Clarke BEXT 300HV - Manual (Page 13)

Page 28 Clarke ® B EXT ® -100, 100H 150H, 300HV Operator's Manual
Maintenance Of The Motor
This machine has a vacuum motor that uses carbon
brushes. The carbon brushes in the motor must be
checked every three months, or every 500 hours of
operation, whichever comes first. If either of the brushes
is shorter than 3/8 inch, replace both of the carbon
brushes.
How To Check The Commutator And The Carbon
Brushes
WARNING: Electrical inspections must be made
by a person authorized to make
electrical repairs.
To check the commutator and the carbon brushes follow
this procedure:
1. Disconnect the power cord from the electrical outlet.
2. Empty both tanks.
3. Unlatch tanks from lower housing.
4. Lift the upper housing from the lower housing.
5. Disconnect the ground wire.
6. Remove the plastic motor cover.
7. Inspect the commutator. See figure 10. Take the
machine to a Clarke authorized repair location if you
see any of the following conditions:
a. Small holes in the surface of the commutator.
See "A" in figure 11.
b. Uneven color. Look for an even dark brown color.
Clean areas or very dark areas indicate a
problem.
See "B" in figure 11.
c. High mica. The mica insulation must be lower
than the commutator bars. See "C" in figure 11.
8. To check the carbon brush assemblies, remove the
two screws from the holding bracket.
9. Remove the brackets.
10. Remove the carbon brush assemblies.
11. Check the carbon brush assembly. Replace both
carbon brush assemblies if either carbon brush is
shorter than
3 /
8
inch. If either brush is shorter than ½
inch, order replacement brushes. Be ready to
replace both carbon brushes earlier than the normal
inspection time.
12. Put the motor brushes in position.
13. Using the two screws, install the bracket that holds
the carbon brushes.
14. Install the plastic motor cover.
15. Connect the ground wire.
16. Install the motor holding bracket.
17. Install the lower housing to the upper housing.
Figure 10
UNEVEN
GOOD
SMALL
HOLES
GOOD
GOOD HIGH MICA
C
A B
MAINTENANCE
IRREGULAR
EN BUEN
ESTADO
AGUJEROS
PEQUEÑOS
EN BUEN
ESTADO
EN BUEN
ESTADO
MICA ALTA
C
A B
INÉGAL
CORRECT
PETITS TROUS
CORRECT
CORRECT
MICA ÉLEVÉ
C
A B