Operation; Maintenance - DeWalt DC390 Instruction Manual

• NEVER attempt to connect 2 chargers together.
• The charger is designed to operate on standard household electrical power
(120 Volts). 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. Whenever 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 Tune-Up™ Mode.
4. Once the automatic Tune-Up™ Mode is complete the charger will transition to a mainte-
nance charge; the indicator light shuts off when the automatic Tune-Up™ Mode is complete.
SAVE THESE INSTRUCTIONS FOR FUTURE USE
Chargers
Your tool uses an 18 Volt D WALT Charger. Your battery can be charged in D
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Chargers, 15 Minute Chargers or Vehicular 12 volt charger. Be sure to read all safety
instructions before using your charger. Consult the chart on the back cover of this manual for
compatibility of chargers and battery packs.
Charging Procedure (Fig. 1)
DANGER: Electrocution hazard. 120 volts present at charging terminals. Do not probe with
conductive objects. Danger of electric shock or electrocution.
1. Plug the charger into an appropriate outlet before inserting battery pack.
2. Insert the battery pack into the charger. The red (charging) light will blink continuously
indicating that the charging process has started (Fig. 1).
3. The completion of charge will be indicated by the red light remaining ON continuously. The
pack is fully charged and may be used at this time or left in the charger.
Indicator Light Operation
Charge Indicators
Some chargers are designed to detect certain problems that can arise with battery packs.
Problems are indicated by the red light flashing at a fast rate. If this occurs, re-insert battery pack
into the charger. If the problem persists, try a different battery pack to determine if the charger is
OK. If the new pack charges correctly, then the original pack is defective and should be returned
to a service center or other collection site for recycling. If the new battery pack elicits the same
trouble indication as the original, have the charger tested at an authorized service center.
HOT/COLD PACK DELAY
Some chargers have a Hot/Cold Pack Delay feature: when the charger detects a battery that is
hot, it automatically starts a Hot Pack Delay, suspending charging until the battery has cooled.
After the battery has cooled, the charger automatically switches to the Pack Charging mode.
This feature ensures maximum battery life. The red light flashes long, then short while in the Hot
Pack Delay mode.
PROBLEM POWER LINE
Some chargers have a Problem Power Line indicator. When the charger is used with some
portable power sources such as generators or sources that convert DC to AC, the charger may
temporarily suspend operation, flashing the red light with two fast blinks followed by a
pause. This indicates the power source is out of limits.
LEAVING THE BATTERY PACK IN THE CHARGER
The charger and battery pack can be left connected with the red light glowing indefinitely. The
charger will keep the battery pack fresh and fully charged.
NOTE: A battery pack will slowly lose its charge when kept out of the charger. If the battery pack
has not been kept on maintenance charge, it may need to be recharged before use. A battery
pack may also slowly lose its charge if left in a charger that is not plugged into an appropriate
AC source.
WEAK BATTERY PACKS: Chargers can also detect a weak battery. Such batteries are still
usable but should not be expected to perform as much work. In such cases, about 10 seconds
after battery insertion, the charger will beep rapidly 8 times to indicate a weak battery condition.
The charger will then go on to charge the battery to the highest capacity possible.
Important Charging Notes
1. Longest life and best performance can be obtained if the battery pack is charged when the
air temperature is between 65°F and 75°F (18°- 24°C). DO NOT charge the battery pack in
an air temperature below +40°F (+4.5°C), or above +105°F (+40.5°C). This is important and
will prevent serious damage to the battery pack.
2. The charger and battery pack may become warm to touch while charging. This is a normal
condition, and does not indicate a problem.
3. If the battery pack does not charge properly:
a. Check current at receptacle by plugging in a lamp or other appliance
b. Check to see if receptacle is connected to a light switch which turns power off when you
turn out the lights.
c. Move charger and battery pack to a location where the surrounding air temperature is
approximately 65°F - 75°F (18° - 24°C).
d. If charging problems persist, take the tool, battery pack and charger to your local service
center.
4. The battery pack should be recharged when it fails to produce sufficient power on jobs which
were easily done previously. DO NOT CONTINUE to use under these conditions. Follow the
charging procedure. You may also charge a partially used pack whenever you desire with
no adverse affect on the battery pack.
5. Under certain conditions, with the charger plugged into the power supply, the exposed
charging contacts inside the charger can be shorted by foreign material. Foreign materials
of a conductive nature such as, but not limited to, steel wool, aluminum foil, or any buildup
of metallic particles should be kept away from charger cavities. Always unplug the charger
from the power supply when there is no battery pack in the cavity. Unplug charger before
attempting to clean.
6. Do not freeze or immerse charger in water or any other liquid.
WARNING: Shock hazard. Do not allow any liquid to get inside charger.
CAUTION: Never attempt to open the battery pack for any reason. If the plastic housing of
the battery pack breaks or cracks, return to a service center for recycling.
Installing and Removing the Battery Pack (Fig. 2, 3)
NOTE: Make sure your battery pack is fully charged.
CAUTION: Make certain the switch lock-off button (A) is engaged to prevent switch actuation
before removing or installing battery.
To install the battery pack into the tool handle, align the base of the tool with the notch inside
the tool's handle and slide the battery pack firmly into the handle until you hear the lock snap
into place.
To remove the battery pack from the tool, press the release buttons (M) and firmly pull
the battery pack out of the tool handle. Insert it into the charger as described in the charger
manual (Fig. 2).

OPERATION

Switch (Fig. 3)
Release switch lock-off button (A) by pressing button as shown (Fig. 3). Pull the trigger switch (B)
to turn the motor ON. Releasing the trigger switch turns the motor OFF. Releasing the trigger
switch also automatically actuates lock-off button.
NOTE: This tool has no provision to lock the switch in the ON position, and should never be
locked ON by any other means.
Changing Blades
CAUTION: TURN OFF TOOL AND REMOVE BATTERY PACK FROM SAW BEFORE
CHANGING ACCESSORIES OR MAKING ANY ADJUSTMENTS.
TO INSTALL THE BLADE (FIG. 4, 5)
1. Place inner clamp washer (N) on saw spindle with the large flat surface facing out toward
the blade (Fig. 4).
2. Retract the lower blade guard (G) and place blade on saw spindle against the inner clamp
washer, making sure that the blade will rotate in the proper direction (the direction of
the rotation arrow on the saw blade and the teeth must point in the same direction as the
direction of rotation arrow on the saw). Do not assume that the printing on the blade will
always be facing you when properly installed. When retracting the lower blade guard to install
the blade, check the condition and operation of the lower blade guard to assure that it is work-
ing properly. Make sure it moves freely and does not touch the blade or any other part, in all
angles and depths of cut.
3. Place outer clamp washer (O) on saw spindle with the large flat surface against the blade with
beveled side facing out.
4. Thread blade clamping screw (H) into saw spindle by hand (screw has left-hand threads and
must be turned counterclockwise to tighten).
5. Depress the blade lock (K) while turning the saw spindle with the blade wrench until the
blade lock engages and the blade stops rotating (Fig. 5).
6. Tighten the blade clamping screw firmly with the blade wrench.
NOTE: Never engage the blade lock while saw is running, or engage in an effort to stop the tool.
Never turn the saw on while the blade lock is engaged. Serious damage to your saw will result.
TO REPLACE THE BLADE (FIG. 5)
1. To loosen the blade clamping screw (H), depress the blade lock (K) and turn the saw spin-
dle with the blade wrench until the blade lock engages and the blade stops rotating. With the
blade lock engaged, turn the blade clamping screw clockwise with the blade wrench (screw
has left-hand threads and must be turned clockwise to loosen).
2. Remove the blade clamping screw (H) and outer clamp washer (O) only. Remove old blade.
3. Clean any sawdust that may have accumulated in the guard or clamp washer area and check
the condition and operation of the lower blade guard as previously outlined. Do not lubricate
this area.
4. Select the proper blade for the application (see Blades). Always use blades that are the cor-
rect size (diameter) with the proper size and shape center hole for mounting on the saw spin-
dle. Always assure that the maximum recommended speed (rpm) on the saw blade meets
or exceeds the speed (rpm) of the saw.
5. Follow steps 2 through 6 under To Install the Blade, making sure that the blade will rotate in
the proper direction.
LOWER BLADE GUARD
WARNING: The lower blade guard is a safety feature which reduces the risk of serious
personal injury. Never use the saw if the lower guard is missing, damaged, misassem-
bled or not working properly. Do not rely on the lower blade guard to protect you under
all circumstances. Your safety depends on following all warnings and precautions as well
as proper operation of the saw. Check lower guard for proper closing before each use as
outlined in Additional Safety Rules for Circular Saws. If the lower blade guard is missing
or not working properly, have the saw serviced before using. To assure product safety
and reliability, repair, maintenance and adjustment should be performed by an authorized
service center or other qualified service organization, always using identical replacement
parts.
Blades
WARNING: To minimize the risk of eye injury, always use eye protection. Carbide is a hard
but brittle material. Foreign objects in the work piece such as wire or nails can cause tips to
crack or break. Only operate saw when proper saw blade guard is in place. Mount blade secure-
ly in proper rotation before using, and always use a clean, sharp blade.
CAUTION: Do not cut ferrous metals (steel), masonry, glass or tile with this saw.
A dull blade will cause slow, inefficient cutting overload on the saw motor, excessive splinter-
ing, and could increase the possibility of kickback. Please refer to the table on next page to
determine the correct size replacement blade for your model saw.
Model Blade
DC390 DW9155
DW9154
DW9153
If you need assistance regarding blades, please call 1-800-4-D
Cutting Depth Adjustment (Fig. 6, 7)
CAUTION: TURN OFF TOOL AND REMOVE BATTERY PACK FROM SAW BEFORE
CHANGING ACCESSORIES OR MAKING ANY ADJUSTMENTS.
1. Hold the saw firmly and loosen(clockwise) the depth adjustment knob (D) and move shoe to
obtain the desired depth of cut.
2. Make sure the depth adjustment knob has been retightened (counterclockwise) before oper-
ating saw.
WALT 1 Hour
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For the most efficient cutting action, set the depth adjustment so that one tooth of the blade will
project below the material to be cut. This distance is from the tip of the tooth to the bottom of the
gullet in front of it. This keeps blade friction at a minimum, removes sawdust from the cut, results
in cooler, faster sawing and reduces the chance of kickback. A method for checking for correct
cutting depth is shown in Figure 7. Lay a piece of the material you plan to cut along the side of
the blade, as shown, and observe how much tooth projects beyond the material.
NOTE: When using carbide-tipped blades, make an exception to the above rule and allow only
one-half of a tooth to project below the material to be cut.
Bevel Angle Adjustment (Fig. 7)
CAUTION: TURN OFF TOOL AND REMOVE BATTERY PACK FROM SAW BEFORE
CHANGING ACCESSORIES OR MAKING ANY ADJUSTMENTS.
The full range of the bevel adjustment is from 0˚ to 50˚. The quadrant is graduated in increments
of 1˚. On the front of the saw is a bevel angle adjustment mechanism (Fig. 7) consisting of a cal-
ibrated quadrant and a knob (J).
TO SET THE SAW FOR A BEVEL CUT
1. Loosen (counterclockwise) the bevel adjustment knob (J) and tilt shoe to the desired angle
by aligning the pointer with the desired angle mark.
2. Retighten knob firmly (clockwise).
Shoe Adjustment for 90˚ Cuts
CAUTION: TURN OFF TOOL AND REMOVE BATTERY PACK FROM SAW BEFORE
CHANGING ACCESSORIES OR MAKING ANY ADJUSTMENTS.
IF ADDITIONAL ADJUSTMENT IS NEEDED
1. Adjust the saw to 0˚ bevel.
2. Retract blade guard. Place the saw on blade side.
3. Loosen bevel adjustment knob. Place a square against the blade and shoe to adjust the 90˚
setting.
4. Move the adjustment screw so that the shoe will stop at the proper angle.
5. Confirm the accuracy of the setting by checking the squareness of an actual cut on a scrap
piece of material.
Kerf Indicator
The front of the saw shoe has a kerf indicator for vertical and bevel cutting. This indicator
enables you to guide the saw along cutting lines penciled on the material being cut. The indi-
cator lines up with the left (outer) side of the saw blade, which makes the slot or "kerf" cut by
the moving blade fall to the right of the indicator. Guide along the penciled cutting line so that
the kerf falls into the waste or surplus material.
Work Piece Support (Fig. 8, 9, 10)
WARNING: It is important to support the work properly and to hold the saw firmly to prevent
loss of control which could cause personal injury. Figure 8 illustrates proper hand support of the
saw. Maintain a firm grip with both hands on the saw and position your body and arm to allow
you to resist kickback if it occurs. ALWAYS TURN OFF TOOL AND REMOVE BATTERY
BEFORE MAKING ANY ADJUSTMENTS!
Figure 8 shows proper sawing position. Note that hands are kept away from cutting area. To
avoid kickback, DO support board or panel NEAR the cut (Fig. 9). DON'T support board or
panel away from the cut (Fig. 10).
Place the work with its "good" side – the one on which appearance is most important – down.
The saw cuts upward, so any splintering will be on the work face that is up when you cut it.
Cutting
Place the wider portion of the saw shoe on that part of the work piece which is solidly support-
ed, not on the section that will fall off when the cut is made. As examples, Figure 8 illustrates
the RIGHT way to cut off the end of a board. Always clamp work. Don't try to hold short pieces
by hand! Remember to support cantilevered and overhanging material. Use caution when saw-
ing material from below.
Be sure saw is up to full speed before blade contacts material to be cut. Starting saw with blade
against material to be cut or pushed forward into kerf can result in kickback. Push the saw for-
ward at a speed which allows the blade to cut without laboring. Hardness and toughness can vary
even in the same piece of material, and knotty or damp sections can put a heavy load on the saw.
When this happens, push the saw more slowly, but hard enough to keep working without much
decrease in speed. Forcing the saw can cause rough cuts, inaccuracy, kickback, and over-heat-
ing of the motor. Should your cut begin to go off the line, don't try to force it back on. Release the
switch and allow blade to come to a complete stop. Then you can withdraw the saw, sight anew,
and start a new cut slightly inside the wrong one. In any event, withdraw the saw if you must shift
the cut. Forcing a correction inside the cut can stall the saw and lead to kickback.
IF SAW STALLS, RELEASE THE TRIGGER AND BACK THE SAW UNTIL IT IS LOOSE. BE
SURE BLADE IS STRAIGHT IN THE CUT AND CLEAR OF THE CUTTING EDGE BEFORE
RESTARTING.
As you finish a cut, release the trigger and allow the blade to stop before lifting the saw from the
work. As you lift the saw, the spring-tensioned telescoping guard will automatically close under
the blade. Remember the blade is exposed until this occurs. Never reach under the work for any
reason. When you have to retract the telescoping guard manually (as is necessary for starting
pocket cuts) always use the retracting lever.
NOTE: When cutting thin strips, be careful to ensure that small cutoff pieces don't hang up on
inside of lower guard.
RIPPING (FIG. 11)
Ripping is the process of cutting wider boards into narrower strips – cutting grain lengthwise.
Hand guiding is more difficult for this type of sawing and the use of a rip fence is recommended.
POCKET CUTTING (FIG. 12)
CAUTION: TURN OFF TOOL AND REMOVE BATTERY PACK FROM SAW BEFORE
CHANGING ACCESSORIES OR MAKING ANY ADJUSTMENTS.
CAUTION: Never tie the blade guard in a raised position. Never move the saw backwards
when pocket cutting. This may cause the unit to raise up off the work surface which could cause
injury.
A pocket cut is one that is made in a floor, wall, or other flat surface.
1. Adjust the saw shoe so the blade cuts at desired depth.
2. Tilt the saw forward and rest front of the shoe on material to be cut.
3. Using the retracting lever, retract lower blade guard to an upward position. Lower rear of
shoe until blade teeth almost touch cutting line.
4. Release the blade guard (its contact with the work will keep it in position to open freely as
you start the cut). Remove hand from guard lever and firmly grip auxilary handle, as shown
in Figure 12. Position your body and arm to allow you to resist kickback if it occurs.
5. Make sure blade is not in contact with cutting surface before starting saw.
6. Start the motor and gradually lower the saw until its shoe rests flat on the material to be cut.
Advance saw along the cutting line until cut is completed.
7. Release trigger and allow blade to stop completely before withdrawing the blade from the
material.
8. When starting each new cut, repeat as above.

MAINTENANCE

Cleaning
CAUTION: Never use solvents or other harsh chemicals for cleaning the non-metallic parts
of the tool. These chemicals may weaken the plastic materials used in these parts. Use a cloth
dampened only with water and mild soap. Do not use gasoline, turpentine, lacquer or paint thin-
ner, dry cleaning fluids or similar products. Never let any liquid get inside the tool; never immerse
any part of the tool into a liquid.
CHARGER CLEANING INSTRUCTIONS
WARNING: Shock hazard. Disconnect the charger from the AC outlet before cleaning. Dirt
and grease may be removed from the exterior of the charger using a cloth or soft non-metallic
brush. Do not use water or any cleaning solutions.
Lubrication
Self lubricating ball and roller bearings are used in the tool and relubrication is not required.
However, it is recommended that, once a year, you take or send the tool to a certified service cen-
ter for a thorough cleaning, inspection, and lubrication of the gear case.
Repairs
To assure product SAFETY and RELIABILITY, repairs, maintenance and adjustment (including
brush inspection and replacement) should be performed by a D
D WALT authorized service center or other qualified service personnel. Always use identical
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replacement parts.
Accessories
Recommended accessories for use with your tool are available at extra cost from your local
dealer or authorized service center. If you need assistance in locating any accessory for your
tool, please contact D
call 1-800-4-D WALT (1-800-433-9258) or visit our website www.dewalt.com.
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CAUTION: The use of any other accessory not recommended for use with this tool could be
hazardous.
Three Year Limited Warranty
D WALT will repair, without charge, any defects due to faulty materials or workmanship for three
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years from the date of purchase. This warranty does not cover part failure due to normal wear
or tool abuse. For further detail of warranty coverage and warranty repair information, visit
www.dewalt.com or call 1-800-4-D
accessories or damage caused where repairs have been made or attempted by others. This
warranty gives you specific legal rights and you may have other rights which vary in certain
states or provinces.
In addition to the warranty, D
D WALT will maintain the tool and replace worn parts caused by normal use, for free, any time
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during the first year after purchase.
If you are not completely satisfied with the performance of your D
Nailer for any reason, you can return it within 90 days from the date of purchase with a receipt
for a full refund – no questions asked.
LATIN AMERICA: This warranty does not apply to products sold in Latin America. For products
sold in Latin America, see country specific warranty information contained either in the packag-
ing, call the local company or see website for warranty information.
FREE WARNING LABEL REPLACEMENT: If your warning labels become illegible or are miss-
ing, call 1-800-4-D
Diameter Teeth Application
6-1/2" 18 General Purpose Cutting
6-1/2" 24 Smooth Wood Cutting
6-1/2" 90 Non-carbide, Plywood/
Vinyl Siding Cutting
WALT Industrial Tool Co., 701 East Joppa Road, Baltimore, MD 21286,
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WALT (1-800-433-9258). This warranty does not apply to
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WALT tools are covered by our:
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1 YEAR FREE SERVICE
2 YEARS FREE SERVICE ON XRP ™ BATTERY PACKS
DC9096, DC9091 and DC9071
90 DAY MONEY BACK GUARANTEE
WALT for a free replacement.
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WALT (1-800-433-9258).
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WALT factory service center, a
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WALT Power Tool, Laser, or
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