Electric Motor Question

buddyb

The small exhaust fan in my shop has a problem that when that it is slow to start.Sometimes I have to give the blades a few turns before it will start,and then it runs fine.Any fix for that problem besides replacing the fan?

cbxjeff

Providing that you really have full voltage at the fan & there is no mechanical interference with the blades, I would remove the motor.  If it has oil or grease ports available try to lube it but I doubt that will do.  Best to replace the motor or depending on you installation, just replace the whole fan.

serf

Old age of windings or commutator? Sometimes a starter capacitor could be bad on a big electric motor fan.

                      serf

Beeramid

Give the bearings a shot of oil and see if it helps with starting.

nmyers

On inexpensive motors, the "oil port" is often just a stamped dimple in the shell; HVAC techs use the plastic oiler with a long, extendible spout.

Neal

Don McManus

I would try an air hose and blow it out. The accumulation of dust can restrict current through the brushes (if a permanent magnet motor this does not apply). Motors take roughly twice the amperage to start as they do to run.

if blowing it out doesn’t solve the problem, Grainger probably has a replacement in stock for cheap.

grdad45

Most small fan motors are called "shaded pole motors", I.E., no capacitor or brushes. If you can find an oil port, use a little light oil, and as was mentioned, a good cleaning is probably needed. 

4205raymond

Don McManus said:

I would try an air hose and blow it out. The accumulation of dust can restrict current through the brushes (if a permanent magnet motor this does not apply). Motors take roughly twice the amperage to start as they do to run.

if blowing it out doesn’t solve the problem, Grainger probably has a replacement in stock for cheap.

Agree here and sometimes if you can pull armature W/O too much trouble lock in drill and take some 1000 or 1500 paper and polish it slightly at brush contact area, blow off and hit it with acetone or something similar with a couple of swipes.---------------------------Ray

buddyb

Fixed it. Thanks for the advice.Pulled the fan down and blew it out and found oil holes on the motor.I took the blades off and put a drill on the motor shaft and spun the motor as I oiled it.Could hear the motor freeing up as the oil got to the bearings.

grdad45

buddyb said:

Fixed it. Thanks for the advice.Pulled the fan down and blew it out and found oil holes on the motor.I took the blades off and put a drill on the motor shaft and spun the motor as I oiled it.Could hear the motor freeing up as the oil got to the bearings.

Glad you got it going. We aren't good for a lot of things, but free advice is worth what you pay for it!