Frick RXB PLUS Owner's manual

ROTARY SCREW COMPRESSOR UNITS
WITH
MICROPROCESSOR CONTROL
ALL REFRIGERANTS
THIS MANUAL CONTAINS RIGGING, ASSEMBLY, START-UP, AND
MAINTENANCE INSTRUCTIONS. READTHOROUGHLY BEFORE BE-
GINNING INSTALLATION. FAILURE TO FOLLOW THESE INSTRUC-
TIONS COULD RESULT IN DAMAGE OR IMPROPER OPERATION
OF THE UNIT.
Form S70-101 IOM (JAN 2000)
INSTALLATION - OPERATION - MAINTENANCE
File: SERVICE MANUAL - Section 70
Replaces: S70-101 IOM (APR 96)
Dist: 3, 3a, 3b, 3c

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION - OPERATION - MAINTENANCE
S70-101 IOM
Page 2
GENERAL INFORMATION
Preface .............................................................................. 3
Design Limitations ............................................................. 3
Job Inspection ................................................................... 3
Transit Damage Claims ..................................................... 3
Compressor/Unit Identification .......................................... 3
INSTALLATION
Foundation......................................................................... 4
Handling and Moving......................................................... 4
Skid Removal .................................................................... 5
Motor Mounting.................................................................. 5
Compressor/Motor Coupling Installation ........................... 5
Coupling Alignment Procedure.......................................... 6
Hot Alignment of Compressor/Motor ................................. 8
Checking Motor/Compressor Rotation .............................. 8
Holding Charge and Storage............................................. 8
Compressor Oil.................................................................. 8
Oil Charge ......................................................................... 8
Oil Heater .......................................................................... 8
Liquid Injection Oil Cooling................................................ 9
Dual Dip Tube Method ....................................................... 9
Level Control Method......................................................... 9
Water-Cooled Oil Cooling................................................ 10
Thermosyphon Oil Cooling.............................................. 10
Economizer - High Stage................................................. 12
Electrical.......................................................................... 13
Motor Starter Package..................................................... 13
Current Transformers (CT) Ratios ................................... 14
Minimum Burden Ratings ................................................ 14
Battery Backup ................................................................ 14
OPERATION
General Information......................................................... 15
Microprocessor Control Panel ......................................... 15
Keys and Key Functions .................................................. 16
To Change The Adjustable Setpoints .............................. 18
How To Determine Adjustable Setpoints ......................... 18
Temperature-Pressure Control Program ......................... 22
Lead-Lag (Option) ........................................................... 24
Communications Troubleshooting.................................... 24
How The Microprocessor Works - Summary ................... 25
Multiple Compressor Sequencing.................................... 26
Microprocessor Telecommunications............................... 27
Communications Protocol Specifications ........................ 27
RXB Compressor............................................................. 30
Compressor Lubrication System ..................................... 30
Full-Lube Oil System ....................................................... 30
Compressor Oil Separation System ................................ 30
Compressor Hydraulic System ....................................... 31
Compressor Oil Cooling Systems.................................... 32
Single-Port Liquid Injection.............................................. 32
Dual-Port Liquid Injection ................................................ 33
Liquid Injection Adjustment Procedure............................ 33
TABLE OF CONTENTS
Prestart Checklist ............................................................ 34
Initial Start-up Procedure................................................. 35
Normal Start-up Procedure ............................................. 35
Restarting Unit After Power Failure ................................. 35
MAINTENANCE
Normal Maintenance Operations..................................... 36
Compressor Shutdown and Start-up ............................... 36
General Instructions For Replacing
Compressor Unit Components..................................... 36
Suction Check Valve Bypass Valve.................................. 36
Oil Filter, Single ............................................................... 36
Oil Filter, Dual.................................................................. 37
Strainer, Oil Return.......................................................... 37
Strainer, Oil Pump (Optional)........................................... 37
Strainer, Liquid Injection .................................................. 37
Coalescer Filter Element ................................................. 38
Changing Oil.................................................................... 38
Recommended Maintenance Program............................ 38
Vibration Analysis ............................................................ 39
Oil Quality and Analysis................................................... 39
Motor Bearings ................................................................ 39
Operating Log.................................................................. 39
Maintenance Schedule.................................................... 40
Troubleshooting Guide..................................................... 41
Abnormal Operation Analysis and Correction ................. 41
Troubleshooting The Microprocessor............................... 42
EPROM Memory I/C Chip Replacement ......................... 45
SBC Board Replacement ................................................ 45
Microprocessor Display Replacement ............................. 45
Output Fuse Replacement............................................... 45
Pressure Transducers - Testing ....................................... 45
Pressure Transducer Conversion Data............................ 45
Pressure Transducers - Replacement ............................. 46
Volumizer Potentiometer - Replace/Adjust ...................... 47
Temperature/Pressure Adjustment .................................. 47
Bare Compressor Mounting............................................. 47
Troubleshooting The RXB PLUS:
Compressor ................................................................. 48
Oil Separator System................................................... 48
Hydraulic System ......................................................... 48
Full-Time Pump Systems............................................. 49
Liquid Injection Oil Cooling .......................................... 49
Thermal Expansion Valves .............................................. 50
Temperature Control Valve .............................................. 51
Wiring Diagrams .............................................................. 52
P and I Diagrams............................................................. 58
PROPER INSTALLATION OF ELECTRONIC
EQUIPMENT................................................................ 60
OPERATING LOG........................................................... 63

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION - OPERATION - MAINTENANCE
S70-101 IOM
Page 3
PREFACE
This manual has been prepared to acquaint the owner and
serviceman with the INSTALLATION, OPERATION, and
MAINTENANCE procedures as recommended by Frick for
RXB PLUS Rotary Screw Compressor Units.
It is most important that these units be properly applied to an
adequately controlled refrigeration system. Your authorized
Frick representative should be consulted for his expert guid-
ance in this determination.
Proper performance and continued satisfaction with these
units is dependent upon:
CORRECT INSTALLATION
PROPER OPERATION
REGULAR, SYSTEMATIC MAINTENANCE
To ensure correct installation and application, the equipment
must be properly selected and connected to a properly de-
signed and installed system. The Engineering plans, piping
layouts, etc. must be detailed in accordance with the best
practices and local codes, such as those outlined in ASHRAE
literature.
A refrigeration compressor is a VAPOR PUMP. To be certain
that it is not being subjected to liquid refrigerant carryover, it
is necessary that refrigerant controls are carefully selected
and in good operating condition; the piping is properly sized
and traps, if necessary, are correctly arranged; the suction
line has an accumulator or slugging protection; that load
surges are known and provisions made for control; operating
cycles and defrosting periods are reasonable; and that high
side condensers are sized within system and compressor
design limits.
It is recommended that the entering vapor temperature to the
compressor be superheated to 10OF above the refrigerant
saturation temperature. This ensures that all refrigerant at
the compressor suction is in the vapor state.
DESIGN LIMITATIONS
The compressor units are designed for operation within
the pressure and temperature limits as shown in Frick Pub.
E70-100 SED.
JOB INSPECTION
Immediately upon arrival examine all crates, boxes and
exposed compressor and component surfaces for damage.
Unpack all items and check against shipping lists for any
possible shortage. Examine all items for damage in transit.
TRANSIT DAMAGE CLAIMS
All claims must be made by consignee. This is an ICC re-
quirement. Request immediate inspection by the agent of the
carrier and be sure the proper claim forms are executed.
Report damage or shortage claims immediately to Frick ,
Sales Administration Department, in Waynesboro, PA.
COMPRESSOR and UNIT IDENTIFICATION
Each compressor unit has 2 identification data plates. The
compressor data plate, containing compressor model
and serial number, is mounted on the compressor body.
The unit data plate, containing unit model, serial number,
and Frick sales order number, is mounted on the side of the
motor base.
NOTE: When inquiring about the compressor or unit,
or ordering repair parts, provide the MODEL, SERIAL,
and FRICK SALES ORDER NUMBERS from these data
plates.
UNIT DATA PLATE
COMPRESSOR DATA PLATE

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 4
Installation
FOUNDATION
Each RXB PLUS Rotary Screw Compressor Unit is shipped
mounted on a wood skid which must be removed prior to unit
installation. CAUTION: Allow space for servicing both ends
of the unit. A minimum of 24 inches is recommended.
The first requirement of the compressor foundation is that it
must be able to support the weight of the compressor pack-
age including coolers, oil, and refrigerant charge. Screw
compressors are capable of converting large quantities of
shaft power into gas compression in a relatively small space
and a mass is required to effectively dampen these relatively
high frequency vibrations.
Firmly anchoring the compressor package to a suitable
foundation by proper application of grout and elimination of
piping stress imposed on the compressor is the best insur-
ance for a trouble free installation. Use only the certified
general arrangement drawings from Frick to determine the
mounting foot locations and to allow for recommended clear-
ances around the unit for ease of operation and servicing.
Foundations must be in compliance with local building codes
and materials should be of industrial quality.
The floor should be a minimum of 6 inches of reinforced
concrete and housekeeping pads are recommended. Anchor
bolts are required to firmly tie the unit to the floor. Once the
unit is rigged into place (See HANDLING and MOVING), the
feet must then be shimmed in order to level the unit. The
shims should be placed to position the feet roughly one inch
above the housekeeping pad to allow room for grouting. An
expansion-type epoxy grout must be worked under all areas
of the base with no voids and be allowed to settle with a slight
outward slope so oil and water can run off of the base.
When installing on a steel base, the following guidelines
should be implemented to properly design the system base:
1. Use I-beams in the skid where the screw compressor will
be attached to the system base. They should run parallel to
the package feet and support the feet for their full length.
2. The compressor unit feet should be continuously welded to
the system base at all points of contact, or bolted.
3. The compressor unit should not be mounted on vibration
isolators in order to hold down package vibration levels.
4. The customer’s foundation for the system base should fully
support the system base under all areas, but most certainly
under the I-beams that support the compressor package.
When installing on the upper floors of buildings, extra precau-
tions should be taken to prevent normal package vibration
from being transferred to the building structure. It may be
necessary to use rubber or spring isolators, or a combination
of both, to prevent the transmission of compressor vibration
directly to the structure. However, this may increase package
vibration levels because the compressor is not in contact with
any damping mass. The mounting and support of suction
and discharge lines is also very important. Rubber or spring
pipe supports may be required to avoid exciting the building
structure at any pipe supports close to the compressor pack-
age. It is best to employ a vibration expert in the design of
a proper mounting arrangement.
In any screw compressor installation, suction and discharge lines
should be supported in pipe hangers (preferably within 2 ft. of
vertical pipe run) so that the lines won’t move if disconnected
from the compressor. See table for Allowable Flange Loads.
HANDLING AND MOVING
THIS UNIT MAY BE TOP HEAVY.
USE CARE WHILE HANDLING.
Spreader bars should be used on
both the length and width of the package to prevent
bending of oil lines and damage to the package.
The unit can be moved with rigging, using a crane or forklift.
The recommended method is to insert lengths of 2” pipe
through the lifting holes in the vertical supports (see FIG. 1).
Alternatively, hooks may be used in rigging, inserting them
in the lifting holes (see FIG. 2).
Use CAUTION in locating the lifting ring. If no motor is
mounted, the lifting ring should be moved off center to
the compressor side of the unit because 60 percent of the
weight is toward the compressor end. If a motor is mounted,
appropriate adjustment in the lifting point should be made
to compensate for motor weight. Adjustment of the lifting
point must also be made for any additions to the standard
package, such as an external oil cooler, etc., as the center
of balance will be affected.
FIG. 1 - RECOMMENDED LIFTING METHOD
A licensed architect should be consulted to determine the
proper foundation requirements for any large engine or
turbine drive.
When applying screw compressors at high pressures, the
customer must be prepared for package vibration and noise
higher than the values predicted for normal refrigeration duty.
Proper foundations and proper installation methods are vital;
and even then, sound attenuation or noise curtains may be
required to reduce noise to desired levels.
For more detailed information on Screw Compressor Founda-
tions, please request Frick publication S70-210 IB.
ALLOWABLE FLANGE LOADS
NOZ. MOMENTS (ft-lbf) LOAD (lbf)
SIZE AXIAL VERT. LAT. AXIAL VERT. LAT.
NPS MRM
C ML P VC VL
1 25 25 25 50 50 50
1.25 25 25 25 50 50 50
1.5 50 40 40 100 75 75
2 100 70 70 150 125 125
3 250 175 175 225 250 250
4 400 200 200 300 400 400
5 425 400 400 400 450 450
6 1000 750 750 650 650 650
8 1500 1000 1000 1500 900 900
10 1500 1200 1200 1500 1200 1200
12 1500 1500 1500 1500 1500 1500
14 2000 1800 1800 1700 2000 2000

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 5
FIG. 2 - ALTERNATIVE LIFTING METHOD
The unit can be moved with a forklift by forking under the skid,
or it can be skidded into place with pinch bars by pushing
against the skid. NEVER MOVE THE UNIT BY PUSHING
OR FORKING AGAINSTTHE SEPARATOR SHELL OR ITS
MOUNTING SUPPORTS.
SKID REMOVAL
If the unit is rigged into place the skid can be removed
by taking off the nuts and bolts that are fastening the unit
mounting supports to the skid before lowering the unit onto
the mounting surface.
If the unit is skidded into place, remove the cross members
from the skid and remove the nuts anchoring the unit to the
skid. Using a 5-ton jack under the separator, raise the unit
at the compressor end until it clears the two mounting bolts.
Spread the skid to clear the unit mounting support, then lower
the unit to the surface. Repeat procedure on opposite end.
MOTOR MOUNTING
The following procedure is required only when the motor is
mounted at the job site.
1. Thoroughly clean the motor feet and mounting pads of
grease, burrs, and other foreign matter to ensure firm seat-
ing of the motor.
2. Attach the motor to the base using the bolts and motor-
raising blocks, if required. Bolt snugly through the base.
3. Weld the four kick bolts into place so that they are posi-
tioned to allow movement of the motor feet.
4. Now that the motor has been set, check that the shafts
are properly spaced for the coupling being used. Refer to
the coupling data table for the applicable dimension.
COMPRESSOR/MOTOR COUPLING
INSTALLATION
RXB PLUS units are arranged for direct motor drive and
require a flexible drive coupling to connect the compressor
to the motor. Before installing, perform the following:
1. Inspect the shaft of the motor and compressor to ensure
that no nicks, grease, or foreign matter is present.
2. Inspect the bores in the coupling hubs to make sure that
they are free of burrs, dirt, and grit.
3. Check that the keys fit the hubs and shafts properly.
CH COUPLING – The T.B.Woods Elastomeric CH Coupling
is used in most applications. It consists of two drive hubs
and a loose, gear-type Hytrel Drive Spacer. The split hub is
clamped to the shaft by tightening the clamp screws.Torque
is transmitted from the motor through the elastomeric gear
which floats freely between the hubs. Install as follows:
IT IS MANDATORYTHATTHE COU-
PLING CENTER BE REMOVED
AND THE DIRECTION OF MOTOR
ROTATION BE CONFIRMED BEFORE RUNNING THE
COMPRESSOR. Proper rotation of the compressor shaft
is clockwise looking at the end of the compressor shaft.
FAILURE TO FOLLOW THIS STEP COULD RESULT IN
BACKWARD COMPRESSOR ROTATION WHICH CAN
CAUSE COMPRESSOR FAILURE OR EXPLOSION OF
THE SUCTION HOUSING.
1. Slide one hub onto each shaft as far as possible. It may
be necessary to use a screwdriver as a wedge in the slot to
open the bore before the hubs will slide onto the shafts.
2. Hold the elastomeric gear between the hubs and slide both
hubs onto the gear to fully engage the mating teeth. Make
sure that the keys on the compressor and motor halves of
the coupling are offset 180O(see FIG. 3). Center the gear
and hub assembly so there is equal engagement on both
shafts. Adjust the space between hubs as specified in the
CH Coupling Data Table below.
3. Torque the clamping bolts in both hubs to the torque value
given in the CH Data Table. DO NOT USE ANY LUBRICANT
ON THESE BOLTS.
4. Proceed to Coupling Alignment.
FIG. 3 - COUPLING/SHAFT KEYS INSTALLATION
CH COUPLING DATA TABLE
Coupling Hub
CH Between Shaft Spacing Shaft Engagement Face
Spacing
Clamp Bolt Keyway
Series Min. Max. Min. Max.
Torque (Dry)
Size Setscrew Torque Size
Size In. mm In. mm In. mm In. mm In. mm Ft-Lb Nm Ft-Lb Nm UNC
6 2 50.8 2¾ 69.9 1 25.4 1¹⁵⁄₁₆ 49.2 7/8 22.2 15 20.3 1/4-20 UNC 13 17.6 5/16-18
72⁵⁄₁₆ 58.7 3⁷⁄₁₆ 87.3 1 25.4 2³⁄₁₆ 55.6 1¹⁄₁₆ 27 30 40.7 5/16-24 UNF 13 17.6 5/16-18
82⁹⁄₁₆ 65.1 4 101.6 1¹⁄₁₆ 27 2½ 63.5 1¹⁄₈ 28.6 55 74.6 3/8-24 UNF 13 17.6 5/16-18
93¹⁄₁₆ 77.8 4⁵⁄₈ 117.5 1⁷⁄₁₆ 36.5 3 76.2 1⁷⁄₁₆ 36.5 55 74.6 3/8-24 UNF 13 17.6 5/16-18

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 6
FIG. 1 - ANGULAR MISALIGNMENT
COUPLING ALIGNMENT PROCEDURE
The life of the compressor shaft seal and bearings, as well
as the life of the motor bearings, is dependent upon proper
coupling alignment. Couplings may be aligned at the factory
but realignment MUST ALWAYS be done on the job site
after the unit is securely mounted on its foundation. Initial
alignment must be made prior to start-up and rechecked
after a few hours of operation. Final (HOT) field alignment
can only be made when the unit is at operating temperature.
After final (HOT) alignment has been made and found to be
satisfactory for approximately one week, the motor may be
dowelled to maintain alignment.
NOTE: Frick recommends cold aligning the motor .005”
high. This cold misalignment compensates for thermal
growth when the unit is at operating temperature.
Use dial indicators to measure the angular and parallel shaft
misalignment. Coupling alignment is attained by alternately
measuring angular and parallel misalignment and reposi-
tioning the motor until the misalignment is within specified
tolerances. The following procedure is recommended.
MISALIGNMENT MUST NOT EX-
CEED .004” FOR ALL CH COU-
PLINGS.
ANGULAR ALIGNMENT
1. To check angular alignment, as shown in Fig. 1., attach
dial indicator rigidly to the motor hub. Move indicator stem
so it is in contact with the outside face of compressor hub,
as shown in Fig. 2.
2. Rotate both coupling hubs several revolutions until they
seek their normal axial positions.
Check the dial indicator to be sure that the indicator stem is
slightly loaded so as to allow movement in both directions.
3. Set the dial indicator at zero when viewed at the 12 o’clock
position, as shown in Fig. 2.
4. Rotate both coupling hubs together 180O(6 o’clock posi-
tion), as shown in Fig. 3. At this position the dial indicator will
show TOTAL angular misalignment.
NOTE: The use of a mirror is helpful in reading the indi-
cator dial as coupling hubs are rotated.
5. Loosen motor anchor bolts and move or shim motor to
correct the angular misalignment.
After adjustments have been made for angular misalignment
retighten anchor bolts to prevent inaccurate readings. Repeat
Steps 3 through 5 to check corrections. Further adjustments
and checks shall be made for angular misalignment until the
total indicator reading is within the specified tolerance.
FIG. 2 - DIAL INDICATOR ATTACHED (AT 12 O’CLOCK)
FIG. 3 - DIAL INDICATOR AT 6 O’CLOCK

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 7
PARALLEL ALIGNMENT
6. To check parallel alignment, as shown in Fig. 4, reposition
dial indicator so the stem is in contact with the rim of the
compressor hub, as shown in Fig. 5.
Check the dial indicator to be sure that the indicator stem is
slightly loaded so as to allow movement in both directions.
7. Check parallel height misalignment by setting dial indica-
tor at zero when viewed at the 12 o’clock position. Rotate
both coupling hubs together 180O(6 o’clock position). At this
position the dial indicator will show TWICE the amount of
parallel height misalignment.
8. Loosen motor anchor bolts and add or remove shims under
the four motor feet until parallel height misalignment is within
specified tolerance when anchor bolts are retightened.
CARE MUST BE USED WHEN
CORRECTING FOR PARALLEL
MISALIGNMENTTO ENSURETHAT
THE AXIAL SPACING AND ANGULAR MISALIGNMENT
IS NOT SIGNIFICANTLY DISTURBED.
9. After the parallel height misalignment is within tolerance,
repeat Steps 1 through 5 until angular misalignment is within
specified tolerance.
10. Check parallel lateral misalignment by positioning dial
indicator so the stem is in contact with the rim of the com-
pressor hub at 3 o’clock, as shown in Fig. 6.
Set indicator at zero and rotate both coupling hubs together
180O(9 o’clock position), as shown in Fig. 5.
Adjust parallel lateral misalignment using the motor adjusting
screws until reading is within specified tolerance.
11. Recheck angular misalignment and realign if neces-
sary.
12. Tighten motor anchor bolts and rotate both coupling hubs
together, checking the angular and parallel misalignment
through the full 360Otravel at 90Oincrements. If dial readings
are in excess of specified tolerance, realign as required.
13. When the coupling hubs have been aligned to within
specified tolerance, a recording of the cold alignment must
be made for unit records and usage during hot alignment.
14. Bump the motor to check for correct compressor rotation.
COMPRESSOR ROTATION IS CLOCKWISE WHEN FAC-
ING COMPRESSOR SHAFT (see “CHECKING MOTOR/
COMPRESSOR ROTATION”, page 8). After verification,
install gear or disk drive spacer, as applicable.
15. Install the coupling guard before operating the compres-
sor.
When installing drive spacer, make
sure that hub spacing is within
limits shown on the Coupling Data
Table applicable to the coupling being installed and that
the clamping bolt(s) are properly torqued.
FIG. 4 - PARALLEL MISALIGNMENT
FIG. 5 - DIAL INDICATOR ATTACHED (AT 9 O’CLOCK)
FIG. 6 - DIAL INDICATOR AT 3 O’CLOCK

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 8
HOT ALIGNMENT OF COMPRESSOR/MOTOR
Hot alignments can only be made after the unit has oper-
ated for several hours and all components are at operating
temperatures.
Shut down the unit and quickly affix dial indicator to coupling
motor hub, then take readings of both the face and rim of the
compressor hub. If these readings are within tolerance, record
reading, attach coupling guard, and restart unit. However, if
the reading is not within limits, compare the hot reading with
the cold alignment and adjust for this difference; i.e. if the
rim at 0° and 180° readings indicates that the motor rises
.005" between its hot and cold state, .005" of shims should
be removed from under the motor.
After the initial hot alignment adjustment is made, restart unit
and bring to operating temperature. Shut down and recheck
hot alignment. Repeat procedure unit hot alignment is within
specified tolerance.
INSTALL COUPLING GUARD BE-
FORE OPERATING COMPRES-
SOR.
CHECKING MOTOR/COMPRESSOR
ROTATION
COMPRESSOR ROTATION IS CLOCKWISE WHEN FAC-
ING THE END OF THE COMPRESSOR SHAFT. Under
NO conditions should the motor rotation be checked with
the coupling center installed as damage to the compressor
may result.
HOLDING CHARGE AND STORAGE
Each compressor unit is pressure and leak tested at the Frick
factory and then thoroughly evacuated and charged with dry
nitrogen to ensure the integrity of the unit during shipping
and short term storage prior to installation.
NOTE: Care must be taken when entering the unit to
ensure that the nitrogen charge is safely released.
All units must be kept in a clean, dry location to prevent
corrosion damage. Reasonable consideration must be
given to proper care for the solid state components of the
microprocessor. Unit which will be stored for more than
two months must have the nitrogen charge checked
periodically.
COMPRESSOR
COMPRESSOR UNIT OIL
DO NOT MIX OILS of different
brands, manufacturers, or types.
Mixing of oils may cause exces-
sive oil foaming, nuisance oil level cutouts, oil pressure
loss, gas or oil leakage and catastrophic compressor
failure.
Use of oils other than Frick Oil
must be approved in writing by
Frick engineering or warranty
claim may be denied.
Use of filter elements other than
Frick must be approved in writing
by Frick engineering or warranty
claim may be denied.
The oil charge shipped with the unit is the best suited lu-
bricant for the conditions specified at the time of purchase.
If there is any doubt due to the refrigerant, operating pres-
sures, or temperatures; refer to Frick Pub. E160-802 SPC
for guidance.
OIL CHARGE
The normal charging level is midway in the top sight glass
located midway along the oil separator shell.Normal oper-
ating level is between the top sight glass and bottom
sight glass. The following table gives the approximate oil
charge quantity.
TABLE - BASIC OIL CHARGE (Gal)
MODEL BASIC CHARGE* (GAL.)
12 10
15 10
19 14
24 14
30 17
39 17
50 21
* Add oil volume for external oil cooler, according to cooler
size selected: 6 x 5 TSOC - 4 gal.; 6 x 5 WCOC - 5 gal.; 8 x
5 TSOC - 6-1/2 gal.; and 8 x 5 WCOC - 8 gal.
Add oil by attaching the end of a suitable pressure type
hose to the oil charging valve, located on the top of the oil
separator on the compressor end of the separator. Using a
pressure-type pump and the recommended Frick oil, open
the charging valve and pump oil into the separator.
Oil distillers and similar equipment which act to trap oil must
be filled prior to unit operation to normal design outlet levels.
The same pump used to charge the unit may be used for
filling these auxiliary oil reservoirs.
NOTE: The sight glass, located near the bottom of the
separator shell at the discharge end, should remain
empty when the unit is in operation.The presence of oil
in this end of the vessel during operation indicates liquid
carryover or malfunction of the oil return.
OIL HEATER
Standard units are equipped with a 500 watt oil heater,
providing sufficient heat to maintain the oil temperature for

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 9
LEVEL CONTROL METHOD
The level control method utilizes a float level control on the
receiver to close a solenoid valve feeding the evaporator
when the liquid falls below that amount necessary for 5
minutes of liquid injection oil cooling.
most indoor applications during shutdown cycles to permit
safe start-up. Should additional heating capacity be required
because of unusual environmental condition, contact Frick
Company. The heater is energized only when the unit is not
in operation.
DO NOT ENERGIZE THE HEATER
WHEN THERE IS NO OIL IN THE
UNIT, OTHERWISE THE HEATER
WILL BURN OUT.THE OIL HEATER WILL BE ENERGIZED
WHENEVER 120 VOLT CONTROL POWER IS APPLIED
TOTHE UNIT ANDTHE COMPRESSOR IS NOT RUNNING
UNLESS THE 10 AMP FUSE (1FU) IN THE CONTROL
PANEL IS REMOVED.
LIQUID INJECTION OIL COOLING
The liquid injection system provided on the unit is self-con-
tained but requires the connection of the liquid line sized as
shown in the table and careful insertion of the expansion valve
bulb into the thermowell provided in the separator. High pres-
sure gas is connected through the regulator to the external
port on the liquid injection valve to control oil temperature.
Refer to the liquid injection piping diagram.
NOTE: For booster applications, the high pressure gas
connection must be taken from a high side source (high-
stage compressor discharge).This should be a minimum
3/8" line connected into the solenoid valve provided.This
gas is required by the expansion valve external port to
control oil temperature.
High-stage compressor units may be supplied with single-
port (low Vi) or dual-port (low Vi and high Vi), liquid injection
oil cooling. Single port will be furnished for low compression
ratio operation and dual port for high compression ratio opera-
tion. Booster compressor units use single-port, liquid injection
oil cooling due to the typically lower compression ratios.
The control system on high-stage units with dual-port, liquid
injection oil cooling switches the liquid refrigerant supply to
the high port when the compressor is operating at higher
compression ratios (3.5 Vi and above) for best efficiency.
The following table gives the condensing temperature(s)
with the corresponding maximum evaporator temperature
limit for liquid injection usage and the minimum evaporator
temperature for a single-port application.
TABLE - EVAPORATOR TEMPERATURE with
SINGLE-PORT LIQUID INJECTION
MAXIMUM MINIMUM *
EVAPORATOR EVAP TEMP
CONDENS- TEMPERATURE FOR FOR
ING LIQUID INJECTION SINGLE PORT
TEMP USAGE (LOW Vi)
R-717 R-22 R-717 & R-22
75°F +10°F +5°F -23°F
85°F +25°F +15°F -17°F
95°F +35°F +25°F -11°F
105°F +40°F +35°F - 4°F
* Dual Injection Kit will be shipped by Frick
below these temperatures.
Where low compression ratios (low condensing pressures)
are anticipated, thermosyphon or water-cooled oil cooling
should be used. It is IMPERATIVE that an uninterrupted
supply of high pressure liquid refrigerant be provided to
the injection system at all times. Two items of EXTREME
IMPORTANCE are the design of the receiver/liquid injection
supply and the size of the liquid line. It is recommended that
the receiver be oversized sufficiently to retain a 5 minute
supply of refrigerant for oil cooling. The evaporator supply
must be secondary to this consideration. Two methods of
accomplishing this are shown.
DUAL DIP TUBE METHOD
The dual dip tube method uses two dip tubes in the receiv-
er. The liquid injection tube is below the evaporator tube to
ensure continued oil cooling when the receiver level is low.

RXB PLUS ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-101 IOM
Page 10
OIL COOLER DATA TABLE
SIZE - Inches APPROX
WATER FLOW
COOLER WATER CONN RANGE (GPM)
5 Foot Lengths
6" DIA. 1 NPT 10 – 23
8" DIA. 1-1/4 NPT 35 – 60
*100 ft. liquid line. For longer runs, increase line size ac-
cordingly.
Liquid line sizes and the additional receiver volume (quantity
of refrigerant required for 5 minutes of liquid injection oil
cooling) are given in the following table:
LIQ. LINE SIZE* FLOW LIQUID
REF RXB RATE VOLUME
MODEL PIPE TUBING (lb.) CU.FT.
SCH 80 OD 5 MIN
12 1/2 – 10 .3
15 1/2 – 12.5 .4
HIGH 19 1/2 – 15 .4
STAGE 24 1/2 – 20 .6
R-717 30 1/2 – 25 .7
39 1/2 – 30 8
50 3/4 – 40 1.1
12 3/4 5/8 30 .4
15 3/4 5/8 37.5 .5
HIGH 19 3/4 5/8 45 .6
STAGE 24 3/4 7/8 60 .8
R-22 30 3/4 7/8 75 1.0
39 3/4 7/8 95 1.3
50 1 1 125 1.7
12 1/2 – 2 .1
15 1/2 – 2.5 .1
BOOST- 19 1/2 – 3.5 .1
ER 24 1/2 – 4.5 .1
R-717 30 1/2 – 5.5 .2
39 1/2 – 6.5 .2
50 1/2 –- 8.5 .3
12 3/4 1/2 6 .1
15 3/4 1/2 7 .1
BOOST- 19 3/4 1/2 9 .1
ER 24 3/4 1/2 12 .2
R-22 30 3/4 1/2 14.5 .2
39 3/4 1/2 18 .3
50 3/4 5/8 24 .3
WATER-COOLED OIL COOLING (OPTIONAL)
The shell and tube-type, water-cooled oil cooler is mounted
on the unit complete with all oil piping. The customer must
supply adequate water connections and install the two-way
water regulating valve. It is recommended that (local codes
permitting) the water regulator be installed on the water outlet
connection. Insert the water regulator valve bulb and well in
the chamber provided on the oil outlet connection. Determine
the size of the water-cooled oil cooler supplied with the unit,
then refer to table for the water connection size and water
flow range (GPM). The water supply must be sufficient to
meet the required flow.
It is imperative that the condition of cooling water and closed
loop fluids be analyzed and maintained regularly and as
necessary to prevent corrosion of heat exchanger surfaces.
The oxygen content of river water and some other cooling
water sources will oxidize steel tubes and cause premature
failure. Careful attention to water treatment is essential to
ensure adequate life of steel cooler tubes if cooling tower
water is used.The condition of heat exchanger tubes should
be checked semiannually to prevent hazard.
NOTE: The water regulating valve shipped with the unit
will be sized to the specific flow for the unit.
THERMOSYPHON OIL COOLING (OPTIONAL)
Thermosyphon oil cooling is an economical, effective method
for cooling oil on screw compressor units. Thermosyphon
cooling utilizes liquid refrigerant at condenser pressure and
temperature which is partially vaporized at the condenser
temperature in a shell and tube- or plate-type vessel cool-
ing the oil to within 15°F of that temperature. The vapor, at
condensing pressure, is vented to the condenser inlet and
reliquified. This method is the most cost effective of all cur-
rently applied cooling systems since no compressor capacity
is lost or compressor power penalties incurred. The vapor
from the cooler need only be condensed, not compressed.
Refrigerant flow to the cooler is automatic, driven by the
thermosyphon principle, and cooling flow increases as the
oil inlet temperature rises.
EQUIPMENT - The basic equipment required for a ther-
mosyphon system consists of:
1. A source of liquid refrigerant at condensing pressure and
temperature located in close proximity to the unit to minimize
piping pressure drop.The liquid level in the refrigerant source
must be 6 to 8 feet above the center of the oil cooler.
2. A shell and tube- or plate-type oil cooler with a 300 psi
minimum design working pressure on both the oil and re-
frigerant sides.
Due to the many variations in refrigeration system design
and physical layout, several systems for ensuring the above
criteria are possible.
SYSTEM OPERATION - Liquid refrigerant fills the cooler tube
side up to the Thermosyphon receiver liquid level.
Water or hot oil (above the liquid temperature) flowing through
the cooler will cause some of the refrigerant to boil and
vaporize in the tubes. The vapor rises in the return line. The
density of the refrigerant liquid/vapor mixture in the return
line is considerably less than the density of the liquid in the
supply line. This imbalance provides a differential pressure
that sustains a flow condition to the oil cooler. This relation-
ship involves:
1. Liquid height above the cooler.
2. Oil heat of rejection.
3. Cooler size and piping pressure drops.