clarke compressor slow

[jackojacks]

Any Ideas please
iIhave a clarke air industrial 14cfm compressor .
i have to decompress it to start it the motor seems to be struggling to turn it over untill its hot so its turning over slowly therefore not making the air quickly today it would not keep up with my die grinder.

so pulled it out from under the bench it breaths its air from outside.
i removed the pully guard with the tank empty it turns over nice and freely whch i didnt expect really with the motor seeming to struggle to turn it over at the normal speed i expected it to be a bit stiff.
so does this sound like a motor problem ???
is there any way to check if its the motor and not the pump.
i have had it for prob 20yrs its normlly wired direct into a cooker socket and worked fine for years but got slower and slower the last couple of years.
Any ideas Thanks ...

 

[Woody.v8]

It sounds like a start/run capacitor problem.

 

[normspanners]

Here we go-------- first one of the cold weather compressor posts-------- read all the other posts-------- change the oil for starters !!

 

[jackojacks]

something i did notice the pully from the motor got hot after running for 1 to 2 miniutes which i thought was strange the pump pully was cold as you would expect

 

[jackojacks]

its not the weather its been doing it all summer plus its still mild here

 

[normspanners]

Change the oil and adjust the belt

 

[pondy]

something i did notice the pully from the motor got hot after running for 1 to 2 miniutes which i thought was strange the pump pully was cold as you would expect

Belt slipping maybe?

 

[normspanners]

Its still gettin a lot colder thats why you are posting now almost guarantee it, oils should be changed twice a year'ish coz it takes in moisture.

 

[daleyd]

Is the motor itself getting hot, transferring the heat to the pulley?

 

[normspanners]

Mine stalled out for the first time last week usually then thats my reminder to service it.

 

[rtbcomp]

+1 for belt tension. If the belt's been slipping it may be an idea to fit a new one.

 

[normspanners]

If the belt's been slipping it may be an idea to fit a new one.

deffo I agree slipping belts end up 'glazing' the belts sidewalls and you need to overtighten to get same amount of drive.
the problem is usually the oil gets a little thicker the cold makes it worse and it creates hard start up, then the belt slips and it creates a vicious circle.

 

[brightspark]

sounds daft but a slipping belt can overload the motor. it bites then it slips putting extra strain on motor when it grips

 

[jackojacks]

will change the oil belt tension seems fine. i dont think belt is slipping the motor is going slow (sounds like its going to stall till the pump gets hot) as if its not powerfull enough.
yes it is worse in the winter i do understand this from last winter but it struggled to start all summer i plumbed in a ball valve to enable me to de compress it to start it untill it had warmed up cos the screw in one was a pain to get back in when it was running.

 

[normspanners]

i dont think belt is slipping the motor is going slow

if its getting hot--------its slipping IMO. quite a lot of pumps make the belt slip at startup coz of the loading -----you just dont realize till you feel the pulley the slip only occurs on the last bit of the stroke at near max compression for a milli sec then when over tdc it grips changing the oil wont harm it if it dont fix it after all.

 

[normspanners]

the other thing that can cause a problem is the check valve leaking air, check the unloader in the pressure switch is piped to free air ? if air is leaking out there it is a sign the seat is damaged in the check valve.
As soon as the valve closes there is air coming both ways and it overloads the pump before the flywheel has built up inertia.

 

[jackojacks]

yes will change oil / check belt i dont think any air is leaking but will check . now its out in the open it going to have a good going over . i have been looking up the capaciters as mentioned earlier . will check them also (after unloading them first )
Thanks for the help so far

 

[normspanners]

Hope you sort it
Problem is a motor doesnt like being held back ----even 50 revs is hell for it, it wants/trys to be at 50 hz's and to be synchronous with and to match the mains any less rpm and it draws more amps then gets hot, the resistance increases it draws even more amps, gets hotter that causes more resistance, etc etc etc. All this doesn't do the cap any good either.

 

[jackojacks]

Cheers
me too ive got blasting to do lol
will let ya know when i get to the bottom of it

 

[chester dylan]

i had this problem with my clarke compresor and found that machine mart do a sae 30 compresor oil for cold conditions insted of the sae 40 this has sorted it out for me but 20 years old would could also meen new cap for the motor