Hitachi G 18SR Grinder User Manual


 
English
15
MAINTENANCE AND INSPECTION
WARNING: Be sure to switch power OFF and disconnect the plug from the receptacle
during maintenance and inspection.
Using cracked, deformed or damaged wheels can lead to wheel
breakage and resulting serious injury.
1. Replacing the depressed center wheel
Replace the depressed center wheel when it has been worn out to about 2-3/8" (60mm)
in external diameter. Confirm that there is no crack or any damage to the depressed
center wheel. If there is a crack or a transformation in the wheel, replace it immediately.
2. Inspecting the screws
Regularly inspect all screws and ensure that they are fully tightened. Should any of the
screws be loosened, retighten them immediately.
WARNING: Using this grinder with loosened screws is extremely dangerous.
3. Confirm that there is no damage in the wheel guard, the electrical cord and the
housing, etc.
Check that the on/off switch operates normally.
4. Inspecting the carbon brushes (Fig. 6)
The Motor employs carbon brushes which are consumable parts. When they become
worn to or near the “wear limit”, it could result in motor trouble. When an auto-stop
carbon brush is equipped, the motor will stop automatically. At that time, replace both
carbon brushes with new ones which have the same carbon brush Numbers shown in
the figure. In addition, always keep carbon brushes clean and ensure that they slide freely
within the brush holders.
CAUTION: Using this grinder with a carbon brush which is worn in excess of the wear
limit will damage the motor.
NOTE: Use HITACHI carbon brush No. 44 or 74 indicated in Fig. 6.
a
No. of
carbon brush
Usual carbon 0.24"
44
brush (6 mm)
Auto-stop 0.28"
74
carbon brush (7 mm)
Fig. 6
Wear limit
No. of carbon brush
0.67"
(17 mm)
a