Atlas Copco Railway compressors

GAR11-15-18-22-30

Instruction Book

• Copyright 2000, Atlas Copco Airpower n.v., Antwerp, Belgium.

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 meets the requirements for instructions specified by the machinery directive
98/37/EC and is valid for CE as well as non-CE labelled machines.

No. 2920 1411 01 www.atlascopco.com

Registration code: APC GAR/'99 / 38 / 997

Replaces No. 2920 1411 00

2000-05

*2920141101*
 Instruction book

This instruction book describes how to handle the machines to ensure safe operation, optimum efficiency and long service life.

Read this book before putting the machine into operation to ensure correct handling, operation and proper maintenance from the
beginning. The maintenance schedule comprises measures for keeping the machine in good condition.

Keep the book available for the operator and make sure that the machine is operated and that maintenance is carried out according
to the instructions. Record all operating data, maintenance performed, etc. in an operator's logbook available from Atlas Copco.
Follow all relevant safety precautions, including those mentioned on the cover of this book.

Repairs must be carried out by trained personnel from Atlas Copco who can be contacted for any further information.

In all correspondence always mention the type and the serial number, shown on the data plate.

For all data not mentioned in the text, see sections "Preventive maintenance schedule" and "Principal data".

The company reserves the right to make changes without prior notice.

CONTENTS
Page Page
1 Leading particulars . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.3 Oil and oil filter change . . . . . . . . . . . . . . . . . . . . 12
1.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.4 Oil separator change . . . . . . . . . . . . . . . . . . . . . . . 12
1.1.1 Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.5 Part numbers of oil, separator and filters . . . . . . . 12
1.1.2 Oil system . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.6 Storage after installation . . . . . . . . . . . . . . . . . . . . 13
1.1.3 Cooling system . . . . . . . . . . . . . . . . . . . . . . 3 4.7 Air filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2 Operation of the unloading/loading system . . . . . . 3 4.8 Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2.1 Unloading . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.9 Safety valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2.2 Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.10 Temperature gauge/switch . . . . . . . . . . . . . . . . . . 13
1.3 Operation of the start/stop system . . . . . . . . . . . . . 7 4.11 By-pass valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.3.1 Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.2 Stopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5 Overhauling instructions . . . . . . . . . . . . . . . . . . . . . . 14
1.4 Air outlet temperature switch . . . . . . . . . . . . . . . . . 7 5.1 Replacement and overhauling instructions for
compressor element, gearbox, coupling housing
2 Compressor installation . . . . . . . . . . . . . . . . . . . . . . . . 7 and shaft seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1 Installation directives . . . . . . . . . . . . . . . . . . . . . . . 7 5.2 Replacement of oil temperature gauge/switch . . . 14
2.2 Dimension drawings . . . . . . . . . . . . . . . . . . . . . . . . 8 5.3 Replacement of air inlet valve/unloading valve . . 14

3 Operating instructions . . . . . . . . . . . . . . . . . . . . . . . . 10 6 Problem solving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.1 Initial start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Principal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3 Stopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.1 Reading on gauge . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.4 Taking out of operation at end of compressor 7.2 Setting of safety valve . . . . . . . . . . . . . . . . . . . . . . 16
service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.3 Compressor specifications . . . . . . . . . . . . . . . . . . 16
7.3.1 Reference conditions . . . . . . . . . . . . . . . . . 16
4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.3.2 Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1 Preventive maintenance schedule for the 7.3.3 Specific data . . . . . . . . . . . . . . . . . . . . . . . 16
compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.4 Conversion list of SI units into US/British units . 16
4.2 Oil specifications . . . . . . . . . . . . . . . . . . . . . . . . . 11

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1 LEADING PARTICULARS Oil stop valve (Vs) prevents the compressor element from
flooding with oil when the compressor is stopped. The valve
is opened by element outlet pressure when the compressor is
1.1 General description started.
GAR are stationary, air-cooled, single-stage, oil-injected screw A heater (Hro) can be provided in the oil sump if operating in
compressors. They are designed to feed brake systems and low ambient temperatures (below -25 degrees celsius) or in
other pneumatic appliances of trains or trams with compressed high relative humidity conditions.
air. Two versions are available:

GAR A for floor-mounting inside locomotives or rail cars. 1.1.3 Cooling system (Figs. 1.1 up to 1.4)
GAR B for mounting underneath locomotives or rail cars.
The cooling system comprises air cooler (Ca) and oil cooler
GAR11-30 units comprise the compressor element, an enclosed (Co). The cooling air flow is generated by fan (FN). The
cooling fan, an oil separator, air and oil cooler, gearbox and cooling fan is mounted on the shaft of the motor. The cooling
flexible coupling. air is drawn in through the coolers and leaves the compressor
unit via the bottom, left or right side depending on the fan
The compressor element houses two rotors mounted in a special housing orientation.
bearing arrangement. The module can be driven by a motor
through the flexible coupling. Oil is injected to lubricate and
seal the rotors as well as to absorb compressor heat.
1.2 Operation of the unloading/loading
system (Fig. 1.3)
1.1.1 Air flow (Figs. 1.1 up to 1.4)
1.2.1 Unloading
Air drawn through filter (AF) and open inlet valve (IV) into
compressor element (E) is compressed. Compressed air and If the air consumption is less than the air output of the compressor,
oil flow through check valve (CV) into air receiver/oil separator the net pressure increases. When the net pressure reaches the
(OT). The air is discharged through minimum pressure valve unloading pressure, solenoid valve (Y1) is de-energized. The
(Vp1) and air cooler (Ca). plunger of the valve returns by spring force:

Check valve (CV) prevents backflow of compressed air when 1. The control pressure present in the chambers of loading
the compressor is stopped. plunger (LP) and unloading valve (UV) is vented to
atmosphere via solenoid valve (Y1).
Minimum pressure valve (Vp1) prevents the receiver pressure 2. Loading plunger (LP) moves by spring force causing inlet
from dropping below a minimum pressure, needed for valve (IV) to close the air inlet opening.
lubrication of compressor element (E). 3. Unloading valve (UV) is opened by receiver pressure. The
pressure from air receiver/oil separator (OT) is released
towards unloader (UA).
1.1.2 Oil system (Figs. 1.1 up to 1.4) 4. The pressure is stabilized at a low value. A small amount
of air is kept drawn in through valve (BV2) and is blown to
In air receiver/oil separator (OT), most of the oil is removed the unloader.
from the air/oil mixture centrifugally. The balance is removed
by oil separator element (OS). The lower part of the receiver Air output is stopped (0 %), the compressor runs unloaded.
serves as oil tank.

Air pressure forces the oil from the oil tank through oil cooler 1.2.2 Loading
(Co) and filter (OF) to compressor element (E).
When the net pressure decreases to the loading pressure, solenoid
The oil system is provided with a by-pass valve (BV1). When valve (Y1) is energized. The plunger of solenoid valve (Y1)
the oil temperature is below 75 degrees celsius, by-pass valve moves against spring force:
(BV1) shuts off the oil supply from oil cooler (Co). Air pressure
forces the oil from oil tank (OT) through oil filter (OF) and 1. Control pressure is fed from air receiver/oil separator (OT)
oil stop valve (Vs) to compressor element (E). Oil cooler (Co) via solenoid valve (Y1) to loading plunger (LP) and
is by-passed. unloading valve (UV).
2. Unloading valve (UV) closes the air blow-off opening.
By-pass valve (BV1) starts opening the oil supply to cooler Loading plunger (LP) moves against spring force causing
(Co) when the oil temperature has increased to the above- inlet valve (IV) to open fully.
mentioned value.
Air output is resumed (100 %), the compressor runs loaded.

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AF Air filter
BV1 Oil cooler by-pass valve
Vp1 SV Ca Co Ca Air cooler
Co Oil cooler
CV Check valve
DP1 Oil drain plug
E Compressor element
Y1 FC Oil filler plug
1 FN Fan
IV Gl Oil sight-glass
OS M1 IV Air intake valve
M1 Drive motor
FC OF Oil filter
OS Oil separator element
OT Air receiver/oil separator
SV Safety valve
50743F T1 Temperature gauge/switch
Vp1 Minimum pressure valve
OT CV/Vs E FN Vs Oil stop valve
Y1 Solenoid valve
1 Oil pipe
Fig. 1.1 General view 2 Oil pipe

Figs. 1.1 and 1.2 General views

Co Ca

Vp1
AF
2 IV
T1
E
M1
CV/
Vs
50742F

OF BV1 GL DP1 OT FC OS

Fig. 1.2 General view

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AF Air filter Gl Oil sight-glass SV Safety valve

BV1 Oil cooler by-pass valve Hro Oil heater (optional) T1 Temperature gauge/switch
BV2 By-pass valve IV Air intake valve UA Unloader
Ca Air cooler LP Loading plunger UV Unloading valve
Co Oil cooler M1 Drive motor Vp1 Minimum pressure valve
CV Check valve OF Oil filter Vs Oil stop valve
DP1 Oil drain plug OS Oil separator element V1 Oil drain valve
E Compressor element OT Air receiver/oil separator V2 Air outlet valve
FC Oil filler plug P1 Vacuum switch, air filter Y1 Solenoid valve
FN Fan (optional)

Fig. 1.3 Unloading/loading system, compressor loaded

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AF Air filter FN Fan P1 Vacuum switch, air filter (optional)

BV1 Oil cooler by-pass valve Gl Oil sight-glass SV Safety valve
Ca Air cooler Hro Oil heater (optional) T1 Temperature gauge/switch
Co Oil cooler IV Air intake valve Vp1 Minimum pressure valve
CV Check valve M1 Drive motor Vs Oil stop valve
DP1 Oil drain plug OF Oil filter V1 Oil drain valve
E Compressor element OS Oil separator element V2 Air outlet valve
FC Oil filler plug OT Air receiver/oil separator Y1 Solenoid valve

Fig. 1.4 Start/stop system, compressor loaded

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1.3 Operation of the start/stop system 2 COMPRESSOR INSTALLATION

(Fig. 1.4)
Moving/lifting
The compressor can be moved using the fixation points of the
1.3.1 Starting frame. Make sure that the chains cannot damage the
compressor. The lifting equipment must be placed in such a
When the net pressure decreases to the loading pressure, the way that the compressor will be lifted perpendicularly. Lift
compressor drive motor (M1) is started and solenoid valve (Y1) smoothly and avoid twisting.
is energized.

After starting of the motor, air intake valve (IV) is opened fully 2.1 Installation directives
by the pressure difference over the valve created by the rotating
rotors. Air output is resumed (100 %), the compressor runs 1. The compressor must be installed in such way that rain,
loaded. snow, dust, etc. cannot enter or block the system. The intake
and cooling air must be as clean as possible.
The plunger of the solenoid valve moves against spring force, 2. Recirculation of cooling air to the compressor must be
closing the blow-off line. avoided.
3. If operating in dusty surroundings, install a pre-filter
upstream of the air intake filter.
4. If supplied, install service indicator lamps for the air intake
filter and oil separator and a pressure gauge on the control
board. Integrate the air outlet temperature switch in an
1.3.2 Stopping alarm/shut-down circuit (see section 1.4).
5. Check that the electrical connections correspond to the local
If the air consumption is less than the air output of the codes. Check the connections for correct tightness. The
compressor, the net pressure increases. When the net pressure installation must be earthed and protected against short
reaches the unloading pressure, drive motor (M1) is stopped circuits by fuses of the inert type in all phases. An isolating
and solenoid valve (Y1) is de-energized. switch must be installed near the compressor.
6. Provide an air outlet valve in order to isolate the compressor.
Air intake valve (IV) moves by spring force closing the air Close the valve. Connect the air net to the valve.
inlet opening. Air output is stopped (0 %). 7. Stick labels on obvious places on the compressor, warning
the operator that the compressor is automatically controlled
The plunger of the solenoid valve returns by spring force, and may be started without warning.
opening the blow-off line. The pressure from air receiver/oil
separator (OT) is released through the solenoid valve into the
housing of air intake valve (IV).

1.4 Air outlet temperature switch

(T1-Fig. 1.2)

The temperature switch is connected to the electrical installation

to warn the operator if the outlet temperature of the compressor
element reaches 105 degrees celsius or to shut down the
compressor if the temperature reaches 120 degrees celsius.

The temperature switch has an indicator scale with three

pointers; a white one, indicating the temperature at the outlet
of the compressor element, a green one indicating the warning
setting and a red one indicating the shut-down setting of the
switch.

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2.2 Dimension drawings

Fig. 2.1 Dimension drawing for compressor with load/unload system

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Fig. 2.2 Dimension drawing for compressor with start/stop system

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3 OPERATING INSTRUCTIONS 3.2 Starting

1. Check the oil level. The oil level must be between the middle
3.1 Initial start-up and the top of sight-glass (Gl-Fig. 1.2). If the level does
not exceed the middle, add oil. See sections 4.2 , 4.3 and
Safety 4.5.
The operator must apply all relevant safety precautions, 2. Switch on the power and start the compressor.
including those mentioned in this book. 3. Open the air outlet valve.

Remark
Consult section 2 for the installation directives and dimension 3.3 Stopping
drawings. 1. Stop the compressor.
2. Close the air outlet valve and switch off the power.
Start-up
1. Check the oil level. The oil level must be between the middle
and the top of sight-glass (Gl-Fig. 1.2). If the level does 3.4 Taking out of operation at end of
not exceed the middle, add oil. See sections 4.2, 4.3 and compressor service life
4.5.
2. Check the drive motor and the fan for correct rotation At the end of the service life of the compressor, proceed as
direction. When facing the motor drive end, the correct follows:
rotation direction is anti-clockwise. 1. Stop the compressor and close the air outlet valve.
Switch on the power. Start the compressor and stop it 2. Switch off the power and disconnect the compressor from
immediately. Check the rotation while the compressor is the mains.
coasting to a stop. 3. Depressurize the compressor.
3. Start and run the compressor for a few minutes. Check that 4. Shut off and depressurize the part of the air net which is
the compressor operates normally. connected to the outlet valve. Disconnect the compressor
air outlet pipe from the air net.
5. Drain the oil.

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4 MAINTENANCE
Attention
Before carrying out any maintenance or repair on the
compressor, stop the compressor and switch off the power.
Close the air outlet valve and depressurize the air system. Apply
all relevant safety precautions, including those mentioned in
this book.

4.1 Preventive maintenance schedule for

the compressor 1)
Attention
Atlas Copco offers several types of Service contracts, relieving
you of all preventive maintenance work. For more details,
consult Atlas Copco.
The schedule comprises a summary of the maintenance
instructions. Read the related section before taking maintenance
measures.
In servicing, replace all removed gaskets, O-rings and washers.
The "longer interval" checks must also include the "shorter
interval" checks.

Period 2) Running See See Operation

hours 2) section note

Daily -- 3.2 4 Check oil level (Gl) before starting

3-monthly -- 4.9 -- Operate safety valve (SV)

" 500 4.8 -- Check coolers (Co/Ca); clean if necessary
" 500 4.5/4.7 1/2 Inspect air filter element (AF)

Yearly -- 4.9 -- Have safety valve (SV) tested

" -- 4.10 -- Have the temperature shut-down function tested
" 4000 4.3/4.5 2/4 Change oil and replace oil filter

2-Yearly 4000 4.5/4.7 1/2 Replace air filter element (AF)

" 4000 4.4/4.5 3 Have oil separator element (OS) replaced

Notes
1. More frequently when operating in a dusty atmosphere. Replace damaged or heavily contaminated elements.
2. Use genuine Atlas Copco filters.
3. Or when the pressure drop over the separator exceeds 1 bar. If supplied, the pressure drop can be checked by the pressure
gauge of the Dp switch when the compressor is running with a stable working pressure.
4. Use Atlas Copco Roto-H Fluid.

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Recommendation
It is recommended to check the hold-down bolts, nuts, pipe connections, air intake system connections, etc. for tightness after the
first 100 hours of operation, and then annually.

Recommended tightening torques for general applications:

Thread size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M5 M6 M8 M10 M12 M16 M20

Hexagon screws, bolts, nuts (strength class 8.8) . . . Nm 5 8 20 41 73 185 355
Socket screws (strength class 12.9) . . . . . . . . . . . . . Nm 8 14 34 70 120 315 600

Important
In case of aluminium parts, the tightening torques must be reduced to 2/3 of the upper values.

4.2 Oil specifications 4.4 Oil separator change (Fig. 1.1)

It is strongly recommended to use Atlas Copco Roto-H Fluid. 1. If the oil and oil filter are also to be changed, first carry out
steps 1 up to 4 of section 4.3.
For use of other oils, contact Atlas Copco. 2. Stop the compressor, close the compressor outlet valve and
depressurize the oil system by opening oil filler plug (FC)
one turn to permit any pressure to escape. Switch off the
4.3 Oil and oil filter change (Figs. 1.1 up to power.
1.4) 3. Remove the oil separator cover (6 bolts).
4. Remove oil separator element (OS).
1. Run the compressor until warm. Stop it and close the 5. Clean the oil separator compartment (if necessary).
compressor outlet valve. Switch off the power. Wait a few If the oil separator compartment is wet on the inside
minutes. Depressurize the oil system by opening oil filler (moisture), the compressor element may be operating at
plug (FC) one turn to permit any pressure to escape. too low temperatures. Consult Atlas Copco.
2. Remove plug (DP1). Drain the oil by opening drain valve If the bottom cup of the oil separator element is
(V1). Collect the oil in a collector and deliver it to the completely filled with oil, the oil scavenging line is clogged.
local oil collection service. Close the valve and reinstall Inspect the parts and replace, if necessary.
the plug. Drain the cooler, if possible. 6. Fit a new oil separator element.
3. Remove the oil filter (OF). 7. Refit the cover. Use two new O-rings.
4. Clean the filter seat on the manifold. Oil the gasket of the 8. If the oil and the oil filter are changed: carry out steps 5 and
new element. Screw the element into place until the gasket 6 of section 4.3. Check for leaks.
contacts its seat, then tighten by hand (approx. half a turn).
5. Remove plug (FC) and fill receiver/oil separator (OT) with
oil until the level reaches the filler neck. Take care that no 4.5 Part numbers of oil, separator and
dirt drops into the system. Fit and tighten plug (FC). filters
6. Run the compressor for a few minutes. Stop the compressor
and wait a few minutes to allow the oil to settle. Use genuine spare parts only. The part numbers to order filters
Depressurize the system by opening oil filler plug (FC) one from Atlas Copco are:
turn to permit any pressure to escape. Remove filler plug
(FC) and fill with oil until the level reaches the filler neck. Oil filter 1613 6105 00
Reinstall and tighten plug (FC). Open the compressor outlet Air filter 1613 9215 00
valve. Oil separator element 1613 7502 00
Roto-H 18 l can 2908 8505 00
Roto-H 209 l drum 2908 8504 00

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4.6 Storage after installation gauge.

6. The valve should not leak until the opening pressure is
If the compressor is stored without running from time to time, reached (maximum allowed tolerance is 0.5 bar).
protective measures must be taken. Consult Atlas Copco. 7. If the valve does not open at the pressure specified in section
7.2, consult Atlas Copco or replace the valve.

4.7 Air filter (AF-Fig. 1.2)

4.10 Temperature gauge/switch (T1)
Inspecting
If the cartridge is excessively dirty, the change interval should The temperature switch has 3 pointers: the white pointer
be adapted. Consult Atlas Copco. Always replace dirty or indicates the actual temperature at the outlet of the compressor
damaged elements. element, the green pointer is pre-set at the alarm temperature
and the red pointer is set at the shut-down temperature. Check
Replacing the switch while the compressor is running.
1. Stop the compressor. Switch off the power. Release the
clips and remove the cover. 1. To check the warning level, move the green pointer by
2. Unscrew the nut and take out the filter element. means of the special key until it passes the white pointer.
3. Remove the dust from the cover. Exactly at this moment, the alarm indication on the
4. Fit the new filter element. conductor’s main panel should light up.
5. Refit the cover. Observe the indication “TOP” (if 2. To check the shut-down level, move the red pointer by
applicable). means of the special key until it passes the white pointer.
Exactly at this moment, the compressor must stop
automatically.
4.8 Coolers 3. After this test, adjust the green pointer to 105 degrees celsius
and the red pointer to 120 degrees celsius.
Keep the coolers clean to maintain the cooling efficiency. 4. Replace the gauge/switch, if necessary.

Remove any dirt from the coolers with a fibre brush. Never
use a wire brush or metal objects. Then clean by air jet in 4.11 By-pass valve (BV1-Fig. 1.2)
reverse direction of normal flow. If it is necessary to wash the
coolers with a cleansing agent, consult Atlas Copco. 1. When the oil temperature is below 50 degrees celsius, start
the compressor. Measure the temperature of pipe (1-Fig.
1.1), while observing the oil temperature on temperature
4.9 Safety valve (SV-Fig. 1.1) gauge (T1).
2. This pipe should remain more or less cold until the oil
Operating temperature reaches approx. 75 degrees celsius.
Operate the safety valve by unscrewing the cap one turn and 3. Replace the by-pass valve if it opens too quickly. Observe
retightening it or by pulling the valve lifting lever, depending the correct direction of mounting.
on the type of valve.

Testing
Safety valves can be tested in the workshop for correct opening
pressure.

Important
No adjustments are allowed. Never run the compressor
without safety valve.

1. Stop the compressor. Close the outlet valve and switch off
the power. Open plug (FC-Fig. 1.1) one turn to permit any
pressure to escape.
2. Remove the safety valve and replace it by a tested one, so
that the compressor may be restarted.
3. Fit the valve to a pipe to which an accurate pressure gauge Footnotes chapter 4
is fitted.
4. Connect the pipe to a depressurized part of the compressed 1) Use only authorized parts. Any damage or malfunction caused
air net via a pressure regulator. by the use of unauthorized parts is not covered by Warranty or
5. Pressurize the valve gradually while observing the pressure Product Liability.
2) Whichever interval comes first.

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5 OVERHAULING INSTRUCTIONS 5.2 Replacement of temperature gauge/

switch
Attention
1. Apply all relevant safety precautions, including those 1. Remove the gauge/switch (T1-Fig. 1.2). Disconnect the
mentioned in this book. electrical connections from the switch. Remove the
2. Before carrying out any maintenance or repair, stop the temperature sensor from the check valve housing.
compressor and switch off the power. Close the air outlet 2. Fit the gauge/switch in the opposite order.
valve and depressurize the air system.
3. When handling hot parts, special heat-resistant gloves must
be used. 5.3 Replacement of air inlet valve/unloading
valve

1. Remove the wiring connector from the solenoid valve.

2. Remove the piping connections.
5.1 Replacement and overhauling instruc- 3. Remove the air inlet valve/unloading valve.
tions for compressor element, gearbox, 4. Fit the new valve in the opposite order.
coupling housing and shaft seal

1. If the compressor element or the gearbox parts are to be

replaced, run the compressor until warm (if possible), stop
the compressor and close the air outlet valve. Depressurize
and drain the oil (see section 4.3).
2. Make sure that the parts to be dismantled are cooled down
sufficiently. Remove the compressor module from the
locomotive.
3. Loosen the motor cables in the motor connecting box and
put the cables aside (if applicable).
4. Loosen the pipe couplings of the Dp switch and the vacuum
switch (if supplied).
5. Loosen the support brackets of both switches (if supplied)
and remove the switches together with the bracket.
6. After removing the bolts which connect fan housing and
gearbox, the motor, together with the fan housing, can be
removed. Support the compressor element if necessary.
7. If the compressor element is to be removed from the
gearbox, dismount the non-return valve or unloader from
the compressor element inlet. Disconnect the scavenge pipe.
Remove the pipe from between the air receiver and the check
valve. Remove the pipe from between the check valve/oil
stop valve housing and the thermostat housing. Unscrew
the 8 bolts fixing the compressor element to the gear casing.
Remove the compressor element from the gearbox. Replace
the compressor element if necessary.
8. If the shaft seal is to be replaced, the gear shaft must be
taken out of the gearbox. Remove the shaft seal from the
gearbox housing and remove the bushing from the gear shaft.
Heat the new bushing to 100 degrees celsius and fit it to the
shaft. Fit the new shaft seal into the housing, using Loctite
242 (Nutlock) and a suitable pressing tool. Wipe off excess
Loctite. Take care not to damage the seal lips. Press the
shaft again into the gearbox housing, using a press.
9. Inspect all parts for wear. Replace all damaged parts.
Always use new gaskets, O-rings, etc. Refit all parts in the
opposite order.
10. When the compressor element or the gearbox parts have
been replaced: also inspect the oil cooler (clean or replace
if necessary) and change the oil, oil filter and separator
element.

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6 PROBLEM SOLVING 5 Excessive oil consumption; oil carry-over through

discharge line
a Oil level (Gl) too high
Attention a Check for overfilling. Release pressure and drain oil to
1. Apply all relevant safety precautions, including those correct level
mentioned in this book. b Incorrect oil causing foam
2. Before carrying out any maintenance or repair, stop the b Change to correct oil
compressor and switch off the power. Close the air outlet c Oil separator element (OS) defective
valve and depressurize the air system. c Have element checked. Replace, if necessary

6 Compressor does not blow off and cannot restart

Mechanical faults and suggested remedies (Figs. 1.1 up to a Solenoid valve (Y1) stuck in closed position
1.4) a Check solenoid valve, replace if necessary. Also check
control pipe to valve for leakage

1 Compressor starts running, but does not deliver air

a Solenoid valve (Y1) out of order
a Have valve inspected
b Air intake valve (IV) stuck
b Consult Atlas Copco
c Minimum pressure valve (Vp1) leaking (when net is
depressurized)
c Have valve checked

2 Compressor air output or pressure below normal

a Air consumption exceeds air output of compressor
a Check equipment connected
b Choked air inlet filter element (AF)
b Replace filter element
c Air intake valve (IV) does not fully open
c Have valve checked
d Oil separator element (OS) clogged
d Have element replaced
e Air leakage
e Check and correct as necessary
f Safety valve (SV) leaking
f Have valve replaced

3 Safety valve (SV) blows

a Minimum pressure valve (Vp1) malfunctioning
a Have valve checked
b Oil separator element (OS) clogged
b Have element replaced
c Safety valve (SV) out of order
c Have valve replaced
d Pressure switch not functioning
d Check and replace if necessary

4 Element outlet or air outlet temperature above normal

a Insufficient cooling air or cooling air temperature too high
a Check for cooling air restriction or improve ventilation of
compressor compartment. Avoid recirculation of cooling
air. If installed, check capacity of compressor room fan
b Oil level too low
b Check and correct as necessary
c Coolers (Co/Ca) clogged
c Clean cooler block
d By-pass valve (BV1) malfunctioning
d Have valve tested

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 Instruction book

7 PRINCIPAL DATA
7.1 Reading on gauge
Ref. Compressor element outlet temperature
Reading Approx. 60 degrees celsius above cooling air inlet temperature (during continuous operation)

7.2 Setting of safety valve

Opening pressure, safety valve (SV) . . . . . . . . . . . . . . . . . bar(e) 11.5

7.3 Compressor specifications

7.3.1 Reference conditions

Air inlet pressure (absolute) . . . . . . . . . . . . . . . . . . . . . . . . bar(a) 1

Air inlet temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . degrees celsius 20
Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . % 0
Working pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . bar(e) 9.5

7.3.2 Limitations

Maximum working pressure . . . . . . . . . . . . . . . . . . . . . . . . bar(e) 10

Minimum working pressure . . . . . . . . . . . . . . . . . . . . . . . . bar(e) 4
Maximum air inlet temperature . . . . . . . . . . . . . . . . . . . . . degrees celsius 50
Minimum air inlet temperature . . . . . . . . . . . . . . . . . . . . . . degrees celsius -40

7.3.3 Specific data

Compressor type GAR GAR GAR GAR GAR GAR GAR GAR GAR GAR
11 15 18 22 30 11 15 18 22 30

Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . Hz 50 50 50 50 50 60 60 60 60 60
Outlet temperature, approx. . . . . . . . . . . . . . celsius 28 32 35 28 32 28 32 35 28 32
Motor shaft speed . . . . . . . . . . . . . . . . . . . . . r/min 1500 1500 1500 3000 3000 1800 1800 1800 3600 3600
Shaft power input . . . . . . . . . . . . . . . . . . . . . kW 10.4 14.1 16.8 21.3 30.2 9.6 13.5 18.7 20.9 28.7
Oil capacity . . . . . . . . . . . . . . . . . . . . . . . . . . l 9 9 9 9 9 9 9 9 9 9
Sound pressure 2) at 1 m . . . . . . . . . . . . . . . dB(A) 78 79 80 85 86 80 81 82 89 90
Sound pressure 2) at 4.6 m . . . . . . . . . . . . . . dB(A) 70 71 72 76 77 72 73 74 79 80

7.4 Conversion list of SI units into US/British units

1 bar = 14.504 psi 1 l = 0.220 Imp gal (UK) 1 mbar = 0.401 in water column
1 g = 0.035 oz 1 l = 0.035 cu.ft 1 N = 0.225 lbf
1 kW = 1.341 hp (UK and US) 1 l/s = 2.117 cfm 1 Nm = 0.738 lbf.ft
1 l = 0.264 US gal 1 mm = 0.039 in x degrees celsius = (32 +1.8 x) degrees fahrenheit 1)

Footnotes chapter 7

1) A temperature difference of 1 degree celsius = a temperature difference of 1.8 degrees fahrenheit.

2) According to CAGI PNEUROP under free field conditions.

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