Atlas Copco

Heatless adsorption compressed air dryers

CD 1+, CD 2+, CD 3+, CD 5+, CD 7+, CD 10+, CD 12+, CD 1.5+, CD 17+,

CD 22+, CD 2.5+

Instruction book
Atlas Copco
Heatless adsorption compressed air dryers

CD 1+, CD 2+, CD 3+, CD 5+, CD 7+, CD 10+, CD 12+, CD

1.5+, CD 17+, CD 22+, CD 2.5+
From following serial No. onwards: API W50 000

Instruction book
Original instructions

Copyright notice
Any unauthorized use or copying of the contents or any part thereof is prohibited.
This applies in particular to trademarks, model denominations, part numbers and drawings.
This instruction book is valid for CE as well as non-CE labelled machines. It meets the
requirements for instructions specified by the applicable European directives as identified
in the Declaration of Conformity.

2010 - 10
No. 2920 7083 20

www.atlascopco.com
 Instruction book

Table of contents

1 Safety precautions..........................................................................................................4

1.1 SAFETY ICONS...................................................................................................................................4

1.2 SAFETY PRECAUTIONS, GENERAL...........................................................................................................4

1.3 SAFETY PRECAUTIONS DURING INSTALLATION...........................................................................................5

1.4 SAFETY PRECAUTIONS DURING OPERATION..............................................................................................6

1.5 SAFETY PRECAUTIONS DURING MAINTENANCE OR REPAIR...........................................................................7

2 General description........................................................................................................9

2.1 GENERAL DESCRIPTION.......................................................................................................................9

2.2 OPERATION.....................................................................................................................................11

3 Electrical diagram.........................................................................................................15

4 Installation.....................................................................................................................17

4.1 DIMENSION DRAWINGS.......................................................................................................................17

4.2 INSTALLATION PROPOSAL...................................................................................................................19

5 Electrical connections..................................................................................................23

6 Operating instructions.................................................................................................30

7 Maintenance..................................................................................................................32

7.1 MAINTENANCE.................................................................................................................................32

7.2 RESETTING THE SERVICE TIMER..........................................................................................................51

7.3 DISPOSAL OF USED MATERIAL.............................................................................................................51

8 Problem solving............................................................................................................52

9 Technical data...............................................................................................................54

9.1 REFERENCE CONDITIONS...................................................................................................................54

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9.2 LIMITATIONS FOR OPERATION..............................................................................................................54

9.3 TECHNICAL SPECIFICATIONS................................................................................................................54

10 Instructions for Use......................................................................................................58

11 Guidelines for inspection.............................................................................................59

12 Pressure Equipment Directives...................................................................................60

13 Declaration of conformity............................................................................................61

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1 Safety precautions

1.1 Safety icons

Explanation

Danger for life

Warning

Important note

1.2 Safety precautions, general

General precautions

All responsibility for any damage or injury resulting from neglecting these precautions, or
non-observance of the normal caution and care required for installation, operation,
maintenance and repair, even if not expressly stated, will be disclaimed by the
manufacturer.

1. The dryers are designed for normal indoor use.

2. The operator must employ safe working practices and observe all related work safety requirements and
regulations.
3. If any of the following statements does not comply with the applicable legislation, the stricter of the two
shall apply.
4. Installation, operation, maintenance and repair work must only be performed by authorized, trained,
specialized personnel.
5. The dryer is not considered capable of producing air of breathing quality. To obtain air of breathing quality,
the compressed air must be adequately purified according to the applicable legislation and standards.
6. Before any maintenance, repair work, adjustment or any other non-routine checks, stop the dryer, press
the emergency stop button, switch off the voltage and depressurize the dryer. In addition, the power
isolating switch must be opened and locked.
7. Never play with compressed air. Do not apply the air to your skin or direct an air stream at people. Never
use the air to clean dirt from your clothes. When using the air to clean equipment, do so with extreme
caution and wear eye protection.
8. The owner is responsible for maintaining the dryer in safe operating condition. Parts and accessories shall
be replaced if unsuitable for safe operation.
9. It is not allowed to walk or stand on the dryer or its components.

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1.3 Safety precautions during installation

Precautions during installation

1. The dryer must only be lifted using suitable equipment and in accordance with the applicable safety
regulations. Loose or pivoting parts must be securely fastened before lifting. It is strictly forbidden to
dwell or stay in the risk zone under a lifted load. Lifting acceleration and deceleration must be kept within
safe limits. Wear a safety helmet when working in the area of overhead or lifting equipment.
2. Place the dryer where the ambient air is as cool and clean as possible. If necessary, install a suction duct.
Never obstruct the air inlet. Care must be taken to minimize the entry of moisture at the inlet air.
3. Any blanking flanges, plugs, caps or desiccant bags must be removed before connecting the pipes.
4. Air hoses must be of correct size and suitable for the working pressure. Never use frayed, damaged or
worn hoses. Distribution pipes and connections must be of the correct size and suitable for the working
pressure.
5. The aspirated air must be free of flammable fumes, vapours and particles, e.g. paint solvents, that can lead
to internal fire or explosion.
6. Arrange the air intake so that loose clothing worn by people cannot be sucked in.
7. Ensure that all piping is free to expand under heat and that it is not in contact with or close to flammable
materials.
8. No external force may be exerted on the air outlet valve. The connected pipe must be free of strain.
9. If remote control is installed, the machine must bear a clear sign stating "Danger: This machine is remotely
controlled and may start without warning".
The operator has to make sure that the machine is stopped and that the isolating switch is open and locked
before any maintenance or repair. As a further safeguard, persons switching on remotely controlled
machines shall take adequate precautions to ensure that there is no one checking or working on the
machine. To this end, a suitable notice shall be affixed to the starting equipment.
10. Air-cooled machines must be installed in such a way that an adequate flow of cooling air is available and
that the exhausted cooling air does not recirculate to the inlet.
11. The electrical connections must correspond to the applicable codes. The machines must be earthed and
protected against short circuits by fuses in all phases. A lockable power isolating switch must be installed
near the equipment.
12. On machines with automatic start-stop system or if the automatic restart function after voltage failure is
activated, a sign stating "This machine may start without warning" must be affixed near the instrument
panel.
13. Never remove or tamper with the safety devices, guards or insulation fitted on the machine. Every pressure
vessel or auxiliary installed outside the machine to contain air above atmospheric pressure must be
protected by a pressure-relieving device or devices as required.
14. Piping or other parts with a temperature in excess of 80˚C (176˚F) and which may be accidentally touched
by personnel during normal operation must be guarded or insulated. Other high-temperature piping must
be clearly marked.
15. For water-cooled machines, the cooling water system installed outside the machine has to be protected by
a safety device with set pressure according to the maximum cooling water inlet pressure.
16. If no safety valve is present in the air net close to the desiccant dryer (e.g. safety valve of compressor),
full flow safety valves must be installed on the dryer vessels.
17. If the maximum pressure of the compressor is higher than the design pressure of the dryer, a full flow
safety valve must be installed between the compressor and the dryer in order to blow off the excessive
pressure in case the safety valve of the dryer should be out of order or blocked.

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Also consult following safety precautions: Safety precautions during operation and Safety
precautions during maintenance or repair.
These precautions apply to machinery processing or consuming air or inert gas. Processing
of any other gas requires additional safety precautions typical to the application which are not
included herein.
Some precautions are general and cover several machine types and equipment; hence some
statements may not apply to your machine.

1.4 Safety precautions during operation

Precautions during operation

1. Always be careful when touching any piping or components of the dryer during operation. On dryers using
heat to regenerate the desiccant, some parts will become very hot.
2. Use only the correct type and size of hose end fittings and connections. When blowing through a hose or
air line, ensure that the open end is held securely. A free end will whip and may cause injury. Make sure
that a hose is fully depressurized before disconnecting it.
3. Persons switching on remotely controlled machines shall take adequate precautions to ensure that there
is no one checking or working on the machine. To this end, a suitable notice shall be affixed to the remote
start equipment.
4. Never operate the machine when there is a possibility of taking in flammable or toxic fumes, vapours or
particles.
5. Never operate the machine below or in excess of its limit ratings.
6. Keep all bodywork closed during operation. Bodywork should be opened for short periods only, e.g. to
carry out routine checks. Wear ear protectors when removing a panel.
7. People staying in environments or rooms where the sound pressure level reaches or exceeds 90 dB(A)
shall wear ear protectors.
8. Periodically check that:
• All guards are in place and securely fastened
• All hoses and/or pipes inside the machine are in good condition, secure and not rubbing
• There are no leaks
• All fasteners are tight
• All electrical leads are secure and in good order
• Safety valves and other pressure-relief devices are not obstructed by dirt or paint
• Air outlet valve and air net, i.e. pipes, couplings, manifolds, valves, hoses, etc. are in good condition,
free of wear or abuse
9. If warm cooling air from dryers is used in air heating systems, e.g. to warm up a working area, take
precautions against air pollution and possible contamination of the breathing air.
10. Do not remove any of, or tamper with, the sound-damping material.
11. Never remove or tamper with the safety devices, guards or insulations fitted on the machine. Every pressure
vessel or auxiliary installed outside the machine to contain air above atmospheric pressure shall be
protected by a pressure-relieving device or devices as required.

Also consult following safety precautions: Safety precautions during installation and Safety
precautions during maintenance or repair.
These precautions apply to machinery processing or consuming air or inert gas. Processing
of any other gas requires additional safety precautions typical to the application which are not
included herein.
Some precautions are general and cover several machine types and equipment; hence some
statements may not apply to your machine.

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1.5 Safety precautions during maintenance or repair

Precautions during maintenance or repair

1. Always use the correct safety equipment (such as safety glasses, gloves, safety shoes, etc.).
2. Use only the correct tools for maintenance and repair work.
3. Use only genuine spare parts.
4. All maintenance work shall only be undertaken when the machine has cooled down.
5. A warning sign bearing a legend such as "Work in progress - do not start" shall be attached to the starting
equipment.
6. Persons switching on remotely controlled machines shall take adequate precautions to ensure that there
is no one checking or working on the machine. To this end, a suitable notice shall be affixed to the remote
starting equipment.
7. Close the dryer air outlet valve before connecting or disconnecting a pipe.
8. Before removing any pressurized component, effectively isolate the machine from all sources of pressure
and relieve the entire system of pressure.
9. Never use flammable solvents or carbon tetrachloride for cleaning parts. Take safety precautions against
toxic vapours of cleaning liquids.
10. Scrupulously observe cleanliness during maintenance and repair. Keep dirt away by covering the parts
and exposed openings with a clean cloth, paper or tape.
11. Never weld on, or in any way modify, pressure vessels.
12. Whenever there is an indication or any suspicion that an internal part of a machine is overheated, the
machine shall be stopped but no inspection covers shall be opened before sufficient cooling time has
elapsed; this to avoid the risk of spontaneous ignition of the oil vapor when air is admitted.
13. Never use a light source with open flame for inspecting the interior of a machine, pressure vessel, etc.
14. Make sure that no tools, loose parts or rags are left in or on the machine.
15. All regulating and safety devices shall be maintained with due care to ensure that they function properly.
They may not be put out of action.
16. Before clearing the machine for use after maintenance or overhaul, check that operating pressures,
temperatures and time settings are correct. Check that all control and shut-down devices are fitted and that
they function correctly.
17. Protect the motor, electrical and regulating components, etc. to prevent moisture from entering them, e.g.
when steam-cleaning.
18. Make sure that all sound-damping material and vibration dampers, e.g. damping material on the bodywork,
is in good condition. If damaged, replace it by genuine material from the manufacturer to prevent the
sound pressure level from increasing.
19. Never use caustic solvents which can damage materials of the air net, e.g. polycarbonate bowls.
20. The following safety precautions are stressed when handling refrigerant:
• Never inhale refrigerant vapours. Check that the working area is adequately ventilated; if required, use
breathing protection.
• Always wear special gloves. In case of refrigerant contact with the skin, rinse the skin with water. If
liquid refrigerant contacts the skin through clothing, never tear off or remove the latter; flush
abundantly with fresh water over the clothing until all refrigerant is flushed away; then seek medical
first aid.
21. The following safety precautions are stressed when handling desiccant:
• Take precautions not to inhale desiccant dust.
• Check that the working area is adequately ventilated; if required, use breathing protection.
• Do not overfill the dryer when replacing desiccant.

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Also consult following safety precautions: Safety precautions during installation and Safety
precautions during operation.
These precautions apply to machinery processing or consuming air or inert gas. Processing
of any other gas requires additional safety precautions typical to the application which are not
included herein.
Some precautions are general and cover several machine types and equipment; hence some
statements may not apply to your machine.

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2 General description

2.1 General description

Introduction
The air dryers described in this book are heatless adsorption dryers, built to remove moisture from compressed
air for industrial purposes.
The dryer is intended to reach a pressure dew point of -40 ˚C (-40 ˚F). A pressure dew point of -70 °C (-94
°F) can be achieved by decreasing the inlet flow rate (see inlet flow correction factors, section Technical
data).
All units are designed for indoor use, and altitude up to 2000 m.

CD 1+ up to CD 3+ , General view

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CD 5+ up to CD 22+ , General view

Main parts
An overview of the main parts of the dryer is given in below figures:

CD 1+ up to CD 22+, Front view

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CD 1+ up to CD 22+, Back view

Reference Description Reference Description

1 Tower A 5 Solenoid valve
2 Tower B 6 Silencers
3 Air inlet 7 Valve block
4 Air outlet 8 Controller

2.2 Operation

General
The construction of the air dryer is simple, reliable and easy to service. A dryer has basically two towers,
containing the adsorption material or desiccant. This desiccant is a very porous grain material, able to adsorb
large amounts of water vapour.

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Flow diagram

Reference Designation Reference Designation

1 Air inlet 7 Electrical control line
2 Controller 8 Flow restriction
3 Left desiccant tower 9 Check valve
4 Right desiccant tower 10 Selector valve
5 Air outlet 11 Pneumatic silencer
6 Flow line 12 Solenoid valve

Operation principle
The operation cycle of the dryer is repetitive and is controlled by a factory-set timer. While the desiccant in
one tower dries the compressed air, the desiccant in the second tower is being regenerated. Regeneration of
the desiccant is achieved by means of purge air from the drying tower.
The compressed air entering the dryer is led to one of the towers by means of the bottom selector valve. The
position of the selector valve depends on the condition (activated or not) of the solenoid valves. As the air
flows upwards through the tower, the desiccant adsorbs the water vapour and the compressed air is dried.
Once the top of the tower is reached, the air leaves the dryer via the check valve.
A small portion of the dried air passes a nozzle, expands to atmospheric pressure and flows downwards through
the other tower, regenerating (drying) the desiccant. A nozzle for operation of the dryer at 7 bar is installed

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as standard. Alternative nozzles for use at other operating pressures are available as sales kit. Please consult
the spare parts list for specific information. The regeneration air is released via the corresponding solenoid
valve and the silencer. The solenoid valves are controlled by the timer.
After a pre-set period, the function of the towers is reversed. The fully regenerated tower will now dry the
air, while the desiccant in the other tower will be regenerated.
By default, the regeneration timer will restart from the beginning of the cycle in case of a power failure during
operation.
However, in case the input of remote control connector X3 (see section Electric diagram) is opened (by the
freeze contact), the dryer will "freeze" the drying cycle: purge air flow stops, both solenoid valves are closed.
When the contact, connected to connector X3 closes, the dryer will continue normal operation. This feature
can prevent loss of compressed air (purge air) when the compressor is not continuously running loaded. On
compressors with load/unload regulation, X3 can be connected to a voltage free contact of the compressor
(contact open when the compressor runs unloaded). If no free contact is available, an additional voltage free
contact should be installed on the load/unload contactor of the compressor to use this feature. See section
Electrical connections for more details.

Do not connect X3 when an air receiver is installed before the dryer.

X3 should only be connected when the air receiver is installed downstream of the dryer.

Control panel

Control panel with flow diagram

Reference Designation Reference Designation

1 LED <Power On> 7 Air outlet
2 LED <Right tower drying> 8 Inlet selector valve
3 LED <Left tower drying> 9 Outlet selector valve
4 LED <Service warning> 10 Solenoid valves
5 LED <Service alarm> 11 Service reset

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Reference Designation Reference Designation

6 Air inlet

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3 Electrical diagram

Controller connections

X3 (Freeze contact): to freeze the regeneration cycle when the compressor runs unloaded, remove the jumper
wire and connect pin 1 and 2 of connector X3 with the potential free contact of the compressor (contact open
= freeze). See also section Electrical connections.

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Alarm contact: When the controller is switched on, the contacts remain closed unless an alarm contact is
required. The contacts open if the mains power fails, or the internal power supply fails.

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4 Installation

4.1 Dimension drawings

Dimensions CD 1+ up to CD 3+

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Dimensions CD 5+ up to CD 22+

Reference Designation
1 Inlet
2 Outlet
3 Removable panels
4 Electrical connection options
5 Filter mounting holes

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4.2 Installation proposal

Piping

Make sure that all pipes, filters, valves, etc. are clean and that they are installed correctly with
or without bypass system.
Make sure that the piping is installed stress-free. For more information concerning air nets,
cooling systems etc., refer to the compressor installation manual.

To ensure correct operation of the dryer, it has to be fitted properly into the compressed air circuit. Depending
from the fact if the remote control connector X3 is used or not (see section Operation), there are two
possibilities:

X3 is not used

If the X3 connection is not used, the correct installation sequence is compressor - air
receiver - dryer.

Installation without use of the X3 connection with the compressor

Reference Designation Reference Designation

1 Compressor 4 PD filter
2 Water separator 5 Dryer
3 DD filter (not required) 6 Receiver

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X3 is used

If the X3 connection is used, the correct installation sequence is compressor - dryer - air
receiver.

Installation in case the X3 connection with the compressor is used

Reference Designation Reference Designation

1 Compressor 4 PD filter
2 Water separator 5 Dryer
3 DD filter (not required) 6 Receiver

General recommendations
Important: Keep the following in mind when installing the dryer:
• Place the dryer at a location where the temperature never exceeds the limits, see section Limitations for
operation.
• The dryer does not require extra ventilation.
• Fix the dryer as level as possible to the wall or to the floor. For certain models, a wall mounting kit is
available as option - see spare parts book for part numbers. Make sure the fixating screws are tightened
firmly and that the wall or the floor is suitable for taking the weight of the dryer.
• Provide enough space around the dryer to install and service the filter elements. A minimum free space
of 800 to 1000 mm is recommended.
If the filters are mounted directly onto the dryer, the dryer should eventually be positioned higher to enable
servicing of the filter elements.

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• Use a PD filter at the inlet of the dryer. A filter at the outlet is not needed, since the desiccant cartridge
has an integrated dust filter. Should oil vapour and odours be undesirable, a QD carbon filter can be
installed downstream the DDp filter.
• If the compressor has no built-in water separator or if the dryer is not located near the compressor, a water
separator (WSD) has to be installed before the dryer in order to prevent free water from entering the dryer,
as free water can damage the desiccant. If the condensate contains oil, install an oil/water separator for
draining of pure condensate water (consult your supplier).
• The drain hoses of the water separator and the filters must not dip into the sewer.
• It is recommended to install bypass pipes with ball valves over the filters in order to isolate the filters
during service operations without disturbing the compressed air delivery.
• It is required to install pressure relief valves on the dryer when ball valves are installed at the inlet and the
outlet of the dryer to isolate the dryer from the air net.
• If dryers are used in parallel make sure that all dryers can be bypassed through one of the other dryers,
as shown in below figure:

Parallel installation

Reference Designation Reference Designation

1 Compressor 5 Dryer
2 Water separator 6 Receiver
3 DD filter (not required) 7 Inlet valve
4 PD filter 8 Outlet valve

Never overload the dryer as this will damage the desiccant. It may be recommended to install
the air dryer upstream of the air receiver to prevent overload (e.g. after extending the dry air
circuit). Consult Atlas Copco if in doubt.

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Horizontal installation

Description Figure
Inlet filter as fitted to the dryer in vertical orientation.
A mounting kit allows to couple the filter directly to the inlet
manifold (CD 1+ up to CD 3+). For CD 5+ up to CD 22+, an
adaptor nipple is supplied as standard.

For horizontal installation, the dryer must be suitably

supported. It has to be oriented as shown only (not on one
of its sides).
A nipple adaptor is required for connection of the pre-filter.

The inlet filter must be fitted vertically and coupled as

closely to the inlet port on the manifold.
a) The filter can also be mounted directly onto the bottom
manifold. In this setup, the inlet on the top manifold should
be plugged.

Dryer in horizontal plane.

Consideration must be given to supporting and to
clearance for removal of the filter bowl.

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5 Electrical connections

General

The electrical wiring must comply with the local regulations. The air dryer must be earthed
and protected by fuses against short-circuiting. Consult the electric diagram delivered with
the dryer.
Before switching on the main power supply, check the voltage requirements in the technical
specifications or on the dryer’s data plate.

Refer to section Electric diagram.

Controller description
The controller is used to power two mains voltage solenoid valves, which are used as pilot valves to the main
exhaust diaphragm valves. In standard configuration, each solenoid valve is alternately energised for 120
seconds out of a half cycle time of 170 seconds. When the valve is not energised, the main exhaust diaphragm
valve is closed, meaning that the tower to which it is linked is pressurised. The two green LED's on the display
reflect the operation of the towers: the green LED is illuminated when the corresponding tower is pressurised.

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Timing cycle

Controller specifications
• Ambient temperature: 1.5 °C to 50 °C (35 °F to 122 °F)
• Maximum relative humidity (RH): 80% for temperatures up to 31 °C, decreasing linearly to 50% at 50
°C
• Input voltage: 110 or 230 VAC, 50-60 Hz
• Protection class: IP65, BS EN 60529
• Mains supply voltage fluctuations not to exceed +/- 10% of nominal
• Transient over voltage IEC 60664 Class II
• Pollution degree 2, IEC 60664
• Overall controller with gaskets fitted to valve connections
• Contact rating reed relay (alarm contact) : max. 300 V, 0.5 A, 10 W

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Controller connections

Controller connections

Mains connection
The mains cable is included with the product. The mains plug needs to be installed during commissioning.
Equipment intended for use in the EU does not have a fuse fitted to the mains plug and therefore requires a
separate fuse in the mains line. When used in the UK, a 3 A fuse should be fitted to the mains plug as per the
following wiring diagram.

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A circuit breaker or switch must be installed near the air dryer, shall be easy to reach, and shall be certified
according to EN60947-1 and EN60947-3. The switch or circuit breaker shall be marked as the disconnection
device for the air dryer and needs to be marked with On and Off positions.
DIN connector wiring

Output connections do not provide isolation from the mains. Connectors and interconnecting
wiring must meet EN61010-1:2001 requirements for reinforced insulation.

Energy management with Freeze contact (X3)

To freeze the regeneration cycle when the compressor runs unloaded, remove the jumper wire between pins
1 and 2 from the connector X3, and connect pin 1 and 2 of connector X3 with the potential free contact of the
compressor (contact open = freeze).
If the contact is opened, both solenoid valves will de-energise, closing the exhaust (no purge air consumption),
and both towers are pressurized.
Once the contact closes again (compressor runs loaded), the dryer will resume the cycle where it had left off.

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Picture of jumper wire

Reference Designation
1 Pin 1
2 Pin 2
3 Jumper wire

Alarm contact
When the controller is switched on, the contacts close and remain closed unless an alarm condition is required,
as follows:
• The contacts open if the main power fails, or the internal power supply fails. There is no LED indication
on the control unit. The contacts close if power is reconnected.
• The contacts open if either solenoid does not draw current when power is applied to it. The corresponding
green LED turns red and remains on until reset by the reed relay (underneath the blue bar icon).
• The contacts open when either the 11500 or 12000 hour service indicator LED's come on, and remain
open until reset. A service interval timer is included. An orange LED will flash after 11500 hours operation,
and a red LED will flash after 12000 hours. Consult section Resetting the service counter. The service
interval timer is reset by activation of a reed relay by means of an externally applied magnet. When the
reset switch is closed, the yellow and red LED's illuminate continuously.
The mains cable should be fed through the side cover panel of the dryer. In order to do so: cut out the middle
part of the grommet and lead the cable through.

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Mains cable

Controller display

LED no. Function Indication Remark

1 Power off No LED's illuminated. Power supply disconnected.
No alarm contact switched.
Power on Red LED continuous
3 Left tower pressurised Green LED continuous Left tower drying
2 Right tower pressurised Green LED continuous Right tower drying

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LED no. Function Indication Remark

2 and 3 Both towers pressurised Green LED continuous One tower drying, the other
tower repressurising
3 Left solenoid failure Left tower LED turns red
instead of green
2 Right solenoid failure Right tower LED turns red
instead of green
4 Service warning Orange flashing LED After 11500 hours continuous
(indicated on the yellow operation
spanner label)
5 Service alarm Red flashing LED (indicated on After 12000 hours continuous
the red spanner label) operation
4 and 5 Controller reset Orange warning LED and red Activated when the reset
alarm LED illuminate magnet is applied
continuously
Power failure No LED's illuminated.
Alarm contact switched

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6 Operating instructions

Safety

Always observe all relevant safety instructions.

Initial start-up
To start up the dryer for the first time or after a long period of standstill, proceed as follows:
1. If installed, open the bypass valves of the dryer.
2. Close off the air supply from the compressor towards the dryer by closing the external inlet valve (if
installed).
3. If installed, close the outlet valve.
4. Remove the silencers to prevent the silencers from getting clogged by the desiccant and wear a dust mask,
safety glasses and ear protection. (This is only required at initial start-up or after the desiccant was
replaced).
5. Start the compressor and wait for pressure.
6. Slowly open the inlet valve.
7. Check the connections of the dryer for air leaks and remedy if necessary.
8. Switch the dryer on by plugging in the power cord.
9. Let the dryer operate for several hours with the external outlet valve closed.
10. In case the silencers were removed, refit the silencers.
11. Gradually open the external outlet valve.
12. If applicable, close the bypass valves of the dryer.

If the application allows air that is not completely dry, the valve towards the dry air
consumer may be opened even before the optimal Pressure Dew Point (PDP) is reached.
In this case however, it will take more time for the desiccant to dry completely.
At initial start-up, and specially when the dryer is loaded from the beginning, it can take a
long time before the dew point is reached. For a dew point of -70 ˚C (-94 ˚F), it can take
up to more than 10 days before this value is reached.
It is therefore recommended to operate the dryer for a number of days with the outlet valve
closed.

Normal start
If the dryer has not been used for more than 3 months, refer to section Initial start-up. In all other cases, proceed
as follows:
1. Cut off the air supply from the compressor towards the dryer by closing the external inlet valve.
2. If installed, close the external outlet valve between the dryer and the dry air consumer.
3. Start the compressor and slowly open the external inlet valve.
4. Switch the dryer on by plugging in the power cord.
5. Gradually open the air outlet valve.
6. If applicable, close the bypass valves of the dryer.

Close the external inlet valve in case the compressor needs to be restarted. The high air
speed in the start-up phase of the compressor may damage the desiccant.

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During operation
At regular intervals, check the status of the LED's on the control panel. If the Warning/Alarm LED is alight,
consult the section Problem solving.

Stopping
To stop the dryer, proceed as follows:
1. If installed and if necessary, open the bypass valves of the dryer so that the application will still receive
compressed air.
2. Close the external inlet valve between the compressor and the dryer and the external outlet valve between
the dryer and the dry air consumer.
3. Let the dryer operate for a period without consumption, to depressurize the vessels.
4. Switch off the dryer by unplugging the power cord.

If the dryer is stopped for a longer period, keep the external inlet and outlet valve closed
to avoid moisture from entering the dryer.
Under no circumstances must compressed air be allowed to flow through the dryer when
the electrical power is switched off. This will result in terminal failure of the desiccant
material, causing regeneration will no longer be possible.

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7 Maintenance

7.1 Maintenance

General recommendations and precautions

The dryer does not need any specific maintenance. Nevertheless, before carrying out any maintenance or
corrective activity, read the following recommendations and safety precautions and act accordingly:
• Pull out the power cord or put the on/off switch S1 in position (whichever is applicable).
• Disconnect all pressure sources and vent the internal pressure of the system before dismantling any
pressurized component.
• Use genuine Atlas Copco spare parts only. Consult the Spare Parts List for part numbers. For preventive
maintenance, dedicated Service kits are available.
• Check for correct operation after maintenance.

Filters and valves installed between the compressor, the dryer and the air consumer
may need other maintenance activities than those mentioned below (e.g. draining the
filters and replacing the filter elements). Refer to the appropriate manual for more
information.

Preventive maintenance schedule

Frequency Service Plan Activity

Daily Check the display panel. Service information
can be found here.
Every 6 months • Check for damaged wiring or loose
connections.
• Check for air leaks.
Every year or every 6000 hours of operation A • Replace the inlet filter cartridge.
(1) • Replace the silencers.
Every 2 years or every 12000 hours of B • Service plan A.
operation (1) • Replace desiccant cartridges.
Every 4 years or every 24000 hours of C • Service plan B.
operation (1) • Replace exhaust valve diaphragm and
solenoid valves.
• Replace shuttle valve and o-rings.

(1) whichever comes first

It is recommended to have the desiccant replaced by a qualified Atlas Copco service technician.
At each 12000 hours service interval, the timer card needs to be reset with a magnetic key, see section Resetting
the service counter or the instruction, delivered with the service kits.
All spare parts required for scheduled maintenance are included in specific service kits. Consult the spare
parts list for part number information.

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Desiccant replacement procedure

CD 1+ up to CD 3+

Step Description Figure

1 Completely depressurise the dryer. Consult Stopping the dryer
in section Operating instructions.

2 Remove the four M8 bolts from the top manifold of the dryer.

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Step Description Figure

3 Remove the dryer from the air net (the top manifold is still
connected to the piping.

4 Remove the cartridges.

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Step Description Figure

5 Turn the valve locking caps a quarter turn and lift to release
them.
Take out purge plugs.

6 Remove the label from the top of the new cartridges.

Insert the old purge nozzles into the new cartridges, making
sure the O-rings are in place at the bottom of the plugs.
Put the locking caps back in place and turn a quarter to tighten.

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Step Description Figure

7 Insert the cartridges into the dryer.

8 Connect the dryer to the top manifold making sure the O-rings
are in place.

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Step Description Figure

9 Tighten the M8 bolts, making sure there are no leaks.
Follow the start-up procedure described in section Operating
instructions.

CD 5+ up to CD 22+

Step Description Figure

1 Completely depressurise the dryer. Consult Stopping the dryer
in section Operating instructions.

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Step Description Figure

2 Remove the four M10 bolts from the top cover of one tower of
the dryer.

3 Remove the top cover plate and O-ring from the dryer.

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Step Description Figure

4 Remove the cartridge from the dryer.

5 Take off the handle from the old cartridge by unscrewing the
M4 bolts and take out the spring and nozzle.

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Step Description Figure

6 Remove the label on top of the new cartridge.
Insert the nozzle in the new cartridge.
Place the spring on the top, and screw the handle back in place.

7 Insert the new cartridge into the dryer.

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Step Description Figure

8 Put the top cover back on, making sure the O-ring is in place.

9 Finally tighten the M10 bolts, making sure there are no leaks.

10 Repeat steps 2 to 9 for the other tower of the dryer.

11 Follow the start-up procedure described in section Operating
instructions.

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Purge nozzle replacement procedure

CD 1+ up to CD 3+

Step Description Figure

1 Completely depressurise the dryer. Consult Stopping the dryer
in section Operating instructions.

2 Remove the four M8 bolts from the top manifold of the dryer.

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Step Description Figure

3 Remove the dryer from the air net (leave top manifold
connected to the piping).

4 Turn the valve locking caps a quarter turn and lift to release
them.

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Step Description Figure

5 Remove the purge nozzles.

6 Insert the new purge nozzles, making sure the O-rings are in
place at the bottom of the plugs.

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Step Description Figure

7 Put the locking caps back in place and turn a quarter turn to
tighten.

8 Connect the dryer to the top manifold making sure the O-rings
are in place.

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Step Description Figure

9 Tighten the M8 bolts, making sure there are no leaks.
Follow the start-up procedure described in section Operating
instructions.

CD 5+ up to CD 22+

Step Description Figure

1 Completely depressurise the dryer. Consult Stopping the dryer
in section Operating instructions.

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Step Description Figure

2 Remove the four M10 bolts from the top cover of one tower of
the dryer.

3 Remove the top cover plate from the dryer.

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Step Description Figure

4 Remove two M4 bolts and take out the handle.

5 Remove the purge nozzle and spring.

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Step Description Figure

6 Insert the new purge nozzle with the spring on top.

7 Put the handle back on top of the purge nozzle and tighten the
two bolts.

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Step Description Figure

8 Put the top plate back on, making sure the O-ring is in place.

9 Finally tighten the M10 bolts making sure there are no leaks.

10 Repeat steps 2 to 9 for the other tower of the dryer.

11 Follow the start-up procedure described in section Operating
instructions.

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7.2 Resetting the service timer

Timer card resetting procedure

To reset the timer card, continue as follows:

• At 11500 hours, the orange service warning LED (4) will flash, indicating that service will be needed
soon.
• At 12000 hours, the red service alarm LED (5) will flash, indicating that service is required.
• Close off the dryer as described in the stopping procedure, see section Operating instructions.
• Pull out the power cord of the dryer. LED (1) (power on) will extinguish. Perform the service plan as
scheduled.
• Restart the dryer by reconnecting the power cord. Refer to the start-up procedure. The counter will restart,
the dryer operating LED (1) becomes alight, and LED's (2 and 3) indicate the cycling status of the dryer.
The service warning LED (4) or service alarm LED (5) are still flashing.
• Reset the timer card by putting the service magnet during 5 seconds over the reed relay, located behind
the blue bar icon indicated by area (11) of the control panel. When the reset switch is closed, the orange
and red LED's illuminate continuously. Next, take the magnet away from the blue bar icon. The service
warning and alarm LED (4 and 5) will go out.
The timer card has now been reset and normal operation continues. The service counter has been reset to 0 .

7.3 Disposal of used material

Used filters or any other used material (e.g. desiccant, lubricants, cleaning rags, machine parts, etc.) must be
disposed of in an environmentally friendly and safe manner, and in line with the local recommendations and
environmental legislation.

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8 Problem solving

Overview

Symptom Possible cause Corrective action

Poor dew point The dryer has not had the time to Close the valve installed between the dryer and
regenerate completely. the application (if permitted) and have the
desiccant regenerated.
Liquid water at dryer inlet Check pre-filtration and drains. Fit an extra
water separator if required.
Oil entering the dryer. Check pre-filtration. Oil damages the
desiccant. Replace the desiccant cartridges if
the desiccant has been contaminated.
Excessive flow Check actual flow against maximum specified.
Low inlet pressure Check pressure against specification, and use
inlet flow correction factors where required.
High inlet temperature Check temperature against specification, and
use inlet flow correction factors where required.
Silencer blocked or damaged Replace silencer.
Air leaks Tighten joints or fit new seals.
Dirty purge plug Clean purge plug.
Wrong size purge plug Refer to section Technical data for purge plug
selection.
Shuttle remains in one position Check if the exhaust valves closes off: No air
must leave from the silencer of the tower that is
drying. If air escapes from the silencer, check
the connections for air leaks. If no solution:
check the membranes.
The dryer produces a Check the silencer and its fixation to Replace the silencer or correct its fixation.
lot of noise. the unit.
Insufficient air leaves Too much purge air escapes. Check the condition of the solenoid valve and
the dryer. replace if necessary.
Check the fitting of the solenoid valve and tube
to the bonnet for air leaks.
Check if the correct purge nozzle is installed.
Excessive purge air Shuttle remains in one position Check if the exhaust valves closes off: No air
flow must leave from the silencer of the tower that is
drying. If air escapes from the silencer, check
the connections for air leaks.
Membrane sheared Check the membrane of the tower that is having
the high purge air flow.
Shuttle O-ring damaged If the shuttle does not seal, there will be a leak
path between inlet air and exhaust. Open the
valve block and inspect the shuttle O-ring.
Replace O-ring if needed.
Inlet pressure drops Shuttle O-ring damaged If the shuttle does not seal, there will be a leak
every cycle path between inlet air and exhaust. Open the
valve block and inspect the shuttle O-ring.
Replace O-ring if needed.

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Symptom Possible cause Corrective action

Low outlet pressure Blocked filter Check/replace filter elements.
Blocked filter desiccant cartridge Check/replace desiccant cartridge.
Excessive purge air flow See excessive purge air flow.
Dryer won't Incorrect start-up Keep downstream isolation valve closed. Open
pressurize upstream valve slowly. Power the dryer once
pressurised.
Package won't Faulty wiring to controller Check electrical wiring.
electrically energise Wrong supply Check the voltage supply.
Power LED does not illuminate Replace controller.

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9 Technical data

9.1 Reference conditions

Condition Unit Value
Compressed air effective inlet pressure bar 7
psi 101.5
Compressed air inlet temperature ˚C 35
˚F 95
Relative humidity of the air at inlet % 100
Pressure dew point (standard version) ˚C -40
˚F -40

9.2 Limitations for operation

Limitation Unit Value
Maximum compressed air effective inlet pressure bar 16
psi 232
Minimum compressed air effective inlet pressure bar 4
psi 58
Maximum ambient air temperature ˚C 50
˚F 122
Minimum ambient air temperature ˚C 1.5
˚F 35
Maximum compressed air inlet temperature ˚C 60
˚F 140
Minimum compressed air inlet temperature ˚C 1.5
˚F 35

9.3 Technical specifications

Specific data for CD 1+ up to CD 22+ (standard version, PDP -40 ˚C)

Desiccant type: molecular sieves

Specification Unit CD 1+ CD 1.5+ CD 2+ CD 2.5+ CD 3+

Max. volume flow at dryer inlet l/s 1 1.5 2 2.5 3
cfm 2.1 3.2 4.2 5.3 6.4
Regeneration air consumption % 18 18 18 18 18
average at max. flow

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Specification Unit CD 1+ CD 1.5+ CD 2+ CD 2.5+ CD 3+

Filter size PD 3 3 3 3 3
Mass kg 7 8 9 10 11
lb 15.5 17.6 19.8 22 24.2
Installed power (max) VA 8 8 8 8 8
Time of half a cycle s 170 170 170 170 170
Regeneration time s 120 120 120 120 120

Specification Unit CD 5+ CD 7+ CD 10+ CD 12+ CD 17+ CD 22+

Max. volume flow at l/s 5 7 10 12 17 22
dryer inlet cfm 10.6 14.8 21.2 25.4 36 46.6
Regeneration air % 18 18 18 18 18 18
consumption average
at max. flow
Filter size PD 9 9 9 17 17 17
Mass kg 19 22 25 29 35 44
lb 41.9 48.5 55.1 63.9 77.1 97
Installed power (max) VA 8 8 8 8 8 8
Time of half a cycle s 170 170 170 170 170 170
Regeneration time s 120 120 120 120 120 120

Specific data for CD 1+ up to CD 22+ (special version, PDP -70 °C)

Desiccant type: molecular sieves

Specification Unit CD 1+ CD 1.5+ CD 2+ CD 2.5+ CD 3+

Max. volume flow at dryer l/s 0.7 1.05 1.4 1.75 2.1
inlet cfm 1.5 2.2 3 3.7 4.4
Regeneration air % 25 25 25 25 25
consumption average at
max. flow
Filter size PD 3 3 3 3 3
Mass kg 7 8 9 10 11
lb 15.5 17.6 19.8 22 24.2
Installed power (max) VA 8 8 8 8 8
Time of half a cycle s 170 170 170 170 170
Regeneration time s 120 120 120 120 120

Specification Unit CD 5+ CD 7+ CD 10+ CD 12+ CD 17+ CD 22+

Max. volume flow l/s 3.5 4.9 7 8.4 11.9 15.4
at dryer inlet cfm 7.4 10.3 14.8 17.8 25.1 32.6

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Specification Unit CD 5+ CD 7+ CD 10+ CD 12+ CD 17+ CD 22+

Regeneration air % 25 25 25 25 25 25
consumption
average at max.
flow
Filter size PD 9 9 9 17 17 17
Mass kg 19 22 25 29 35 44
lb 41.9 48.5 55.1 63.9 77.1 97
Installed power VA 8 8 8 8 8 8
(max)
Time of half a s 170 170 170 170 170 170
cycle
Regeneration s 120 120 120 120 120 120
time

Correction factors
Flow correction factors due to air inlet pressure

Operating 4 5 6 7 8 9 10 11 12 13 14 15 16
pressure
(bar)
Operating 58 72 87 100 116 130 145 160 174 189 203 218 232
pressure
(psi)
Pressure 0.62 0.75 0.87 1.00 1.12 1.25 1.37 1.50 1.62 1.75 1.87 2.00 2.12
correction
factor

Flow correction factors due to air inlet temperature

Temperature 20 25 30 35 40 45 50
(° C)
Temperature 68 77 86 95 104 113 122
(° F)
Temperature 1.07 1.06 1.04 1 0.88 0.67 0.55
correction factor

Flow correction factors due to pressure dew point

Dew point (° C) -40 -70

Dew point (° F) -40 -94
Dew point correction factor 1 0.7

Purge nozzle sets

The standard purge plug fitted in the dryer is intended for an operating pressure of 7 bar. Operation at a
different pressure may require a different purge nozzle to be fitted. Please refer to the table for details.

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Operating pressure Part number purge

nozzle kit
4 5.5 7 8.5 10 11.5 13 14.5 16
bar bar bar bar bar bar bar bar bar
CD 1+ 0.6 0.6 0.5 0.5 0.4 0.4 0.3 0.3 0.3 8092 3458 03
CD 1.5+ 0.8 0.7 0.6 0.6 0.5 0.5 0.5 0.4 0.4 8092 3458 11
CD 2+ 0.9 0.8 0.7 0.7 0.6 0.6 0.5 0.5 0.5 8092 3458 29
CD 2.5+ 1 0.9 0.8 0.7 0.7 0.7 0.6 0.6 0.6 8092 3458 37
CD 3+ 1.1 1.1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 8092 3458 45
CD 5+ 1.3 1.2 1 1 0.9 0.8 0.8 0.8 0.7 8092 3458 52
CD 7+ 1.6 1.4 1.2 1.2 1.1 1 1 0.9 0.9 8092 3458 60
CD 10+ 1.9 1.7 1.5 1.4 1.3 1.2 1.1 1.1 1 8092 3458 78
CD 12+ 2.1 1.9 1.6 1.5 1.4 1.3 1.2 1.2 1.1 8092 3458 86
CD 17+ 2.4 2.2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 8092 3458 94
CD 22+ 2.8 2.5 2.2 2.1 1.9 1.8 1.7 1.6 1.5 8292 3459 02

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10 Instructions for Use

Instructions

Step Description
1 The dryers can contain pressurized air. This can be potentially dangerous if the equipment
is misused.
2 The towers of the dryer consist of an extruded profile, which must only be used as a
compressed air vessel and must be operated within the limits specified. See section
Pressure Equipment Directives, table A.
3 No alterations must be made to the vessels by welding, drilling or other mechanical
methods without the written permission of the manufacturer.
4 The design pressure and temperature of this pressure bearing part must be clearly
indicated on the data label.
5 If installed, the safety valve must correspond with pressure surges of 1.1 times the
maximum allowable operating pressure. This should guarantee that the pressure will not
permanently exceed the maximum allowable operating pressure of the vessel.
6 Original bolts have to be used after opening for inspection. The maximum torque has to
be taken into consideration (see table below).

Maximum bolt torque

Thread size Tightening torque Allowed deviation

(Nm) (Nm)
M3 1 0.3
M4 2.4 0.6
M5 5 1.2
M6 8 2.1
M8 20 5
M10 41 10
M12 73 18
M14 115 29
M16 185 46
M18 238 60
M20 335 84

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11 Guidelines for inspection

Guidelines
On the Declaration of Conformity / Declaration by the Manufacturer, the harmonized and/or other standards
that have been used for the design are shown and/or referred to.
The Declaration of Conformity / Declaration by the Manufacturer is part of the documentation that is supplied
with this air dryer.
Local legal requirements and/or use outside the limits and/or conditions as specified by Atlas Copco may
require other inspection periods as mentioned below.

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12 Pressure Equipment Directives

Components Subject to 97/23/EC Pressure Equipment Directive

The category according to 97/23/EC of the pressure assembly, as well as the volume, is indicated in Table A
(see below).
Parts of article 3.3 of 97/23/EC are subject to Sound Engineering Practice (SEP).
Parts of category I according to 97/23/EC are integrated into the machine and fall under the exclusion of article
I, section 3.6.
Parts subject to the Simple Pressure Vessel Directive 87/404/EEC are excluded from 97/23/EC according to
article I, section 3.3.
The following table contains the necessary information for the inspection of all pressure equipment according
to the Pressure Equipment Directive 97/23/EC.
Design criteria for pressure equipment:
Table A

Dryer Tower Design Design PED Number Tower Tower Internal

type drawing p.n. pressure temperature category of cycles wall diameter volume
(bar(e)) (°C) thickness (mm) (l)
(mm)
CD 1+ 1624 7288 01 16 0 to +60 SEP 927 500 3 54 0.73
CD 1.5+ 1624 7288 02 0.85
CD 2+ 1624 7288 03 1.15
CD 2.5+ 1624 7288 04 1.40
CD 3+ 1624 7288 05 1.45
CD 5+ 1624 7235 01 16 0 to +60 I 927 500 4.5 105 3.03
CD 7+ 1624 7235 02 4.07
CD 10+ 1624 7235 03 5.07
CD 12+ 1624 7235 04 6.28
CD 17+ 1624 7235 05 II 8.49
CD 22+ 1624 7235 06 10.52

Recommendation of the manufacturer for the re-inspection time

Following actions are to be executed by authorised service personnel, unless stated differently in the applicable
legislation. The stated time interval has as reference the day of start-up of the unit.
• Every 6 months: visual check of tube (tower) material on the outside (exposed) for traces of strong
corrosion. Consult the service department of your supplier if necessary.
• Every 2 years or 12000 hours: when replacing the desiccant, following inspections are to be carried out:
• Inspection of outside and inside of the material for excessive and local corrosion,
• Inspection of outside and inside of the material for fissures, leaks, damage.
Consult the service department of your supplier if necessary.
• Every 10 years: hydrostatic test according to the Pressure Equipment Directive 97/23/EC. Consult the
service department of your supplier if necessary.

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13 Declaration of conformity

Typical example of a Declaration of Conformity document

(1): Contact address:

Atlas Copco Airpower n.v.
P.O. Box 100
B-2610 Wilrijk (Antwerp)
Belgium

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In order to be First in Mind—First in Choice® for all your quality
compressed air needs, Atlas Copco delivers the products and
services that help to increase your business’ efficiency and
profitability.
Atlas Copco's pursuit of innovation never ceases, driven by our
need for reliability and efficiency. Always working with you, we are
committed to providing you the customized quality air solution that
is the driving force behind your business.

No. 2920 7083 20 / 2010 - 10 - Printed in Belgium

www.atlascopco.com