Teco Installation and Maintenance Manual 
TEFC Squirrel Cage Induction Motors 
Teco Electric and Machinery Company 
Manual Number: IOM ~ TEFC Rev.01 
 
7.1.10.  Selection of grease gun. 
There are two types of grease gun. High pressure lever type and hand press 
type. As the hand press type has a lower force, grease replacement will 
take more time. Greasing can be achieved quickly by using a lever type gun, 
however, care should be taken to adjust the pressure and rate to avoid 
excessive grease entry which may enter the motor’s interior. 
 
7.2.  NOISE OF BEARING. 
a.  Normal noise. 
Noise is congenital to movement of the bearing. Generally bearing noise 
that has a continuous rhythm with no sudden change is normal. 
b.  Abnormal noise. 
It is difficult to detect the early stages of bearing failure with the human 
ear. It takes a lot of experience and a sharp ear to detect abnormal noise. 
Any sudden change in bearing noise should be investigated. Motors with 
roller bearings at the drive end can emit more rotational noise than a ball 
bearing and it is normal to hear skating/skidding of the rolling elements. 
 
7.3.  VIBRATION. 
If the vibration of the bearing is unusually high, please test with vibroscope.  
The preferred level for vibration should be below 2.8mm/sec. If the values 
exceed this figure, an investigation should be undertaken to find and rectify 
the problem.  
 
7.4.  REGULAR INSPECTION. 
 
7.4.1.  Regular monthly inspection. 
  Grease replenishment (refer to Section 7.1) and the motor lubrication plate.