DeWalt D55166, Instruction Manual

English

5

COMPONENTS AND FEATURES (FIG. A–E)

WARNING: 

Never modify the power tool or any part 

of it. Damage or personal injury could result.

Refer to Figure A at the beginning of this manual for a 
complete list of components.

Specifications

MODEL

D55166

WEIGHT

59.5 lbs. (27 kg)

HEIGHT

23.23" (590 mm)

WIDTH

10.04" (255 mm)

LENGTH

22.44" (569.9 mm)

AIR TANK CAPACITY (GALLONS)

6 Gallon (22.7 liters)

APPROX CUT-IN PRESSURE

105 PSI (723.9 kPa)

APPROX CUT-OUT PRESSURE

135 PSI (930.7 kPa)

SCFM @ 90 PSI (620.5 kPa)

3.8

VOLTAGE

Single 120 V

MINUMUM BRANCH CIRCUIT 
REQUIREMENT

15 Amp

PUMP OIL CAPACITY

10.6 oz. (313.5 ml)

FUSE TYPE

TIME DELAY

REGULATED PRESSURE RATING 
(APPROXIMATE)

7-135 PSI

QUICK CONNECT (E) TYPE

1/4" (6.4 mm) INDUSTRIAL

DUTY CYCLE

5 min ON, 5 min OFF

READ This OWnER’s MAnUAl AnD sAFETY RUlEs 
BEFORE OPERATing YOUR UniT.

 Compare the 

illustrations with your unit to familiarize yourself with the 
location of various controls and adjustments. Save this 
manual for future reference.

On/Off Switch

Place this switch 

 1 

 in the ON position to provide automatic 

power to the pressure switch and OFF to remove power at 
the end of each use.

Pressure Switch

The pressure switch 

 9 

 automatically starts the motor when 

the air tank pressure drops below the factory set “cut-in” 
pressure. It stops the motor when the air tank pressure 
reaches the factory set “cut-out” pressure.

Pressure Release Valve

The pressure release valve located on the side of the 
pressure switch, is designed to automatically release 
compressed air from the compressor head and the outlet 
tube when the air compressor reaches cut-out pressure 
or is shut off. The pressure release valve allows the motor 
to restart freely. When the motor stops running, air will be 
heard escaping from this valve for a few seconds. No air 
should be heard leaking when the motor is running or after 
the unit reaches cut-out pressure.

Safety Valve

If the pressure switch does not shut off the air compressor at 
its “cut-out” pressure setting, the safety valve 

 7 

 will protect 

against high pressure by “popping out” at its factory set 
pressure (slightly higher than the pressure switch “cut-out” 
setting).

FIG. B

7

Check Valve

When the air compressor is operating, the check valve 

 6 

 is 

“open”, allowing compressed air to enter the air tank. When 
the air compressor reaches “cut-out” pressure, the check 
valve “closes”, allowing air pressure to remain inside the air 
tank.

Tank Pressure Gauge

The tank pressure gauge 

 2 

 indicates the reserve air 

pressure in the tank.

Regulated Pressure Gauge

The regulated pressure gauge 

 3 

 indicates the air pressure 

available at the outlet side of the regulator. This pressure is 
controlled by the regulator.

Regulator

The regulator 

 4 

 controls the air pressure shown on the 

outlet pressure gauge. Turn regulator knob clockwise 
to increase pressure and counterclockwise to decrease 
pressure.

FIG. C

1

4

2

5

6

3

Drain Valve

The drain valve 

 8 

 is located at the base of the air tank and 

is used to drain condensation at the end of each use. See 

Draining Air Tank

 under

Maintenance.