User Manual for HiKOKI DH 12DD Cordless Rotary Hammer

Quick Guide

The HiKOKI DH 12DD is a cordless rotary hammer designed for drilling anchor holes, concrete, and tile, as well as drilling in steel or wood (with optional accessories) and tightening screws. Always ensure the battery is charged and the tool is in the OFF position before inserting the battery.

Safety Warnings

WARNING: Read all safety warnings and instructions. Failure to follow them may result in electric shock, fire, or serious injury. Always wear ear protection and use the auxiliary handle if supplied. Hold the tool by insulated gripping surfaces when performing operations where the cutting accessory may contact hidden wiring.

Names of Parts

Key components include the handle, switch trigger, change lever, depth gauge, drill bit, LED light, and battery. Refer to the diagrams in the manual (Fig. 1) for the exact location of these parts.

Mounting and Operation

Key operations include:

• Removing/Inserting Battery: Use the latch to remove or insert the battery.
• Charging: Connect the charger to a power source, insert the battery, and monitor the pilot lamp (Table 1).
• Installing/Removing Side Handle: Adjust as needed for better control.
• Inserting/Removing SDS-plus Tools: Clean the shank and pull on the bit to check latching.
• Selecting Operation Mode: Use the changeover switch to select rotation speed (Low/Normal) and auto stop mode.

Auto Stop Function

This function supports continuous drilling. It features a memory mode to store the work time from switch ON to switch OFF. From the second drilling onwards, the motor stops automatically if the work exceeds the stored time.

Reactive Force Control (RFC)

The RFC feature reduces jerking of the tool body if the bit is suddenly overburdened. If the motor stops due to RFC, release the switch, remove the cause of the overburden, and resume operation.

Protection Function

The tool has a built-in protection circuit. If the display lamp and indicator lamp flash, the unit has ceased operation due to an abnormality (e.g., high temperature or sudden overburdening). Verify the cause and take necessary steps to correct it.

Maintenance and Inspection

Regularly inspect the tool, mounting screws, and motor. Keep terminals clean of swarf and dust. Clean the outside with a soft dry cloth or soapy water. After drilling concrete, clean the battery installation compartment and battery with an air gun or dry cloth.

Troubleshooting

If the tool does not operate normally, check the following:

• Tool doesn't run: Check battery charge, ensure it is securely attached, and clean terminals of concrete dust.
• Tool suddenly stopped: Check for overburdening (RFC activated) or battery overheating.
• Tool bits fall off: Ensure the correct SDS-plus bit is used and properly latched.