Hitachi DH 25PB Maintenance and Inspection, Inspecting the drill bits, Inspecting the screws

English

MAINTENANCE AND INSPECTION

WARNING: Be sure to switch power OFF and disconnect the plug from the receptacle during maintenance and inspection.

1.Inspecting the drill bits

Since use of a dull tool will cause motor malfunctioning and degraded efficiency, replace the drill bit with a new one or resharpening without delay when abrasion is noted.

2.Inspecting the screws

Regularly inspect all screws and ensure that they are properly tightened. Should any of the screws be loosened, retighten them immediately.

WARNING: Using this rotary hammer with loosened screws is extremely dangerous.

3.Maintenance of the motor

The motor unit winding is the very “heart” of the power tool. Exercise due care to ensure the winding does not become damaged and/or wet with oil or water.

4.Inspecting the carbon brushes: (Fig. 18)

The motor employs carbon brushes which are consumable parts. When they become worn to or near “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 Nos. shown in the figure. In addition, always keep carbon brushes clean and ensure that they slide freely within the brush holders.

CAUTION:

Using this rotary hammer with a carbon brush which is worn in excess of the wear limit will damage the motor.

Wear limit

		a	No. of
			carbon brush
	Usual carbon	0.2"	21
	brush	(5 mm)
No. of carbon brush	Auto-stop	—	70
a	carbon brush
0.47"
(12 mm)

Fig. 18

NOTE: Use HITACHI carbon brush No. indicated in Fig. 18.

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