Atlas Copco G 2 User manual

INSTRUCTION BOOK
OIL-INJECTED ROTARY SCREW COMPRESSORS
G 2, G 3, G 4, G 5

Atlas Copco
Oil-injected rotary screw compressors
G 2, G 3, G 4, G 5
From following serial No. onwards: WUX 200 511
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.
2019 - 11
No. 2920 7170 31
www.atlascopco.com

Table of contents
1 General description........................................................................................................4
1.1 INTRODUCTION...................................................................................................................................4
1.2 OPERATING PRINCIPLE.........................................................................................................................8
1.3 CONTROL PANEL ............................................................................................................................. 11
1.4 ELECTRICAL DIAGRAMS......................................................................................................................12
1.5 PROTECTION OF THE COMPRESSOR......................................................................................................13
1.6 AIR DRYER......................................................................................................................................15
2 Installation.....................................................................................................................16
2.1 INSTALLATION PROPOSAL................................................................................................................... 16
2.2 DIMENSION DRAWINGS.......................................................................................................................18
2.3 ELECTRICAL CONNECTIONS ................................................................................................................20
2.4 PICTOGRAPHS................................................................................................................................. 20
3 Operating instructions................................................................................................. 22
3.1 INITIAL START-UP..............................................................................................................................22
3.2 STARTING....................................................................................................................................... 24
3.3 STOPPING.......................................................................................................................................26
3.4 TAKING OUT OF OPERATION................................................................................................................27
4 Maintenance..................................................................................................................28
4.1 PREVENTIVE MAINTENANCE SCHEDULE..................................................................................................28
4.2 DRIVE MOTOR .................................................................................................................................29
4.3 OIL SPECIFICATIONS..........................................................................................................................30
4.4 OIL, FILTER AND OIL SEPARATOR CHANGE............................................................................................. 31
4.5 PDX/DDX FILTER CHANGE (OPTION).................................................................................................. 33
4.6 STORAGE AFTER INSTALLATION........................................................................................................... 33
4.7 SERVICE KITS.................................................................................................................................. 34
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4.8 DISPOSAL OF USED MATERIAL............................................................................................................. 34
5 Adjustments and servicing procedures..................................................................... 35
5.1 AIR FILTER......................................................................................................................................35
5.2 COOLERS....................................................................................................................................... 36
5.3 SAFETY VALVE ................................................................................................................................36
5.4 BELTS MAINTENANCE........................................................................................................................ 37
6 Problem solving............................................................................................................39
7 Technical data...............................................................................................................42
7.1 READINGS ON CONTROL PANEL........................................................................................................... 42
7.2 ELECTRIC CABLE SIZE....................................................................................................................... 43
7.3 SETTINGS FOR OVERLOAD RELAY AND FUSES.........................................................................................43
7.4 REFERENCE CONDITIONS AND LIMITATIONS............................................................................................ 44
7.5 COMPRESSOR DATA..........................................................................................................................44
8 Instructions for use...................................................................................................... 46
9 Guidelines for inspection.............................................................................................47
10 Pressure equipment directives................................................................................... 48
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1 General description
1.1 Introduction
Introduction
G 2, G 3, G 4 and G 5 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.
The control panel at the front includes a pressure gauge and a start/stop switch. See section
Control panel for details.
Available versions:
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.
The compressor is mounted on top of an air receiver.
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G 2 Pack, tank mounted
Reference Description
1 Control panel
AO Air outlet
AR Air receiver
Dm2 Condensate drain on air receiver
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G 2 Full-Feature, tank mounted (front view)
Reference Description
1 Control panel
AR Air receiver
DR Dryer
Dm2 Manual condensate drain valve
OT Oil separator tank
Co Oil cooler
OF Oil filter
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G 2 Full-Feature, tank mounted (rear view)
Reference Description
AO Air outlet connection
AR Air receiver
DR Dryer
E Compressor element
OS Oil separator
OF Oil filter
AF Air filter
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1.2 Operating principle
Pack units
Flow diagram, tank mounted Pack units
Air flow
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).
Oil flow
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) 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.
Cooling
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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 by means of a manual drain valve.
Full-Feature
Flow diagram, tank mounted Full-Feature units
Air flow
The compressed air flows from the receiver and the dryer to the outlet (AO).
Oil flow
See above
Cooling
The dryer (DR) of Full-Feature versions has a separate cooling fan and an automatic condensate
drain.
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Regulating system
The main components of the regulating system are:
• 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. Blowoff valve (Y1) opens and the pressure in the air/oil separator is released. When
the working pressure decreases to the preset minimum pressure, the contacts of the pressure
switch close and the motor restarts. Blowoff valve Y1 closes and compressed air supply is
resumed.
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1.3 Control panel
Control panel
Reference Designation Function
1 Main 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. Also overload
protection (only for IEC).
2 Dryer ON/OFF button To start and stop the dryer (Full-Feature units only)
3 ON/OFF switch To start and stop the compressor.
Hm Hour meter Indicates the total running time.
Gpa Working pressure The white pointer indicates the actual working pressure.
H1 Lamp Lights up when the machine is operating.
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1.4 Electrical diagrams
Service diagram - IEC - 3 ph DOL
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Service diagram - IEC - 3 ph Y-D
Text on image
(1) Main switch and fuses to be installed by customer.
1.5 Protection of the compressor
Safety valve on the compressor
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Safety valve on the air receiver (tank-mounted units)
Reference Designation Function
IG
See also section
Electrical diagrams
Motor overload relay To shut down the compressor in case the motor current
is too high.
TSH
See also section
Electrical diagrams
Temperature shut-down
switch
To shut down the compressor if the temperature at the
outlet of the compressor element is too high.
SV Safety valve To protect the air outlet system if the outlet pressure
exceeds the opening pressure of the valve.
After tripping of the temperature protection: switch off the voltage and depressurise. Check and
remedy. See section Problem solving. Wait a few minutes to let the machine cool down.
To reset and restart, switch on the voltage and press the red reset button after unscrewing its
cover: the machine will restart.
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1.6 Air dryer
Air dryer (Full-Feature compressors)
Wet compressed air (B) enters the dryer and flows through a heat exchanger (2) where
refrigerant evaporates, withdrawing heat from the air. The cold air then flows through a
condensate trap (1) which separates condensate from the air. The condensate is automatically
drained and this is regulated by a timer. The dried air is then discharged from the dryer.
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2 Installation
2.1 Installation proposal
Outdoor/altitude operation
If the compressor is installed outdoors or if the ambient temperature can be below 0˚C (32˚F),
precautions must be taken. In this case, and also if operating at high altitude, consult Atlas
Copco.
Moving/lifting
Transport by a pallet truck
To prevent a tank-mounted model from falling over during transport by a pallet truck:
push the forks underneath the air receiver and place a wooden beam (1) (cross-section
approx. 4 x 6 cm / 1.6 x 2.4 in) through the supports on both sides of the receiver. While
holding the compressor, slowly lift the forks until the receiver is secured between the
beams.
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Installation proposal
Installation proposal, tank mounted units
Ref. Description/recommendation
1 Isolating switch, compressor
2 Isolating switch, dryer
3 Front panel, compressor
4 Dryer
(1) Minimum 1.5 m
(2) Space for maintenance, minimum 2 m
(3) Single-phase dryer supply
(4) Three-phase screw compressor supply
(5) The power cable should be protected so that it complies with local codes
Step Action
1 Install the compressor on a solid, level floor suitable for taking the weight.
The recommended minimum distance between the top of the unit and the ceiling is 1.5 m (58.5
in).
The minimum distance between the wall and the back of the compressor must be 200 mm (7.8
in).
The pipes between a floor- mounted compressor and air receiver are hot.
2 Position of the compressed air outlet valve.
Close the valve.
Connect the air net to the valve.
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Step Action
3 The pressure drop over the air delivery pipe can be calculated as follows:
Δp = (L x 450 x Qc1.85) / (d5 x P), with
d = Inner diameter of the pipe in mm
Δp = Pressure drop in bar (recommended maximum: 0.1 bar (1.5 psi))
L = Length of the pipe in m
P = Absolute pressure at the compressor outlet in bar
Qc = Free air delivery of the compressor in l/s
4 Ventilation: the inlet grids and ventilation fan should be installed in such a way that any
recirculation of cooling air to the compressor or dryer is avoided.
5 Lay out the condensate drain flexible from timer drain (T) as well as the flexible from condensate
drain valve (4) towards a drain collector. The drain pipes to the drain collector must not dip into
the water of the drain collector.
2.2 Dimension drawings
Tank mounted Pack units
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