Gardner Denver L4-5C Product information sheet

L-SERIES FRAME 0
SINGLE STAGE
BASE-MOUNTED &
TANK-MOUNTED
COMPRESSOR
Original User &
Service Manual
MODELS:
L4-5C
5 & 7.5 HP
4 & 5 kW
13-25-629
Version 03
March 19, 2021

13-25-629 v03 Page 2
MAINTAIN COMPRESSOR RELIABILITY AND PERFORMANCE WITH
GENUINE GARDNER DENVER® COMPRESSOR PARTS AND SUPPORT SERVICES
Gardner Denver®Compressor genuine parts, manufactured to design tolerances, are developed for optimum
dependability, specifically for Gardner Denver compressor systems. Design and material innovations are the result of
years of experience with hundreds of different compressor applications. Reliability in materials and quality assurance
is incorporated in our genuine replacement parts.
Your authorized Gardner Denver Compressor distributor offers all the backup you’ll need. An AirSmart™network of
authorized distributors provides the finest product support in the air compressor industry.
Your authorized distributor can support your Gardner Denver air compressor with these services:
1. Trained parts specialists to assist you in selecting the correct replacement parts.
2. A full line of factory tested compressor lubricants specifically formulated for use in Gardner Denver
compressors.
3. Repair and maintenance kits designed with the necessary parts to simplify servicing your compressor.
Authorized distributor service technicians are factory trained and skilled in compressor maintenance and repair. They
are ready to respond and assist you by providing fast, expert maintenance and repair services.
To Contact Gardner Denver or locate your local distributor:
Visit: www.contactgd.com/compressors
Or
Call: [phone]
INSTRUCTIONS FOR ORDERING REPAIR PARTS
When ordering parts, specify Compressor MODEL, Method of Cooling, HORSEPOWER and SERIAL NUMBER (see
nameplate on unit). The Airend Serial Number is also stamped on top of the discharge bearing carrier casting.
All orders for Parts should be placed with the nearest authorized distributor.
Where NOT specified, quantity of parts required per compressor or unit is one (1); where more than one is required
per unit, quantity is indicated in parenthesis. SPECIFY EXACTLY THE NUMBER OF PARTS REQUIRED.
DO NOT ORDER BY SETS OR GROUPS.
To determine the Right-Hand and Left-Hand side of a compressor, stand at the motor end and look toward the
compressor. Right-Hand and Left- Hand are indicated in parenthesis following the part name, i.e. (RH) and (LH),
when appropriate.

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WARNING –PROHIBITION –MANDATORY LABEL INFORMATION
Gardner Denver Rotary Screw compressors are the result of advanced engineering and skilled
manufacturing. To be assured of receiving maximum service from this machine, the owner must exercise
care in its operation and maintenance. This book is written to give the operator and maintenance
department essential information for day-to-day operation, maintenance and adjustment. Careful
adherence to these instructions will result in economical operation and minimum downtime.
Boxed text formats are used, within this manual, to alert users of the following
conditions:
Safety Labels are used, within this manual and affixed to the appropriate areas of
the compressor package, to alert users of the following conditions:
Indicates a hazard with a high level of risk, which if not avoided, WILL result in death or serious
injury.
Equipment Starts Automatically
Cutting of Finger or Hand Hazard –Rotating
Impeller Blade
Cutting of Finger or Hand Hazard –Rotating Fan
Blade
Health Hazard –Explosive Release of Pressure
High Voltage –Hazard of Shock, Burn, or Death
Present until Electrical Power is Removed
Entanglement of Fingers or Hand/Rotating Shaft

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Indicates a hazard with a medium level of risk which, if not avoided, COULD result in death or
serious injury.
Asphyxiation Hazard –Poisonous Fumes or Toxic Gases in Compressed Air
Indicates a hazard with a low level of risk which, if not avoided, MAY result in a minor or
moderate injury.
Burn Hazard –Hot surface
PROHIBITION/MANDATORY ACTION REQUIREMENTS
Do not Operate Compressor with Guard Removed
Do Not Lift Equipment with Hook –No Lift Point
Handle Package at Forklift Points Only
Lockout Electrical Equipment in De-Energized
State
Loud Noise Hazard –Wear Ear Protection
Read the Operator’s Manual Before Proceeding
with Task

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SAFETY PRECAUTIONS
Safety is everybody’s business and is based on your use of good common sense. All situations or
circumstances cannot always be predicted and covered by established rules. Therefore, use your past
experience, watch out for safety hazards and be cautious. Some general safety precautions are given
below:
Failure to observe these notices will result in injury to or death of personnel.
Keep fingers and clothing away from rotating fan, drive coupling, etc.
Disconnect the compressor unit from its power source, lockout and tagout before working on the
unit –this machine is automatically controlled and may start at any time.
Do not loosen or remove the oil filler plug, drain plugs, covers, the thermostatic mixing valve or
break any connections, etc., in the compressor air or oil system until the unit is shut down and
the air pressure has been relieved.
Electrical shock can and may be fatal.
Perform all wiring in accordance with the National Electrical Code (NFPA-70) and any applicable
local electrical codes. Wiring and electrical service must be performed only by qualified
electricians.
Open main disconnect switch, lockout and tagout and check for voltage before working on the
control.
Failure to observe these notices could result in damage to equipment.
Stop the unit if any repairs or adjustments on or around the compressor are required.
Do not use the air discharge from this unit for breathing, not suitable for human consumption.
An Excess Flow Valve should be on all compressed air supply hoses exceeding 1/2" inside
diameter (OSHA Regulation, Section 1926.302).
Do not exceed the rated maximum pressure values shown on the nameplate.
Do not operate unit if safety devices are not operating properly. Check periodically. Never bypass
safety devices.

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TABLE OF CONTENTS
Maintain Compressor Reliability And Performance With Genuine Gardner Denver Compressor Parts And
Support Services.........................................................................................................................................2
Instructions For Ordering Repair Parts .......................................................................................................2
Warning –Prohibition –Mandatory Label Information ................................................................................3
Safety Precautions...................................................................................................................................... 5
Section 1, General Information ...................................................................................................................7
Section 2, Installation................................................................................................................................ 11
Section 3, Starting & Operating Procedures ............................................................................................. 17
Section 4, Controls & Instrumentation.......................................................................................................22
Section 5, Lubrication. Oil Cooler, Oil Filter & Separator..........................................................................40
Section 6, Heat Exchangers (Oil/Air) ........................................................................................................48
Section 7, Air Filters..................................................................................................................................51
Section 8, Belt Drive System..................................................................................................................... 53
Section 9, Servicing Of Miscellaneous Devices........................................................................................56
Section 10, Tank Mounted Compressor - Total System............................................................................64
Section 11, Maintenance Schedule...........................................................................................................65
Section 12, Troubleshooting ..................................................................................................................... 67
This manual covers the following models:
HP
PSIG
Air Cooled
Parts List
Controller Manual
5 & 7.5
110, 130, 190
L4-5C
13-25-549
ZS1054347

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SECTION 1
GENERAL INFORMATION
Figure 1-1 COMPRESSOR CYCLE
COMPRESSOR - The rotary screw compressor is a single stage, positive displacement rotary machine
using meshing helical rotors to effect compression. Both rotors are supported between high capacity anti-
friction bearings located outside the compression chamber. Roller bearings are used at the inlet end of
the rotors to carry part of the radial loads. Angular contact ball and roller bearings at the discharge end
locate each rotor axially and carry all thrust loads and the remainder of the radial loads.
COMPRESSION PRINCIPLE (Figure 1-1)Compression is accomplished by the main and secondary
rotors synchronously meshing in a one-piece cylinder. The main rotor has five (5) helical lobes 90apart.
The secondary rotor has six (6) matching helical grooves 72apart to allow meshing with main rotor
lobes.
The air inlet port is located on top of the compressor cylinder near the drive shaft end. The discharge port
is near the bottom at the opposite end of the compressor cylinder. Figure 1-1 is an inverted view to show
inlet and discharge ports. The compression cycle begins as the rotors unmesh at the inlet port and air is
drawn into the cavity between the main rotor lobes and the secondary rotor grooves (A). When the rotors
pass the inlet port cutoff, air is trapped in the interlobe cavity and flows axially with the meshing rotors (B).
As meshing continues, more of the main rotor lobe enters the secondary rotor grove, normal volume is
reduced and pressure increases.
Oil is injected into the cylinder to remove the heat of compression and seal internal clearances. Volume
reduction and pressure increase continues until the air/oil mixture trapped in the interlobe cavity by the
rotors passes the discharge port and is released to the oil reservoir (C). Each rotor cavity follows the
same “fill-compress-discharge” cycle in rapid succession to produce a discharge air flow that is
continuous, smooth and shock free.
AIR FLOW IN THE COMPRESSOR SYSTEM (Figure 1-3) Air enters the air filter and passes through the
inlet unloader valve and on into the compression chamber where oil is injected into the air. After
compression, the air/oil mixture passes into the oil reservoir where most of the entrained oil is removed by
velocity change and impingement and drops back into the reservoir. The air and remaining oil then
passes through the air/oil separator. The air then passes through the minimum pressure/check valve, the
after cooler and the optional moisture separator and into the plant air lines.
LUBRICATION, COOLING AND SEALING - Oil is forced by air pressure from the oil reservoir through
the oil cooler, thermostatic mixing valve, and oil filter and discharge into the compressor main oil gallery.
A portion of the oil is directed through internal passages to the bearings and shaft oil seal. The balance
of the oil is injected directly into the compression chamber to remove heat of compression, seal internal
clearances and lubricate the rotors.

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Figure 1-2 COMPRESSOR ILLUSTRATION, EXTERNAL DETAILS
302ECA797-A
(Ref. Drawing)
Page 1 of 2

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Figure 1-3 COMPRESSOR ILLUSTRATION, INTERNAL DETAILS
302ECA797-A
(Ref. Drawing)
Page 2 of 2

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Figure 1-4 COMPRESSOR ILLUSTRATION, TOTAL SYSTEM
(L4-5 Base Model with 120 gallon receiver and XGNC dryer shown)
307ECA804-A
(Ref. Drawing)
Page 1 of 2

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SECTION 2
INSTALLATION
GENERAL - On receipt of the unit, check for any damage that may have been incurred during transit.
Report any damage or missing parts as soon as possible.
Do not electric weld on the compressor or base; bearings can be damaged by
passing of current.
LIFTING UNIT - Proper lifting and/or transporting methods must be used to prevent damage. Unit may
be moved into location by lift truck.
Lift compressor unit under base only. Do not use other places such as motor,
compressor or discharge manifold piping as lifting points.
The eyebolts or lugs provided on the motor are for lifting the motor only and
should not be used to lift any additional weight. All eyebolts must be securely
tightened. When lifting the motor the lifting angle must not exceed 15°. Failure
to observe this warning may result in damage to equipment or personal injury.
Compressor, air/oil reservoir, separator chamber and all piping and tubing may
be at high temperature during and after operation.
LOCATION (Figure 2-1) The compressor must be installed where it is protected from rain, snow and
freezing temperatures, in a clean, well-lighted, well-ventilated area with ample space all around for
maintenance. Select a location that provides a cool, clean, dry source of air. In some cases, it may be
necessary to install the air filter at some distance from the compressor to obtain proper air supply.
AIR-COOLED UNIT - A combination oil/air cooler is supplied as standard equipment on all air-
cooled units. A shaft driven axial fan supplies the ventilation needs for the oil/air cooler and
electric motor cooling (
Figure 1-2). Air is drawn into the unit through the left side panel, over the motor and discharged through
the cooler cores. Do not block the air flow to and from the unit. Allow three and one half (3-1/2) feet to
the nearest obstruction on the control box end of the unit. Allow two (2) feet to the nearest obstruction
above and on other sides of unit.

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For continuous efficiency, the cooler cores must be periodically cleaned with either vacuum or
compressed air. If wet cleaning is required, shield motor and spray on a mild soap solution and flush with
clean water.
NOTICE
Coolers are aluminum; do not use any cleaning solution that is not compatible
with aluminum. Use of improper solution may result in damage to the cooler.
Figure 2-1 TYPICAL COMPRESSOR ROOM
Minimum Air Flow* For Compressor
And Cooling (Cubic Feet/Minute)
Air Cooled
All Models
785 CFM
* 80F Inlet Air
Figure 2-2 AIR FLOW CHART
FOUNDATION - The rotary screw compressor requires no special foundation, but should be mounted on
a smooth and solid surface. Whenever possible, install the unit near level. Mounting bolts are not
normally required. However, installation conditions such as piping rigidity, angle of tilt, or danger of
shifting from outside vibration or moving vehicles may require the use of mounting bolts and shims to
provide uniform support for the base. Belt alignment and tension should be checked after installation.
(For information on belt alignment and tension, Section 8).
OIL SUMP / OIL COOLER DRAIN –Sump oil is drained from single valve and flexible hose assembly
accessible from removable right-side panel. Oil cooler charge is drained from a single plugged connection
on the lower, left-hand side of the core (see Figure 1-3).

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ENCLOSURE - The compressor, electric motor, oil cooler and after cooler are mounted inside the
enclosure.
Service panels are provided for maintenance access. Be sure to allow enough space around the unit for
the panels to be removed. Any of the enclosure panels may be removed by opening the latch and lifting it
up slightly.
Do not operate the compressor with the fan and belt guard removed. Exposed
fan and belts may cause injury to personnel.
The enclosure doors and panels must be closed and latched while the
compressor is operating. Failure to close and latch the doors and panels will
cause high temperature shutdowns.
Figure 2-3 COLD WEATHER INSTALLATION, TYPICAL

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INSTALLATION FOR COLD WEATHER OPERATION
Figure 2-3, It is recommended that the unit be installed inside a shelter that will be heated to
temperatures above freezing (32°F, 0°C). This will eliminate many of the problems associated with
operating units in cold climates, such as freezing in control lines and downstream of the cooler.
Refer to Engineering Data Sheet 13-9-411 for the advantages of using the heat recovered from rotary
compressors. This heat recovery could easily pay for an adequate shelter for the unit.
When the unit must be installed in an outdoors installation and/or exposed to ambient temperatures below
freezing (32°F, 0°C), contact Gardner Denver for recommendations.
When using a Total System with a compressed air dryer option, refer to Section 10 for details.
Remember unsheltered (outside) installations should be avoided whenever possible. Installation next to
a heated building, where enough heat can be used to keep the compressor room above freezing, will
save many complications in the operation and installation of the unit.
AUXILIARY AIR RECEIVER –When using the base compressor package, an auxiliary air receiver is not
required if the piping system is large and provides sufficient storage capacity to prevent rapid cycling.
When used, an air receiver should be of adequate size, provided with a relief valve of proper setting, a
pressure gauge and a means of draining condensate
OPTIONAL MOISTURE SEPARATOR/TRAP - The unit can be provided with an optional stand-alone
combination moisture separator and trap that is field-installed downstream of the after cooler.
CONTROL PIPING - Control piping is not necessary since the rotary screw unit is factory wired and piped
for the control system specified.
INLET LINE - The filter is close-coupled to the compressor intake flange, thus no inlet line is used or
recommended.
DISCHARGE SERVICE LINE –For a stand-alone compressor unit, the discharge service line
connection is provided at the outlet of the field installed water separator, which in turn is located at the
lower right hand side of the after cooler core.
For a compressor unit integrated into the Total System, the discharge service line connection is
provided at the outlet of the dryer bypass loop (when dryer options is furnished) or at the outlet of the
receiver vessel.
A hand operated valve, (air service valve) and a separate (swing-type) check valve must be installed
between the unit and the customer’s air system. If a fast operating valve such as a ball valve is used, it
must be closed slowly to give the intake valve time to shut and keep the discharge pressure from spiking.
The controller has an automatic start/stop sequence built in. You do NOT need
to close the air service valve. Closing the air service valve on start-up or prior to
shutdown will cause rapid cycling, and could cause a high pressure shutdown.
When piping two or more rotary screw units on a common discharge line, each unit shall be isolated by
the check valve in the unit discharge line.
If a rotary screw and a reciprocating compressor are piped to a common discharge line, an air receiver
must be located between the two units.

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Discharge air used for breathing will cause severe injury or death.
Consult filtration specialists for additional filtration and treatment equipment to
meet health and safety standards.
ELECTRICAL WIRING - Standard Units –The stand alone compressor package is factory wired for all
connections from the starter to the motor, for the horsepower and voltage specified on the order. The
standard unit is supplied with totally enclosed motors and a UL Type 1 (NEMA 1) starter and controls
enclosure. See “Location” paragraph in Section 2, for distance to the nearest obstruction on the control
box side of the package.
The overload settings are to be selected based on motor nameplate full load amperage.
Perform all wiring in accordance with the National Electrical Code (NFPA-70) and any applicable local
electrical codes. Wiring must be performed only by qualified electricians.
Electrical shock can cause injury or death. Open main disconnect switch,
lockout and tag out before working on control box.
When the compressor unit is integrated into a Total System and the optional compressed air dryer is
furnished, the latter shall be provided with a separate source of electrical power.
Electrical Wire Sizing - A certified electrician familiar with National Electric Codes and applicable local
codes shall size the electrical power wires serving the compressor package. Refer to Figure 2-4 for a
summary of maximum package current draw values.
Package Power
Voltage
Max Current Draw, Amps
5 / 7.5 (3 Phase)
575
10.8
460
13.2
380
16.0
230
26.4
208
29.1
5 / 7.5 (1 Phase)
230
35.0
Figure 2-4 Electrical Wiring Sizing Data

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GROUNDING - Equipment must be grounded in accordance with Section 250 of the National Electrical
Code.
Failure to properly ground the compressor package could result in injury or
death. Install ground wiring in accordance with the National Electrical Code
and any applicable local codes.
MOTOR LUBRICATION - The Hebei type H112-2 motors used with this compressor package have
sealed bearings which have been greased at the factory and require no re-greasing during their
operational life. These motors do not have injection or drain ports for re-greasing.

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SECTION 3
STARTING & OPERATING PROCEDURES
PRESTART-UP INSTRUCTIONS - A new unit received from the factory has been prepared for shipping
only. Do not attempt to operate the unit until checked and serviced as follows:
1. Compressor Oil - The oil level must be checked before starting the unit and every 8 hours of
operation. For instructions on checking the oil and the proper oil level, refer to “Oil level gauge”,
Section 5.
Do not mix different type oils. Standard Unit is shipped filled with Gardner Denver AEON 4000
lubricant which is suitable for the first 4000 hours under normal operating conditions. Other AEON
lubricants are available. Check the decal on the reservoir to be sure which lubricant is in the
machine.
NOTICE
Regular maintenance and replacement at required intervals of the oil filter, air
filter and air/oil separator is necessary to achieve maximum service and
extended drain intervals of AEON 4000 lubricant. Use only genuine Gardner
Denver filters designed and specified for this compressor.
Always stop the unit and release air pressure before removing oil filler plug.
Failure to release pressure may result in personal injury or death.
2. Air Filter - Inspect the air filter to be sure it is clean and tightly assembled. Refer to Section 7 for
complete servicing instructions. Be sure the inlet line, if used, is tight and clean.
Package Inlet Filter (
3. Figure 1-2) Inspect the Pre-Filter to be sure it is clean. Refer to Section 7 for complete servicing
instructions
4. Piping –Refer to Section 2, “Discharge Service Line” and make sure all piping meets all
recommendations.
5. Electrical - Check the wiring diagrams furnished with the unit to be sure it is properly wired. See
Figures 4-2 to 4-14 for general wiring diagrams and Section 2 for “Electrical Wiring”.
6. Grounding - Unit must be properly grounded according to Section 250 of the National Electrical
Code.
7. When using a Total System with a compressed air dryer option, refer to Section 10 for details.

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Failure to properly ground the compressor package could result in controller
malfunction.
8. V-Belt System - Refer to Section 8 for detailed instruction to unpack and check the alignment of the
belt system.
The motor jacking hardware must be re-configured, the main motor carrier
bracket removed, belts engaged, and the belt sheaves alignment checked prior to
compressor operation. Failure to do so will prevent compressor operation and/or
component damage.
9. Rotation - Check for correct motor rotation by, in quick succession, starting and stopping the
compressor system. Note that the controller can also detect reverse motor rotation by sensing a
vacuum pressure, but this may damage the compressor by prolonged operation under reverse
rotation. If motor reverse rotation is confirmed, follow the appropriate “lockout/tagout” procedure to
isolate the package from the electrical grid, reverse any two motor leads connected to the package
or motor, restore electrical power to the package, and re-check rotation.
Operation with incorrect motor rotation can damage equipment and cause oil
eruption from the compressor inlet. When checking motor rotation, induce
minimum rotation (less than one revolution if possible). Never allow motor to
reach full speed.
The compressor unit’s direction of rotation must be checked every time the
compressor package or its main motor is reconnected to the power supply.
Electrical shock can cause injury or death. Open main disconnect switch,
lockout and tagout before working on control box.

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10. For your convenience, the following excerpt from the Controller manual is presented to assist in
programming the basic operating parameters. However, we strongly recommend you read the
Controller manual before attempting operating the compressor package.
Figure 3-1 GD Pilot Controller Layout and Main Screen
Controller Hardware layout.
oSee Fig 3-1 for the layout of the main screen and input devices.
oThe ( I ) key switches unit on.
oThe (O) key switches unit off.
oThe (Ө) key enters a selection and clears a fault.
oThe (↑↓) keys, hit simultaneously, call up or exit a menu/submenu.
oThe (↑) key navigates to a previous submenu/menu or increases a parameter value.
oThe (↓) key navigates to a next submenu/menu or decreases a parameter value.
oDisplay info (1st row): AE discharge temp and press, MPV discharge press (permanent).
oDisplay info (2nd row): Menus. Total Running Hrs. default menu.
oDisplay info (3rd row): Status, Fault and Warning messages. Load status default menu.
Setting the Cut-out Pressure
oNavigate to the [Control Menu] by pressing simultaneously the (↑↓) keys.
oNavigate to the [Cut out] submenu with the (↓) key. Adjust the pressure to a value between 1
to 6 psig above the desired operating pressure by using the (↑↓) keys.
Setting the Cut-in Pressure
oNavigate to the [Cut in] submenu with the (↓) key. Adjust the pressure to a value at least 1 to
6 psig below that of the desired operating pressure by using the (↑↓) keys.
oFor 1 phase models which use a variable frequency drive (for narrow speed modulation), the
“Cut-in” submenu is replaced with a “Target” submenu. In this case, adjust the pressure to a
value equal to the desired operating pressure.
Selecting the operating mode
oNavigate to the [Automatic Operation] submenu with the (↓) key, this is the recommended
mode to use until you become familiar with the Controller manual and other operating modes
available.

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Operation at excessive discharge air pressure can cause personal injury or
damage to equipment. Do not adjust the operating discharge air pressure above
the maximum stamped on the unit nameplate.
11. Enclosure - Check for damaged panels or doors. Check all screws and latches for tightness. Be
sure doors are closed and latched.
The compressor starts and stops automatically. Automatic restarting can cause
injury or death. Open, lockout and tagout main disconnect and any other
circuits before servicing the unit.
The enclosure doors must be closed and latched to keep the compressor
package from overheating when the compressor is running.
After an emergency stop, be sure that the pressure in the air/oil reservoir is less
than 5 psig. Wait one minute or more before restarting.
The controller has an automatic start/stop sequence built in. You DO NOT need
to close the air service valve. Closing the air service valve on start-up or prior to
shutdown will cause rapid cycling, and could cause a high pressure shutdown.