Maintenance And Inspection - Hitachi H 90SG Manual De Instrucciones

English
NOTE:
Sometimes the power tool does not begin the
striking stroke even when the motor rotates because
oil has become thick.
If the power tool is used at low temperatures or if it
is used after a long idle time, this demolition hammer
should be kept running in for about five minutes in
order to warm it up.

MAINTENANCE AND INSPECTION

WARNING:
Be sure to switch power OFF and disconnect the
plug from the receptacle during maintenance and
inspection.
1. Inspecting this demolition hammer
Since use of a dull accessory, such as a bull point, a
cutter, etc., will degrade efficiency and cause
possible motor malfunction, sharpen or replace with
a new one as soon as abrasion is noted.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loosened, retighten them immediately.
WARNING:
Using this demolition hammer with loosen screws
is extremely dangerous.
3. Inspecting the retainer (Fig. 3 and 4)
The retainer may become loose due to excessive use.
Always, pay attention to its proper functioning to
securely hold the accessory shank portion. If any
wear and tear is found, bring this demolition
hammer to an authorized service center for
maintenance service.
4. Inspecting the carbon brushes (Fig. 9)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "wear limit", it results 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 9.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush holders.
10
CAUTION:
After long time of use, the front cover becomes
hot.
Therefore, be careful not to burn your hands.
Wear limit
0.67" (17 mm)
NOTE:
Use HITACHI carbon brush No. 86 indicated in Fig. 9.
5. Replacing carbon brushes (Fig. 10)
Loosen the screws (Hexagon socket hd. bolt M6 ×
16) of the cap covers, then remove the housing
cover.
Loosen the screws (Hexagon socket hd. bolt M4 ×
10) of the cap covers, then remove the cap covers
(with cap rubber). After removing the brush caps,
the carbon brushes can be removed.
After replacing the carbon brushes, tighten the brush
caps, then mount the cap covers securely.
Housing Cover
No. of carbon brush
86
0.28" (7 mm)
Fig. 9
Hexagon Socket hd.
bolt M4×10
Cap cover
(with cap rubber)
Brush cap
Carbon brush
Brush holder
Hexagon Socket hd.
bolt M6×16
Fig. 10