. I could help it along once again outside fluid but it will not start up without 'help'. Now it won't even do anything even when trying to help. Humming different at certain slow turns by me on the shaft.
> Does this sound like a bad capacitor right from the start or a faulty motor and do these little motors need that capacitor while running all the time?
> I describe best I could....I think
> ...



Hi John,
the pops were the sound of the capacitor burning out! you'll need a new one.

not knowing the general condition or type of motor you have leaves a lot to the imagination.
my guess at this point is that you have a faulty start capacitor , but there may be other issues.

depending on what type of motor you have,
 it may not need a capacitor to run ,but, may need one to start the motor.
OR may need 1 to start  AND 1 to run the motor.
 some small motors only need one cap for the start and run.

 Generally the start circuit is normally closed and is opened by means of a centrifugal switch when the motor gains sufficient speed.
 when the motor drops below the cut in point, the centrifugal switch closes and the start cap dumps it's charge into the start circuit, increasing the motors rotational force until sufficient rotor speed opens the start circuit.
 the capacitor is recharged from line supply and awaits the closing of the start circuit to actuate again.

the wire being disconnected is a little scary, do you have means of uploading and posting photo's?
that would make my job easier but not 100% necessary


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## johnwell (Dec 21, 2014)

Ulma Doctor said:


> Hi John,
> the pops were the sound of the capacitor burning out! you'll need a new one.
> 
> not knowing the general condition or type of motor you have leaves a lot to the imagination.
> ...



Hi Mike,
Thank you very much for your very quick response!
As far as I can see/understand there is not even room in the housing for a centrifugal switch, but I'm far from a motor expert. I opened the motor housing from the back only and all i was able to see is a stator and rotor. The capacitor is outside the  housing. It's just a small 120V single phase 0.3 amp motor.
You are right about the capacitor blown...my father in law just confirmed that too but he's more electronic-ish and not so much motor-ish..lol.
Before I bother you with too many things I'm calling tomorrow the dealer I just got the machine from and he (should) help me further with this. I do have warranty on it and this is the first time I even tried the coolant deal.
You'd think it's covered by warranty...I just tried to fix it myself if it was an easy one.
In any case I appreciate your quick response and hope if all goes south I can sorta count on you again for a possible solution....)))

Thanks again Mike!

John


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## Ulma Doctor (Dec 21, 2014)

no worries John!
send a PM if you need help or have questions.
mike)


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