Huawei WR 22SA manual Maintenance and Inspection

English

before further wear developes. Matching socket and bolt sizes are shown in Table 1.

The numerical value of a socket designation denotes the side to side distance (S) of its hex hole.

5.Holding the tool

Hold the Impact Wrench firmly with both hands by the body handle and the side handle. In this case hold the wrench in line with the bolt.

It is not necessary to push the wrench very hard. Hold the wrench with a force just sufficient to counteract the impact force.

6.Confirm the tightening torque

The following factors contribute to a reduction of the tightening torque. So confirm the actual

tightening torque needed by screwing up some bolts before the job with a hand torque wrench. Factors affecting the tightening torque are as follows.

(1)Line voltage:

The tightening torque decreases when the line voltage becomes low (See Fig. 4).

(2)Operating time:

The tightening torque increases when the operating time increases. But the tightening torque does not increase above a certain value even if the tool is driven for a long time (See Fig. 4).

(3)Diameter of bolt:

The tightening torque differs with the diameter of the bolt as shown in Fig. 4. Generally a larger diameter bolt has a larger tightening torque.

(4)Tightening conditions:

The tightening torque differs according to the torque ratio; class, and length of bolts even when bolts with the same size threads are used. The tightening torque also differs according to the condition of the surface of metal through which the bolts are to be tightened.

(5)Using optional parts:

The tightening torque is reduced a little when an extension bar, universal joint or a long socket is used.

(6)Clearance of the socket:

A worn or deformed hex or a square-holed socket will not give an adequate tightness to the fitting between the nut or anvil, consequently resulting in loss of tightening torque.

Using an improper socket which does not match to the bolt will result in an insufficient tightening torque. Matching socket and bolt sizes are shown in Table 1.

MAINTENANCE AND INSPECTION

1.Inspecting the socket

A worn or deformed hex or a square-holed socket will not give an adequate tightness to the fitting between the nut or anvil, consequently resulting in loss of tightening torque. Pay attention to wear of socket holes periodically, and replace with a new one if needed.

2.Inspecting the mounting screws

Regularly inspect all mounting screws and ensure that they are properly tightened. Should any of the screws be loose, retighten them immediately. Failure to do so could result in serious hazard.

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

For your continued safety and electrical shock protection, carbon brush inspection and replacement on this tool should ONLY be performed by a Hitachi Authorized Service Center.

5.Replacing supply cord

If the supply cord of Tool is damaged, the Tool must be returned to Hitachi Authorized Service Center for the cord to be replaced.

6.Service parts list

A:Item No.

B:Code No.

C:No. Used

D:Remarks

CAUTION

Repair, modification and inspection of Hitachi Power Tools must be carried out by a Hitachi Authorized Service Center.

This Parts List will be helpful if presented with the tool to the Hitachi Authorized Service Center when requesting repair or other maintenance.

In the operation and maintenance of power tools, the safety regulations and standards prescribed in each country must be observed.

MODIFICATION

Hitachi Power Tools are constantly being improved and modified to incorporate the latest technological advancements.

Accordingly, some parts (i.e. code numbers and/or design) may be changed without prior notice.

NOTE

Due to HITACHI’s continuing program of research and development, the specifications herein are subject to change without prior notice.

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