DeWalt DC390 Instruction Manual page 10

• An extension cord must have adequate wire size (AWG
or American Wire Gauge) for safety. The smaller the gauge
number of the wire, the greater the capacity of the cable, that is
16 gauge has more capacity than 18 gauge. An undersized cord
will cause a drop in line voltage resulting in loss of power and
overheating. When using more than one extension to make up the
total length, be sure each individual extension contains at least
the minimum wire size. The following table shows the correct size
to use depending on cord length and nameplate ampere rating.
If in doubt, use the next heavier gauge. The smaller the gauge
number, the heavier the cord.
Recommended Minimum Wire Size for Extension Cords
Total Length of Cord
25 ft. 50 ft. 75 ft. 100 ft.
7.6 m 15.2 m 22.9 m 30.5 m 38.1 m 45.7 m 53.3 m
Wire Size AWG
18 18 16
• Do not place any object on top of charger or place the
charger on a soft surface that might block the ventilation
slots and result in excessive internal heat. Place the charger
in a position away from any heat source. The charger is ventilated
through slots in the top and the bottom of the housing.
• Do not operate charger with damaged cord or plug.
• Do not operate charger if it has received a sharp blow, been
dropped, or otherwise damaged in any way. Take it to an
authorized service center.
• Do not disassemble charger; take it to an authorized service
center when service or repair is required. Incorrect reassembly
may result in a risk of electric shock, electrocution or fire.
• Disconnect the charger from the outlet before attempting
any cleaning. This will reduce the risk of electric shock.
Removing the battery pack will not reduce this risk.
125 ft. 150 ft. 175 ft.
16 14 14 12
• NEVER attempt to connect 2 chargers together.
• The charger is designed to operate on standard 120V
household electrical power. Do not attempt to use it on any
other voltage. This does not apply to the vehicular charger.
Using Automatic Tune-Up™ Mode
The automatic Tune-Up™ Mode equalizes or balances the
individual cells in the battery pack allowing it to function at peak
capacity. Battery packs should be tuned up weekly or after
10 charge/discharge cycles or whenever the pack no longer delivers
the same amount of work. To use the automatic Tune-Up™, place
the battery pack in the charger and leave it for at least 8 hours. The
charger will cycle through the following modes.
1. The red light will blink continuously indicating that the 1-hour
charge cycle has started.
2. When the 1-hour charge cycle is complete, the light will stay on
continuously and will no longer blink. This indicates that the pack
is fully charged and can be used at this time.
3. If the pack is left in the charger after the initial 1-hour charge, the
charger will begin the Automatic Tune-Up™ mode. This mode
continues up to 8 hours or until the individual cells in the battery
pack are equalized. The battery pack is ready for use and can
be removed at any time during the Automatic Tune-Up™ mode.
4. Once the Automatic Tune-Up™ mode is complete, the charger will
begin a maintenance charge; the red indicator will remain lit.
Chargers
Your tool uses a D WALT 18 volt charger. Be sure to read all safety
E
instructions before using your charger. Consult the chart at the end
of this manual for compatibility of chargers and battery packs.
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