Compressor motor upgrade

[AllDodge]

80 Gal Kobalt 60 gal compressor and as presser builds up it starts slowing down. Haven't seen any smoke yet but I'm stating to smell something from the motor. Figure its time to replace it, its about 15 yrs old

AO Smith 5hp (3.7hprunning) 230V CCW 5/8 shaft 15 amps frame 56

Looking at a high hp motor or at least heavier duty

 

[foghorn1966]

Could be the centrifugal, switch or start capacitor, if this is a single phase motor. How long or how much pressure until it starts slowing down. More info needed to help point in right direction.

 

[AllDodge]

Starts slowing around 120 to 130 psi
Uses a start and run capacitor, and single phase

 

[timgunn1962]

Maybe a daft question: are you sure the motor is slowing down?

I've known compressor belts to slip a little and the pump runs audibly slower. The squeal you'd normally expect from slipping belts isn't audible above the general noise of the compressor. Hot belts can smell a lot like hot motors.

I stuck reflective tape on the motor pulley and pump flywheel pulley, found it was just the pump that slowed down and changed the belt and motor pulley. Job sorted.

If you have an optical tacho, it's an easy check.

 

[sberry]

I also say check the belt first.

 

[AllDodge]

I'll check but I'm not smell burnt rubber and watching the motor it does look to be slowing down, but will look closer

 

[sberry]

Reason we say this is,,,, it happens all the time. Tightened one a couple days ago, ran way better.

 

[AllDodge]

Your right guys thanks. I touched the screws holding the motor and couple were loose and the other 2 were not tight. All good now

 

[American Locomotive]

Just keep in mind that if the belt has been slipping that much, you may want to replace it with a new one. An overly worn belt can damage the pulleys (and vice versa).

 

[AllDodge]