8 hp electric motor

[geok]

I recently bought a pump stuck snap-on 80 gal compressor that has a 8hp 230v 1 phase Baldor motor on it. Took belts off and turned on the motor to test it. Starts right up and turns strong. When the motor is turned off it coast for about 3 to 5 seconds then it acts like a brake comes on and stop the motor. Is this normal?

 

[JMOR]

(quoted from post at 10:00:47 08/04/22) I recently bought a pump stuck snap-on 80 gal compressor that has a 8hp 230v 1 phase Baldor motor on it. Took belts off and turned on the motor to test it. Starts right up and turns strong. When the motor is turned off it coast for about 3 to 5 seconds then it acts like a brake comes on and stop the motor. Is this normal?

otor type? Repulsion start/ induction run?

 

[geok]

 

[JMOR]

Unless buried in a code, I do not see any indication of start method.

 

[wore out]

''a brake comes on and stop the motor. Is this normal? ''

Yes.

When the motor slows down enough for the ''governor weight''-operated start switch to engage the start circuit that's the effect.

 

[geok]

Thank you. That is a relief. I went ahead and changed the pulley side bearing since it showed 2400 hrs on it. Getting the LP piston out of the
block took about 20 tons of push to get it to move.

 

[kencombs]

Every 3450/3600RPM compressor I've seen had start capacitors, some have run caps too. Cap-less high speed compressor motors may exist, but not in my world. but 8HP, 213 frame 3450rpm is a rare combination.

 

[JMOR]

Well, Ken, I haven't seen everything (just most). The reason I asked is that I have a 1927 compressor that uses repulsion start/induction run motor and when slowing, the centrifugal mechanism that held the commutator brushes away during run, after starting, will let them drop back onto commutator and slow it down more quickly. That's all folks!

 

[kencombs]

I have one of those. But it is only a 1HP original on my 1940something Unisaw. When I got it, I also bought a 3hp 240v/3ph to replace it. But, that little 1hp does everything I need.

Every one of the R/I motors on woodworking equipment that I've encountered were 1725rpm. That's why I left them out of my post.

On the other hand, every later cap start motor used on woodworking stuff has been 3450.

 

[miangus]

Perhaps it is a repulsion start single phase. When they spinn down the centrifugal clutch drops the start winding brushes on to the armature. They used start winding no caps. They use a lot of amps starting.