Figure 7-21.Magnetic switch controlled by three start-stop stations.
Figure 7-22.Control circuit for three start-stop stations.
Figure 7-23.Control circuit for two start-stop stations.
Greasing Ball Bearings
Only a high grade of grease with the following
general characteristics should be used for ball-bearing
1. Consistency, a little stiffer than that of
petroleum jelly, maintained over the operating
2. Melting point preferably over 150°C
3. Freedom from separation of oil and soap under
operating and storage conditions
4. Freedom from abrasive matter, acid, and alkali
In greasing a motor, you must take care not to add
too much grease. Overgreasing will cause too high an
operating temperature with resulting expansion and
leaking of the grease, especially with large bearings
operated at slow speeds.
Always review the Material Safety Data Sheet
(MSDS) for greases, oils, lubricants, and other
hazardous materials before use. Avoid pro-
longed skin contact with lubricants. Dispose of
waste materials in an environmentally
The following procedures are recommended for
greasing ball-bearing motors equipped with a
pressure-relief greasing system.