Atlas Copco FD450 User manual

Atlas Copco Air Dryers
Important:
This book applies exclusively to FD dryers as from following serial numbers onwards and filled with
refrigerant R404a; see data plate:
FD260: AIQ-124 045
FD300: AIQ-140 200
FD380: AIQ-129 800
FD450: AIQ-140 550
FD700: AIQ-750 005
*2920135101*
No. 2920 1351 01
Registration code: APC FD / 38 / 988
Replaces No. 2920 1351 00 and for FD700 only 2920 1371 00
1998-03
FD(W)260, -300, -380, -450, -700
Instruction Book
This instruction book meets the requirements for instructions specified by the machinery
directive 89/392/EEC and is valid for CE as well as non-CE labelled machines

2920 1351 01
2
Instruction book
This instruction book describes how to handle and operate the subject machine(s) to ensure safe operation, optimum working
economy and long service life.
Read this book before putting the machine into operation to ensure correct handling, operation and proper maintenance from
the beginning. The maintenance schedule contains a summary of the measures for keeping the dryer in good repair. The
maintenance procedures are simple but must be carried out regularly.
Keep the book available for the operator(s) and make sure that the dryer is operated and that the maintenance actions are carried
out according to the instructions. Record all operating data, maintenance work effected, etc. in an operator's logbook available
from Atlas Copco. Follow all applicable safety precautions, amongst others those mentioned on the cover of this book.
Repair operations must be performed by trained personnel from Atlas Copco, who can also be contacted if any further information
is desired.
In all correspondence always mention the dryer type and the complete serial number, shown on the data plate.
For all specific data not mentioned in the text, consult section "Principal data".
The company reserves the right to make changes without prior notice.
Contents
Page
1 Leading particulars . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 General description. . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Air circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Refrigeration circuit . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Automatic regulationsystem . . . . . . . . . . . . . . . . . 8
1.5 Electrical system . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Dimension drawings . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Installation proposal . . . . . . . . . . . . . . . . . . . . . . . 13
2.3 Installation instructions. . . . . . . . . . . . . . . . . . . . . 13
2.4 Pictographs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3 Operating instructions . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 Initial start. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3 During operation . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Page
3.4 Stopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.5 Possible causes of unstable or too high pressure
dewpoint temperature . . . . . . . . . . . . . . . . . . . . . . 16
4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1 Automatic expansion valve. . . . . . . . . . . . . . . . . . 17
5.2 Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Problem solving. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7 Principal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.1 Limitations/nominal conditions . . . . . . . . . . . . . . 19
7.2 Specific data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8 Conversion list of SI units into British/US units . . . 20

2920 1351 01 3
Instruction book
1 LEADING PARTICULARS
1.1 General description
The FD air dryers remove moisture from compressed air by
cooling the air to near freezing point. This causes water and
oil to condense. The condensate is automatically drained. The
air is warmed up before leaving the dryer.
On air-cooled dryers, the condenser has a cooling fan controlled
by a condenser pressure switch. Water-cooled dryers have an
automatic regulating valve in the water outlet of the condenser.
FD260 up to -700 are air-cooled, while FD260 W up to -700
W are water-cooled dryers. The suffix W is not mentioned
further in the book where the descriptions are valid for both
air- and water-cooled dryers.
1.2 Air circuit (Fig. 2)
Compressed air enters air/air heat exchanger (14) and is pre-
cooled by the outgoing, cold, dried air. Water and oil in the
incoming air start to condense. The air then flows through air/
refrigerantheat exchanger/evaporator(15) wherethe refrigerant
evaporates and withdraws heat from the air. This cools the air
to close to the evaporating temperature of the refrigerant. More
water and oil in the air condense. The cold air then flows
through separator (3) where all the condensate is separated from
the air. The condensate collects in condensate trap (4) and is
automatically drained. From separator (3) the cold dried air
flows through air/air heat exchanger (14), where it is warmed
up by the incoming air to approx. 10°C (18°F) below the
incoming air temperature. Reheating the dried air reduces its
relative humidity, so that condensation in the air net cannot
occur unless the air is cooled to below the pressure dewpoint
temperature indicated by gauge (1).
Fig. 1. Front view of FD450
F6837

2920 1351 01
4
Instruction book
AI. Air inlet connection
AO. Air outlet connection
M1. Refrigerant compressor/motor
M2. Condenser cooling fan motor
S2. High pressure shut-down switch
S3. Fan control switch
1. Pressure dewpoint temperature
gauge
2. Insulating block
3. Cyclone condensate separator
4. Condensate trap with automatic
discharge
5. Automatic condensate drain hose
6. Manual condensate drain valve
7. Liquid separator
8. Fan
9. Refrigerant condenser
10. Liquid refrigerant receiver
11. Refrigerant shut-off valve
12. Liquid refrigerant dryer/filter
13. Refrigerant expansion valve
14. Air/air heat exchanger
15. Air/refrigerant heat exchanger/
evaporator
Fig. 2. Air and refrigerant flow diagram, air-cooled dryers

2920 1351 01 5
Instruction book
1.3 Refrigeration circuit (Fig. 2)
Compressor (M1) delivers hot, high-pressure refrigerant gas,
which flows, via the coil of liquid separator (7), through
condenser (9) where most of the refrigerant condenses. On
air-cooled condensers, a fan control switch (S3) stops and starts
the fan motor (M2) at falling or rising condenser pressure. On
water-cooled condensers, an automatic valve (3-Figs. 5)
regulates the cooling water flow, thus controlling the
temperature, which is directly dependent on the pressure. The
cooled refrigerant then collects in receiver (10).
The liquid leaves the receiver (10) via its syphon outlet and
flows through liquid refrigerant filter/dryer (12) to expansion
valve (13) where it expands to evaporating pressure.
Inexpansion valve (13) some of the expanding liquid refrigerant
evaporates, for which the required heat is withdrawn from the
refrigerant itself.
Therefrigerant enters the heat exchanger/evaporator (15) where
it withdraws heat from the compressed air by further
evaporation. Dependent on the compressed air load, all, or
almost all, refrigerant evaporates at constant pressure and
temperature. The vapour refrigerant leaving evaporator (15)
flows into liquid separator (7). The liquid separator prevents
any droplets from entering compressor (M1) because warm
refrigerant, leaving the compressor, flows through the coil of
the liquid separator and evaporates the surrounding liquid.
From liquid separator (7) the refrigerant gas is sucked in by the
compressor.
F1. Fuses, fan motor
F2. Fuse, secondary side (24 V) of transformer
K1. Motor contactor, refrigerant compressor
K2. Motor contactor, condenser cooling fan
L1/3. Terminal, mains
PE. Earth terminal
T1. Transformer
1X1. Terminal strip
Fig. 3. Electric cubicle of FD260
T1 L1 L2 L3 1X1 PE
F2

2920 1351 01
6
Instruction book
Fig. 4a
Fig. 4b
M1. Refrigerant compressor/motor
M2. Condenser cooling fan motor
S2. High pressure shut-down switch
S3. Fan control switch
1. Condensate trap with automatic
discharge
2. Refrigerant shut-off valve
3. Condenser
4. Liquid refrigerant receiver
5. Fan
6. Refrigerant dryer/filter
7. Refrigerant expansion valve
8. Liquid separator
9. Electric cubicle
Figs. 4. Side views of FD450
3
5
M2
6
9
S3 S2 2 7
F6839

2920 1351 01 7
Instruction book
Fig. 5a
Fig. 5b
M1. Refrigerant compressor/motor
S2. High pressure shut-down switch
1. Liquid refrigerant receiver
2. Condenser
3. Flow regulating valve
4. Refrigerant shut-off valve
5. Electric cubicle
6. Condensate trap with automatic
discharge
7. Refrigerant shut-off valve
8. Refrigerant dryer/filter
9. Refrigerant expansion valve
10. Liquid separator
Figs. 5. Side views of FD380 W
F6841

2920 1351 01
8
Instruction book
1.4 Automatic regulation system (Fig. 2)
Expansion valve (13) maintains the evaporating temperature
between 1 and -1°C (34 and 30°F); these are the approximate
limit temperatures at zero and maximum air load respectively.
At partial or no load, the excess cooling capacity is transferred
in liquid separator (7). The condenser pressure must be kept
as constant as possible to obtain stable operation of expansion
valve (13). Therefore, on air-cooled dryers, fan control switch
(S3) stops and starts cooling fan (M2). On water-cooled dryers,
the temperature is controlled by an automatic regulating valve
on the water circuit. The switch or regulating valve ensures
properoperation at lowair load and/or low ambient temperature.
1.5 Electrical system
These dryers are three-phase units.
The refrigerant compressors are equipped with a crankcase
heater. When voltage is supplied, the heater is energized. It
keeps the oil in the crankcase warm to prevent condensing of
refrigerant in the compressor housing, which could result in
serious damage of the compressor at restart (liquid knock).
On air-cooled dryers, fan control switch (S3-Fig. 4b) will start
fan motor (M2-Fig. 4b) via contactor (K2-Fig. 3) as soon as
the condenser pressure reaches the upper set point of the switch
and will stop the fan motor when the condenser pressure
decreases to its lower set point.
High pressure shut-down switch (S2-Figs. 4b and 5b) stops the
compressor motor when the pressure in the refrigerant circuit
reachesthe upper set point of the switch. The compressor motor
will automatically restart when the pressure drops to the lower
set point.
Themotors have abuilt-in thermic protection. If the compressor
motor stops without apparent reason, it will most probably be
the thermic protection which has tripped. In such case, the
compressor will restart when the motor windings have cooled
down, which may take up to 2 hours.
An electronic dewpoint indicator with display and alarm
functions is installed on the instrument panel (Fig. 10). Display
(3-Fig. 12) shows the pressure dewpoint temperature. The set
point value, i.e. the pressure dewpoint temperature at which
the alarm indicator lamp (H3-Fig. 10) lights up, can be checked
by pressing key (5-Fig. 12); the value will blink for 5 seconds
on the display. The differential value (dT), i.e. the temperature
difference between alarm on and alarm off, can be checked by
pressing key (4-Fig. 12); the value will blink on the display for
approx. 5 seconds.
Altering the set point value (indicated "L1"):
- Press key (5); the current value blinks on the display.
- Press the up (1) or down (2) key until the desired value is
reached.
- To store the new value, press key (5) or wait a few seconds.
Altering the differential value (indicated "HY1"):
- Press key (4); the current value blinks on the display.
- Press the up (1) or down (2) key until the desired value is
reached.
- Press key (5) or wait a few seconds to store the new value.
If the temperature increases above the preset value, alarm
indicator lamp (H3-Fig. 10) will light up.
An automatic interval drain 1) may be connected between
condensate trap (4-Fig. 2) and manual drain valve (6-Fig. 2) to
flush the trap regularly. The interval time and opening time
can be adjusted.
2 INSTALLATION
2.1 Dimension drawings (Figs. 6)
See pages 9 up to 12
1) Optional equipment.

2920 1351 01 9
Instruction book
Fig. 6a. Dimension drawing of FD260 up to FD380 50/60 Hz and FD450 50 Hz

2920 1351 01
10
Instruction book
Fig. 6b. Dimension drawing of FD260 W up to FD380 W 50/60 Hz and FD450 W 50 Hz

2920 1351 01 11
Instruction book
Fig. 6c. Dimension drawing of FD700 50/60 Hz

2920 1351 01
12
Instruction book
Fig. 6d. Dimension drawing of FD700 W 50/60 Hz

2920 1351 01 13
Instruction book
2.2 Installation proposal (Fig. 7)
4. A sticker dealing in short with the operating instructions
and explaining the pictographs is delivered with the
literature set. Affix the sticker next to the control panel.
Makeyourself familiar with the instructions and pictographs
explained.
5. On water-cooled dryers, connect the water cooling pipes to
the marked in and out connections. It is recommended to
fit a manual shut-off valve in the water inlet.
6. Remove all the bags with silica gel attached to the dryer.
7. Check that the primary side connection of the transformer
(T1-Fig. 3) corresponds with the supply voltage.
8. Check that the electrical installation corresponds to the local
codes. The dryer must be earthed and protected against
short circuits by fuses of the inert type in all phases. An
isolating switch must be installed near the dryer. Connect 3
cables from the main fuses to terminals (L1, L2 and L3-
Fig. 3), connect the earth cable to the earth terminal (PE-
Fig. 3).
2.3 Installation instructions
1. Install the dryer where the ambient air is as clean as possible
and where the temperature of the air will never exceed or
drop below the temperature limits (see section 7). Keep
the ventilation gratings of the dryer free.
2. Connect the compressed air lines to the marked inlet and
outlet pipes of the dryer; if required, via valves and
preferably a by-pass valve. Apply a sealing medium to the
threaded connections.
3. Fit manual condensate drain valve (2-Fig. 8) onto the
condensate drain pipe.
Lay out the condensate drain hose (3-Fig. 8) via a funnel
towards a drain collector to allow visual inspection. The
hose must pitch downwards, away from the dryer and the
open end must never dip into the water of the drain collector.
If the condensate drain has been led down outside the
compressorroom where the pipe may be exposed to freezing
temperatures, the pipe must be insulated.
1. FD dryer
2a. DD-type general-purpose prefilter
2b. PD-type high-efficiency prefilter
2c. DD-type afterfilter
3. Air receiver with condensate drain
4. Pressure gauge
5. Drain pipes
6. Dryer outlet valve
7. By-pass system
8. By-pass valve
9. Dryer inlet valve
Fig. 7. Installation proposal

2920 1351 01
14
Instruction book
2.4 Pictographs (Fig. 9)
AI. Air inlet connection
AO. Air outlet connection
1. Cable gland
2. Manual condensate drain
3. Automatic condensate drain
4. Water inlet, condenser
5. Water outlet, condenser
6. Insulating block with heat exchangers
Fig. 8. FD380 W
1. Switch off and depressurize the dryer before
starting maintenance or repairs
2. Manual condensate drain
3. Automatic condensate drain
4. Pressure dewpoint
5. Dryer on-off
6. Voltage on
7. Dewpoint alarm
Fig. 9. Pictographs

2920 1351 01 15
Instruction book
3 OPERATING INSTRUCTIONS
Safety precautions
The operator must apply all relevant safety precautions,
including those mentioned in this book.
Altitude operation
Consult Atlas Copco if operating above 3000 m.
Moving/lifting
The dryer can be moved by a lift truck using the slot in the
frame. Make sure that the forks protrude from the other side of
the frame. The dryer can also be lifted after inserting beams in
the slot. Make sure that the beams cannot slide and that they
protrude from the frame equally. The chains must be held
parallel to the bodywork by chain spreaders in order not to
damage the dryer. The lifting equipment must be placed in
such a way that the dryer will be lifted perpendicularly. Lift
smoothly and avoid twisting.
3.1 Initial start (Fig. 10)
1. At least 4 hours before starting, the mains supply to the
dryer must be switched on to energize the crankcase heater,
which warms up the oil. The indicator lamp (H1) is then
alight.
2. Open the refrigerant shut-off valves (11-Fig. 2 and on water-
cooled dryers also 4-Fig. 5a) as follows: take the protecting
cap off the valve, then screw the spindle fully out and refit
the cap.
3. Onair-cooled dryers, press run/stand-by button (S1). Check
thatthe sense of rotation of the fan motor is correct. Cooling
air must be drawn in through the condenser (3-Figs. 4) and
blown over the refrigerant compressor (M1-Fig. 4a) to
outsidethe dryer.If wrong, switch offthevoltage andreverse
two of the three phase connections at the mains terminals.
3.2 Starting (Fig. 10)
1. Switch on the voltage at least 4 hours before starting, to
H1. Indicator lamp, voltage on
H2. Indicator lamp, dryer on
H3. Alarm indicator lamp, high pressure
dewpoint temperature
P1. Pressure dewpoint temperature gauge
P2. Temperature gauge, air inlet 1)
P3. Temperature gauge, evaporating
temperature 1)
P4. Temperature gauge, condensing
temperature 1)
S1. Run/stand-by button
The numbered items are
pictographs for:
1. Temperature
2. Air inlet
3. Air outlet
4. Air/air heat exchanger
5. Air/refrigerant heat exchanger
6. Condensate trap
7. Pressure dewpoint temperature
8. Refrigerant expansion valve
9. Start/Stop button
10. Alarm
11. Voltage on
12. Refrigerant compressor
13. Condenser
14. Refrigerant liquid dryer
1) Optional equipment Fig. 10. Instrument panel

2920 1351 01
16
Instruction book
energize the crankcase heater. Never start the dryer without
preheating as this may cause serious damage to the
refrigerant compressor.
Check that voltage on indicator lamp (H1) is alight.
2. On water-cooled dryers, open the cooling water shut-off
valves.
3. Press run/stand-by button (S1). Check that dryer on
indicator lamp (H2) is alight.
4. If the air inlet valve is closed, open it a little to pressurize
the dryer gradually; open the valve when the dryer is
pressurized.
5. Approx. 5 minutes later, load the dryer by opening the air
outlet valve.
Close the by-pass valve if installed.
6. After approx. 10 minutes, the nominal pressure dewpoint
temperature will be reached.
3.3 During operation
At regular intervals check:
1. Pressure dewpoint temperature gauge (P1-Fig. 10).
2. That condensate trap (1-Fig. 4a and 6-Fig. 5a) is operative.
If the operation is doubtful, flush the trap as per point 3 1).
3. Regularly open manual drain valve (2-Fig. 8) for approx.
10 seconds to discharge condensate and possible impurities.
3.4 Stopping (Fig. 10)
1. Flush the condensate trap (see section 3.3).
2. Close the dryer air outlet valve. It is not necessary to close
its air inlet valve. Only if the air net requires so, open the
by-pass valve and close the air inlet valve.
3. Press button (S1) to the stand-by position. The dryer stops.
Voltage on lamp (H1) remains alight. The crankcase heater
remains switched on. Disconnect the dryer from the mains
if it is going to be out of service for a long period or when
maintenance is needed.
Leave the isolating switch closed if the dryer has to remain
stand-by.
4. On water-cooled dryers, close the cooling water shut-off
valves.
3.5 Possible causes of unstable or too high
pressure dewpoint temperature
1. Dryer overload
- Compressed air flow exceeds capacity of dryer
- Working pressure too low
- Air inlet temperature too high
- Ambient temperature too high
- On water-cooled dryers, insufficient cooling water flow
2. Refrigeration system problems or maladjustment
- Maladjustment of the refrigerant expansion valve (7-
Fig. 4b and 9-Fig. 5b)
- Shortage of refrigerant in circuit through leakage
- Condenser externally clogged (air-cooled dryers)
- Malfunctioning of fan control switch (S3-Fig. 4b) on
air-cooled dryers or malfunctioning of the cooling water
regulating valve (3-Figs. 5) on water-cooled dryers
Note: The pressure dewpoint temperature will deviate from
nominal when the nominal conditions are exceeded, e.g. a
pressure dewpoint temperature of +7°C can be considered as
normal if the air flow, the air inlet temperature or the ambient
temperature is higher than nominal.
4 MAINTENANCE
Maintenance and repair work other than routine attention,
especially on the refrigeration circuits, must only be carried
out by qualified personnel and with the proper equipment.
Safety precautions
When handling refrigerant R404a, all applicable safety
precautions must be observed. The following points are
specially stressed:
- Contact of refrigerant with the skin will cause freezing.
Special gloves must be worn and in case of contact, the
skin should be rinsed with water. On no account may
clothing be removed.
- Fluid refrigerant will also cause freezing of the eyes;
therefore, safety glasses are a must.
- Refrigerant R404a is not inflammable but it is poisonous.
Do not inhale refrigerant vapours. Check that the working
area is adequately ventilated.
Local law may impose that:
- work on the refrigerant circuit of the cooling dryer or on
any equipment which influences its function should be
executed by an authorized control body.
- the installation should be checked once a year by an
authorized control body.
General
1. Keep the dryer clean.
2. On air-cooled dryers, brush or blow off the finned surface
of condenser (3-Figs. 4) regularly.
3. Once every six months inspect and clean the inner
components of condensate trap (1-Fig. 4a and 6-Fig. 5a).
1) - Not necessary when an electronic interval drain has been
installed.
- At initial start-up the condensate trap must be flushed more
frequently.

2920 1351 01 17
Instruction book
5 SETTINGS
The regulating and safety devices are factory-adjusted to obtain
optimum performance of the dryer. Altering the setting of any
of the devices must be avoided.
5.1 Automatic expansion valve
The automatic expansion valve (7-Fig. 4b and 9-Fig. 5b) is a
regulator which keeps the evaporator pressure, and
consequently also the temperature, stable. The valve is factory-
set to keep the evaporator pressure at no-load at a minimum of
5.2 bar(e) (75 psig), which corresponds to 1°C (34°F).
5.2 Switches (Figs. 4b and 5b)
Fan control switch (S3) and high pressure shut-down switch
(S2) are factory-adjusted and must be replaced if they deviate.
Cut-out at: Switch-on at:
bar(e) psig bar(e) psig
Fan control switch
- 50 Hz . . . . . . . . . . . . . . . 17 247 18 261
- 60 Hz . . . . . . . . . . . . . . . 18 261 19 276
High pressure shut-down
switch . . . . . . . . . . . . . . . . 29 421 25.6 371
M1. Refrigerant compressor/motor
1. Liquid refrigerant receiver
2. Liquid refrigerant dryer/filter
3. Condensate trap
4. Refrigerant shut-off valve
5. Flow regulating valve
6. Liquid separator
7. Condenser
Fig. 11. Front view of FD380 W
1. Key, value up
2. Key, value down
3. Display
4. Key, differential value (dT)
5. Key, set point of maximum pressure dewpoint
Fig. 12. Detail of pressure dewpoint indicator
F6843
6
2
4
1
3
M1
5
7

2920 1351 01
18
Instruction book
6 PROBLEM SOLVING
Mechanical faults and their suggested remedies
Explanation about the table below:
- Conditions of the dryer, always preceded by a number, are
printed in bold.
- Each possible fault is followed by its related suggested
remedy and both are preceded by the same letter.
1. Pressure dewpoint temperature too high
a. Air inlet temperature too high
a. Check and correct; if necessary, install a pre-cooler
b. Ambient temperature too high
b. Check and correct; if necessary, draw the cooling air
via a duct from a cooler place or relocate the dryer
c. Insufficient cooling water flow
c. Check and increase water flow, check cooling water
regulating valve
d. Cooling water inlet temperature too high
d. Decrease cooling water inlet temperature, as necessary
e. Air inlet pressure too low
e. Increase the inlet pressure
f. Dryer capacity is exceeded
f. Reduce the air inlet volume flow
g. Shortage of refrigerant
g. Consult Atlas Copco
h. Refrigerant compressor does not run
h. See 3
i. Evaporator pressure is too high
i. See 7
j. Condenser pressure is too high
j. See 2
k. Automatic drain of condensate trap inoperative
k. Flush the assembly by opening the manual drain valve.
Have system inspected
2. Condenser pressure too high or too low
a. Fan control switch out of order
a. Test and replace the switch if necessary
b. Fan or fan motor out of order
b. Check and correct as necessary
c. Ambient temperature too high
c. See 1b
d. Condenser externally clogged
d. Clean the condenser
e. Insufficient cooling water flow
e. See 1c
f. Cooling water inlet temperature too high
f. See 1d
3. Compressor stops or does not start
a. Electric power supply to compressor is interrupted
a. Check and correct as necessary
b. The internal thermic protection of the motor has tripped
b. The compressor will restart when the motor windings
have cooled down. Check also for undervoltage
c. The high pressure shut-down switch has tripped
c. The compressor will restart when the pressure has
decreased
d. The thermal overload protection of the fan motor has
tripped, causing high pressure
d. The fan motor will restartwhen the windings have cooled
down
4. Pressure drop over dryer too high
a. Air inlet strainer clogged
a. Depressurize dryer and clean inlet strainer
5. Condensate trap remains inoperative
a. Automatic drain system clogged
a. Flush the assembly by opening the manual drain valve
6. Condensatetrap continuously discharges air and water
a. Automatic drain system out of order
a. Have system inspected
7. Evaporator pressure is too high or too low
a. Expansion valve incorrectly set
a. Have expansion valve setting adjusted
b. Expansion valve out of order
b. Have expansion valve replaced
c. Condenser pressure too high or too low
c. See 2
d. Shortage of refrigerant
d. Consult Atlas Copco

2920 1351 01 19
Instruction book
7 PRINCIPAL DATA
7.1 Limitations/nominal conditions
50 Hz 60 Hz
Nominal conditions
Compressed air inlet pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . bar(e) 7 7
Compressed air inlet temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . °C 35 38
Ambient temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . °C 25 38
Inlet relative vapour pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
Pressure dewpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . °C 3 4
Cooling air/water inlet temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . °C 25 38
Limitations
Maximum compressed air inlet pressure . . . . . . . . . . . . . . . . . . . . . . . bar(e) 14.5 14.5
Min.-max. ambient air/water inlet temperature . . . . . . . . . . . . . . . . . . °C 0-45 0-45
Min.-max. compressed air inlet temperature . . . . . . . . . . . . . . . . . . . . °C 0-55 0-55
Maximum cooling water inlet pressure . . . . . . . . . . . . . . . . . . . . . . . . bar(e) 10 10
7.2 Specific data
Air dryer FD 260/260 W 300/300 W 380/380 W
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indoors Indoors Indoors
Medium to be dried . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Air Air
Volume flow at dryer inlet at nominal conditions . . . . . 50 Hz . . . . . l/s 260 314 380
60 Hz . . . . . l/s 290 340 463
Pressure drop through dryer at nominal conditions, approx.
50 Hz . . . . . bar 0.09 0.15 0.09
60 Hz . . . . . bar 0.15 0.09 0.15
Total cooling medium flow:
- Air-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . l/s 1800 1800 1800
60 Hz . . . . . l/s 2000 2000 2000
- Water-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . l/s 0.50 0.50 0.50
60 Hz . . . . . l/s 0.60 0.60 0.60
Electric power input
- Air-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . kW 3.55 3.95 4.55
60 Hz . . . . . kW 4.9 5.6 6.1
- Water-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . kW 3.0 3.4 4.0
60 Hz . . . . . kW 4.1 4.8 5.3
Refrigerant
Difluormonochlormethane CHF2Cl. . . . . . . . . . . . . . . . . . . . . . . . . . . R404a R404a R404a
Total charge, approx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg 8 8 8

2920 1351 01
20
Instruction book
Air dryer FD 450/450 W 700/700 W
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indoors Indoors
Medium to be dried . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Air
Volume flow at dryer inlet at nominal conditions . . . . . . . . . . . . . . . . 50 Hz . . . . . l/s 450 775
60 Hz . . . . . l/s -- 705
Pressure drop through dryer at nominal conditions, approx.. . . . . . . . 50 Hz . . . . . bar 0.15 0.27
60 Hz . . . . . bar -- 0.21
Total cooling medium flow:
- Air-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . l/s 1800 2350
60 Hz . . . . . l/s -- 2600
- Water-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . l/s 0.50 0.60
60 Hz . . . . . l/s -- 0.80
Electric power input
- Air-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . kW 5.1 7.70
60 Hz . . . . . kW -- 11.8
- Water-cooled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Hz . . . . . kW 4.55 6.50
60 Hz . . . . . kW -- 10.20
Refrigerant
Difluormonochlormethane CHF2Cl. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R404a R404a
Total charge, approx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kg 8 16
8 Conversion list of SI units into British/US units
1 bar = 14.504 psi
1 g = 0.035 oz
1 kg = 2.205 lb
1 km/h = 0.621 mile/h
1 kW = 1.341 hp (UK and US)
1 l = 0.264 US gal
1 l = 0.220 Imp gal (UK)
1 l = 0.035 cu.ft
1 m = 3.281 ft
1 mm = 0.039 in
1 m3/min = 35.315 cfm
1 mbar = 0.401 in wc
1 N = 0.225 lbf
1 Nm = 0.738 lbf.ft
x °C = (32 + 1.8x) °F 1)
1) A temperature difference of 1°C = a temperature difference of 1.8°F