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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

No. of carbon

wheel guard, the electrical cord and the

Wear limit brush

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. Replace the carbon

brush with a new one when it becomes worn

to its wear limit. Always keep carbon brushes

88

0.67" (17mm)

0.24" (6mm)

clean and ensure that they slide freely within

the brush holders.

Fig. 6

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. 88 indicated in Fig. 6.

Replacing carbon brushes:

 

 

<Disassembly>

 

 

(1) Loosen the D4 tapping screw retaining

 

 

the tail cover and remove the tail cover.

 

 

(2) Use the auxiliary hexagonal wrench or

 

Spring

small screwdriver to pull up the edge of

 

 

 

the spring that is holding down the carbon

Carbon Brush

Brush Holder

brush. Remove the edge of the spring

toward the outside of the brush holder.

 

Fig. 7

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Hitachi G 12SA2 instruction manual Maintenance and Inspection