Atlas Copco GX 2 EP, GX 5 EP, GX 3 EP, GX 4 EP, GX 7 EP Instruction Book
Atlas Copco
Oil-injected rotary screw compressors
GX 2 EP, GX 3 EP, GX 4 EP, GX 5 EP, GX 7 EP
Instruction book
Atlas Copco
Oil-injected rotary screw compressors
GX 2 EP, GX 3 EP, GX 4 EP, GX 5 EP, GX 7 EP
From following serial No. onwards: CAI 544 242
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.
2014 - 05
No. 2920 7105 31
Replaces No. 2920 7105 30
www.atlascopco.com
Table of contents
1 Safety precautions..........................................................................................................4
1.1 SAFETY ICONS...................................................................................................................................4
1.2 GENERAL SAFETY PRECAUTIONS............................................................................................................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 INTRODUCTION...................................................................................................................................9
2.2 AIR FLOW.......................................................................................................................................11
2.3 OIL SYSTEM....................................................................................................................................14
2.4 COOLING SYSTEM.............................................................................................................................16
2.5 REGULATING SYSTEM........................................................................................................................17
2.6 CONTROL PANEL .............................................................................................................................19
2.7 ELECTRICAL DIAGRAMS......................................................................................................................20
2.8 PROTECTION OF THE COMPRESSOR......................................................................................................27
2.9 AIR DRYER......................................................................................................................................29
3 Installation.....................................................................................................................30
3.1 INSTALLATION PROPOSAL...................................................................................................................30
3.2 DIMENSION DRAWINGS.......................................................................................................................33
3.3 ELECTRICAL CONNECTIONS ................................................................................................................37
3.4 PICTOGRAPHS.................................................................................................................................38
4 Operating instructions.................................................................................................40
4.1 INITIAL START-UP..............................................................................................................................40
4.2 STARTING.......................................................................................................................................42
4.3 STOPPING.......................................................................................................................................44
Instruction book
2 2920 7105 31
4.4 TAKING OUT OF OPERATION................................................................................................................46
5 Maintenance..................................................................................................................48
5.1 PREVENTIVE MAINTENANCE SCHEDULE..................................................................................................48
5.2 DRIVE MOTOR .................................................................................................................................49
5.3 OIL SPECIFICATIONS..........................................................................................................................50
5.4 OIL, FILTER AND SEPARATOR CHANGE .................................................................................................50
5.5 STORAGE AFTER INSTALLATION...........................................................................................................52
5.6 SERVICE KITS..................................................................................................................................52
5.7 DISPOSAL OF USED MATERIAL.............................................................................................................52
6 Adjustments and servicing procedures.....................................................................53
6.1 AIR FILTER......................................................................................................................................53
6.2 COOLERS.......................................................................................................................................54
6.3 SAFETY VALVE ................................................................................................................................54
6.4 BELT SET EXCHANGE AND TENSIONING ................................................................................................55
7 Problem solving............................................................................................................57
8 Technical data...............................................................................................................60
8.1 READINGS ON CONTROL PANEL...........................................................................................................60
8.2 ELECTRIC CABLE SIZE.......................................................................................................................60
8.3 SETTINGS FOR OVERLOAD RELAY AND FUSES.........................................................................................61
8.4 REFERENCE CONDITIONS AND LIMITATIONS............................................................................................63
8.5 COMPRESSOR DATA..........................................................................................................................63
9 Instructions for use......................................................................................................67
10 Guidelines for inspection.............................................................................................68
11 Pressure equipment directives...................................................................................69
12 Declaration of conformity............................................................................................70
Instruction book
2920 7105 31 3
1 Safety precautions
1.1 Safety icons
Explanation
Danger for life
Warning
Important note
1.2 General safety precautions
1. The operator must employ safe working practices and observe all related work safety requirements and
regulations.
2. If any of the following statements does not comply with the applicable legislation, the stricter of the two
shall apply.
3. Installation, operation, maintenance and repair work must only be performed by authorized, trained,
specialized personnel. The personnel should apply safe working practices by use of personal protection
equipment, appropriate tools and defined procedures.
4. The compressor is not considered capable of producing air of breathing quality. For air of breathing quality,
the compressed air must be adequately purified according to the applicable legislation and standards.
5. Before any maintenance, repair work, adjustment or any other non-routine checks:
• Stop the compressor
• Press the emergency stop button
• Switch off the voltage
• Depressurize the compressor
• Lock Out - Tag Out (LOTO):
• Open the power isolating switch and lock it with a personal lock
• Tag the power isolating switch with the name of the service technician.
• On units powered by a frequency converter, wait 10 minutes before starting any electrical repair.
• Never rely on indicator lamps or electrical door locks before maintenance work, always disconnect
and check with measuring device.
If the machine is equipped with an automatic restart after voltage failure function and if this
function is active, be aware that the machine will restart automatically when the power is
restored if it was running when the power was interrupted!
6. 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.
7. The owner is responsible for maintaining the unit in safe operating condition. Parts and accessories shall
be replaced if unsuitable for safe operation.
8. It is prohibited to walk or stand on the unit or on its components.
Instruction book
4 2920 7105 31
1.3 Safety precautions during installation
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.
Precautions during installation
1. The machine must only be lifted using suitable equipment 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. The unit is designed for indoor use. If the unit is installed outdoors, special precautions must be taken;
consult your supplier.
3. In case the device is a compressor, place the machine 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.
4. Any blanking flanges, plugs, caps and desiccant bags must be removed before connecting the pipes.
5. 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.
6. In case the device is a compressor, the aspirated air must be free of flammable fumes, vapors and particles,
e.g. paint solvents, that can lead to internal fire or explosion.
7. In case the device is a compressor, arrange the air intake so that loose clothing worn by people cannot be
drawn in.
8. Ensure that the discharge pipe from the compressor to the aftercooler or air net is free to expand under
heat and that it is not in contact with or close to flammable materials.
9. No external force may be exerted on the air outlet valve; the connected pipe must be free of strain.
10. 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 depressurized and that the electrical isolating
switch is open, locked and labelled with a temporary warning before any maintenance or repair. As a
further safeguard, persons switching on or off 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 start equipment.
11. Air-cooled machines must be installed in such a way that an adequate flow of cooling air is available and
that the exhausted air does not recirculate to the compressor air inlet or cooling air inlet.
12. 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 compressor.
13. 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.
14. In multiple compressor systems, manual valves must be installed to isolate each compressor. Non-return
valves (check valves) must not be relied upon for isolating pressure systems.
15. 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.
Instruction book
2920 7105 31 5
16. Piping or other parts with a temperature in excess of 70˚C (158˚F) and which may be accidentally touched
by personnel in normal operation must be guarded or insulated. Other high temperature piping must be
clearly marked.
17. 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.
18. If the ground is not level or can be subject to variable inclination, consult the manufacturer.
19. If the device is a dryer and no free extinguishing system is present in the air net close to the dryer, safety
valves must be installed in the vessels of the dryer.
Also consult following safety precautions: Safety precautions during operation and Safety
precautions during maintenance.
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
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.
Precautions during operation
1. Never touch any piping or components of the compressor during operation.
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, vapors or
particles.
5. Never operate the machine below or in excess of its limit ratings.
6. Keep all bodywork doors shut during operation. The doors may be opened for short periods only, e.g. to
carry out routine checks. Wear ear protectors when opening a door.
On compressors without bodywork, wear ear protection in the vicinity of the machine.
7. People staying in environments or rooms where the sound pressure level reaches or exceeds 80 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
• No leaks occur
• 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 repair, free
of wear or abuse
Instruction book
6 2920 7105 31
• Air cooling filters of the electrical cabinet are not clogged
9. If warm cooling air from compressors is used in air heating systems, e.g. to warm up a workroom, take
precautions against air pollution and possible contamination of the breathing air.
10. On water-cooled compressors using open circuit cooling towers, protective measures must be taken to
avoid the growth of harmful bacteria such as Legionella pneumophila bacteria.
11. Do not remove any of, or tamper with, the sound-damping material.
12. 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.
13. Yearly inspect the air receiver. Minimum wall thickness as specified in the instruction book must be
respected. Local regulations remain applicable if they are more strict.
Also consult following safety precautions: Safety precautions during installation and Safety
precautions during maintenance.
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.
1.5 Safety precautions during maintenance or repair
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.
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
start equipment.
7. Close the compressor air outlet valve and depressurize the compressor 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 or perform any operation involving heat near the oil system. Oil tanks must be completely
purged, e.g. by steam cleaning, before carrying out such operations. Never weld on, or in any way modify,
pressure vessels.
Instruction book
2920 7105 31 7
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 vapour 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. If removed, check that the coupling guard of the compressor drive shaft has been
reinstalled.
17. Every time the separator element is renewed, examine the discharge pipe and the inside of the oil separator
vessel for carbon deposits; if excessive, the deposits should be removed.
18. Protect the motor, air filter, electrical and regulating components, etc. to prevent moisture from entering
them, e.g. when steam cleaning.
19. Make sure that all sound-damping material and vibration dampers, e.g. damping material on the bodywork
and in the air inlet and outlet systems of the compressor, is in good condition. If damaged, replace it by
genuine material from the manufacturer to prevent the sound pressure level from increasing.
20. Never use caustic solvents which can damage materials of the air net, e.g. polycarbonate bowls.
21. 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.
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.
Instruction book
8 2920 7105 31
2 General description
2.1 Introduction
Introduction
GX 2 EP, GX 3 EP, GX 4 EP, GX 5 EP and GX 7 EP are air-cooled, single-stage, oil-injected screw
compressors, driven by an electric motor.
The compressors are belt driven.
The compressors are enclosed in sound-insulating bodywork.
An easy-to-operate control panel is provided, including the start/stop switch and the emergency stop button.
A cabinet housing the regulator, pressure switch and motor starter is integrated into the bodywork.
Pack versions do not include an air dryer.
Full-Feature versions are fitted with an air dryer (DR). The dryer removes moisture from the compressed air
by cooling the air to near the freezing point and automatically draining the condensate.
Floor-mounted model
The compressor is installed directly on the floor.
The floor-mounted model is available as Pack version only.
GX 5 Pack EP, floor-mounted
Ref. Description
1 Control panel
Instruction book
2920 7105 31 9
Tank-mounted model
Tank-mounted units are supplied with an air receiver of 200 l (52.80 US gal / 44 Imp gal / 7 cu.ft) and are
available in Pack and Full-Feature version.
GX 5 FF EP, tank-mounted
Ref. Description
1 Control panel
AO Air outlet
AR Air receiver
Dm2 Condensate drain valve, air receiver
SV Safety valve
DR Integrated dryer
Instruction book
10 2920 7105 31
2.2 Air flow
Pack
Air flow, floor-mounted Pack units
Instruction book
2920 7105 31 11
Air flow, tank-mounted Pack units
Air drawn in through air filter (AF) and open inlet valve (IV) is compressed in compressor element (E).
Compressed air and oil flow into oil separator/tank (OT) where most of the oil is removed by centrifugal
action. The remaining oil is removed by oil separator (OS). The air flows to the outlet (AO) via minimum
pressure valve (Vp).
Instruction book
12 2920 7105 31
Full-Feature
Air flow, GX tank-mounted Full-Feature units
Air drawn in through air filter (AF) and open inlet valve (IV) is compressed in compressor element (E).
Compressed air and oil flow into oil separator/tank (OT) where most of the oil is removed by centrifugal
action. The remaining oil is removed by oil separator (OS). The air is discharged via minimum pressure valve
(Vp), air receiver (AR) and dryer (DR) towards the air outlet (AO).
Instruction book
2920 7105 31 13
2.3 Oil system
GX Pack
Instruction book
14 2920 7105 31
GX Full-Feature
Air pressure in the oil separator tank (OT) forces the oil from the tank to compressor element (E) via oil cooler
(Co) and oil filter (OF). Compressed air and oil flow into oil separator/tank (OT) where most of the oil is
separated from the air by centrifugal action. The remaining oil is removed by oil separator (OS) and returns
to the oil circuit via a separate line. The minimum pressure valve (Vp - see section Air flow) ensures a minimal
pressure in the tank, required for oil circulation under all circumstances.
The oil circuit has a thermostatic bypass valve (BV). The oil cooler is bypassed until the oil is warm.
Instruction book
2920 7105 31 15
2.4 Cooling system
Pack units
Instruction book
16 2920 7105 31
Full-Feature units
A fan on the drive motor shaft provides air flow to cool the oil and the other components of the compressor.
On tank-mounted compressors, the air receiver is used as air cooler. The condensate is drained manually.
The dryer (DR) of Full-Feature versions has a separate cooling fan and an automatic condensate drain (see
also section Air dryer).
2.5 Regulating system
GX 2 up to GX 5
The main components of the regulating system are:
Instruction book
2920 7105 31 17
• Pressure switch (PSR11)
• Blow-off valve (Y1)
The contacts of pressure switch (PSR11) open and close at preset pressures. During loaded operation, the
contacts are closed: the motor is running.
When the working pressure reaches the upper limit, the contacts of the pressure switch open: the motor stops.
Blow-off valve (Y1) opens and the pressure in the air/oil separator is released. When the working pressure
decreases to the pre-set minimum pressure, the contacts of the pressure switch close and the motor restarts.
Blow-off valve Y1 closes and compressed air supply is resumed.
GX 7
Detail view of unloader assembly (UA)
The main components of the regulating system are:
• Pressure switch: contact opens and closes at preset pressure limits. See also section Protection of the
compressor.
• Unloader (UA), including inlet valve (IV) and unloading valve (UV).
• Loading solenoid valve (Y1).
As long as the working pressure is below the preset maximum, the solenoid valve is energised, allowing
control air to the unloader: the inlet valve opens completely and the unloading valve closes completely. The
compressor will run fully loaded (100% output).
When the working pressure reaches the maximum limit, the solenoid valve is de-energised, venting the control
air: the inlet valve closes completely and the unloading valve opens completely. The compressor will run
unloaded (0% output).
• If the compressor keeps running unloaded for an uninterrupted period of 240 seconds, it will be stopped.
• If the pressure reaches the minimum pressure level before the 240 seconds are reached, the compressor
will automatically start running loaded again.
The compressor will automatically restart when the net pressure drops to the minimum limit.
Instruction book
18 2920 7105 31
2.6 Control panel
Control panel GX Pack
Control panel GX Full Feature
Reference Designation Designation
1 Main switch -
emergency switch
To power the unit. Also used to stop the compressor in the event
of an emergency and to reset the thermal overload of the electric
motor by switching it to 0 and back to I.
3 Dryer ON/OFF switch (Only on Full-Feature units)
Gpa Pressure gauge The pointer indicates the actual working pressure.
Hm Hour meter Indicates the total running time.
H1 Lamp Lights up when the machine is operating.
S Switch Start/Stop switch (GX 2 EP up to GX 5 EP)
Load/unload switch (GX 7 EP)
Instruction book
2920 7105 31 19
2.7 Electrical diagrams
Service diagram GX 2 - IEC - 1 ph
Service diagram GX 2 up to GX 5 - IEC - 3 ph DOL
Instruction book
20 2920 7105 31
Service diagram GX 2 up to GX 5 - IEC - 3 ph Y-D
Single phase dryer - 230 V 50/60 Hz
Instruction book
2920 7105 31 21
Loading...