Frick RXB PLUS Owner's manual

Installation - Operation - Maintenance
ROTARY SCREW COMPRESSOR UNITS
WITH
MICROPROCESSOR CONTROL
ALL REFRIGERANTS
THIS MANUAL CONTAINS RIGGING, ASSEMBLY, START-UP, AND
MAINTENANCE INSTRUCTIONS. READ THOROUGHLY BEFORE
BEGINNING INSTALLATION. FAILURE TO FOLLOW THESE IN-
STRUCTIONS COULD RESULT IN DAMAGE OR IMPROPER OPERA-
TION OF THE UNIT.
S70-101 IOM/JAN 2000
File: SERVICE MANUAL - Section 70
Replaces: S70-101 IOM/APR 96
Dist: 3, 3a, 3b, 3c

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 IOM
Page 2 INSTALLATION - OPERATION - MAINTENANCE
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
Prestart Checklist............................................................34
TABLE OF CONTENTS
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 ...............................................................61
SPARE PARTS LIST.......................................................64
OPERATING LOG ..........................................................65

RXB PLUS ROTARY SCREW COMPRESSOR UNITS 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 autho-
rized Frick representative should be consulted for his ex-
pert guidance in this determination.
Proper performance and continued satisfaction with these
units is dependent upon:
CORRECT INSTALLATION
PROPER OPERATION
REGULAR, SYSTEMATIC MAINTENANCE
To ensure correctinstallationandapplication, 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
practicesandlocal codes,such asthoseoutlined inASHRAE
literature.
A refrigeration compressor is aVAPOR 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; operat-
ing cycles and defrosting periods are reasonable; and that
high side condensers are sized within system and compres-
sor design limits.
It is recommended that the entering vapor temperature to
the compressor be superheated to 10OF above the refriger-
ant 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 ex-
posed 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 execut-
ed.
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.Theunit
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
FRICKSALES ORDER NUMBERS fromthesedata plates.
COMPRESSOR DATA PLATE
UNIT DATA PLATE
GENERAL INFORMATION

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 IOM
Page 4
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 rela-
tively high frequency vibrations.
Firmlyanchoringthe compressor packageto asuitablefoun-
dation by proper application of grout and elimination of pip-
ing stress imposed on the compressor is the best insurance
for a trouble free installation. Use only the certified general
arrangement drawings from Frick to determine the mount-
ing foot locations and to allow for recommended clearances
around the unit for ease of operation and servicing. Foun-
dations 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 con-
creteandhousekeepingpads arerecommended. Anchorbolts
are required to firmly tie the unit to the floor. Once the unit is
rigged intoplace(SeeHANDLINGand MOVING),thefeetmust
then be shimmed in order to level the unit. The shims should
beplacedtopositionthefeetroughlyone inch abovethehouse-
keeping pad to allow room for grouting. An expansion-type
epoxy grout must be worked under all areas of the base with
novoidsandbe allowedto settlewith aslight outwardslope so
oil and water can run off of the base.
Wheninstallingona steel base, thefollowingguidelinesshould
beimplemented to properly design thesystem base:
1. UseI-beams inthe skidwhere thescrewcompressor 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 compressorunit feetshould be continuously weldedto
the system base at all points of contact, or bolted.
3. The compressor unit should not be mounted on vibration
isolatorsin order to holddown packagevibration levels.
4.The customer’s foundation for the system base should fully
support the system base under all areas, but most certainly
underthe I-beams thatsupportthecompressor package.
When installing on the upper floors of buildings, extra pre-
cautions should be taken to prevent normal package vibra-
tion from being transferred to the building structure. It may
be necessary to use rubber or spring isolators, or a combi-
nation of both, to prevent the transmission of compressor
vibrationdirectlyto thestructure. However,this mayincrease
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. Rub-
ber or spring pipe supports may be required to avoid excit-
ing the building structure at any pipe supports close to the
compressor package. It is best to employ a vibration expert
in the design of a proper mounting arrangement.
Inanyscrewcompressor installation, suctionanddischarge 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.
A licensed architect should be consulted to determine the
proper foundation requirements for any large engine or tur-
bine drive.
INSTALLATION
NOZ.
SIZE
NPS
(in.)
AXIAL VERT. AXIAL VERT. LAT.LAT.
MRMCMLPV
CVL
1
1.25
1.5
2
3
4
5
6
8
10
12
14
50
50
75
125
250
400
450
650
900
1200
1500
2000
50
50
75
125
250
400
450
650
900
1200
1500
2000
50
50
100
150
225
300
400
650
1500
1500
1500
1700
25
25
40
70
175
200
400
750
1000
1200
1500
1800
25
25
40
70
175
200
400
750
1000
1200
1500
1800
25
25
50
100
250
400
425
1000
1500
1500
1500
2000
ALLOWABLE FLANGE LOADS
MOMENTS (ft-lbf) LOAD (lbf)
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
compressorside of theunit because60 percentof the weight
is toward the compressor end. If a motor is mounted, ap-
propriate 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 pack-
age, such as an external oil cooler, etc., as the center of
balance will be affected.
FIG. 1 - RECOMMENDED LIFTING METHOD
When applying screw compressors at high pressures, the
customer must be prepared for package vibration and noise
higherthan the valuespredictedfornormal refrigerationduty.
Proper foundations and proper installation methods are vi-
tal;and even then, sound attenuation or noise curtains may
be required to reduce noise to desired levels.
For more detailed information on Screw Compressor Foun-
dations, please request Frick publication S70-210 IB.

RXB PLUS ROTARY SCREW COMPRESSOR UNITS S70-101 IOM
Page 5
INSTALLATION
MAXIMUM
TOTAL
INDICATOR
READING
CLAMP
BOLT
TORQUE
KEYWAY
SETSCREW
TORQUE
BETWEEN SHAFT SPACING SHAFT ENGAGEMENT FACE SPACING
CH
COUP-
LING
SIZE in. mm mm mmin. in. mm in. in. mm in. mm ft-lb Nm ft-lb Nm
COUPLING HUB
MIN * MAX MIN MAX
CH COUPLING DATA TABLE
76.2
76.2
96.8
90.5
101.6
138.1
161.9
149.2
23.8
34.9
46.0
60.3
19.0
25.4
25.4
31.8
22.2
27.0
28.6
36.5
3
3
3-13/16
3-9/16
3/4
1
1
1-1/4
15/16
1-3/8
1-13/16
2-3/8
7/8
1-1/16
1-1/8
1-7/16
.004
.004
.004
.004
.104
.104
.104
.104
10
20
35
35
13.6
27.1
47.5
47.5
13
13
13
13
17.6
17.6
17.6
17.6
3-1/4
3-7/16
4
5-7/16
6
7
8
9C
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 push-
ing against the skid. NEVER MOVE THE UNIT BY PUSH-
ING OR FORKING AGAINST THE SEPARATOR SHELL
OR ITS MOUNTING SUPPORTS.
SKID REMOVAL
If the unit is rigged into place the skid can be removed by
takingoff thenutsandbolts thatare fasteningtheunit mount-
ing 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.
Spreadthe skid to clear the unit mountingsupport, 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 – TheT.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.
Makesure that thekeys onthe compressorand 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 LUBRI-
CANT ON THESE BOLTS.
4. Proceed to Coupling Alignment.
DRIVE COUPLING
FIG. 3 - COUPLING/SHAFT KEYS INSTALLATION

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 IOM
Page 6 INSTALLATION
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 fac-
tory but realignment MUST ALWAYS be done on the job
site after the unit is securely mounted on its foundation. Ini-
tial 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 tempera-
ture. 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.
Usedial 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. Setthe dialindicator atzero when viewed at the12 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.
Afteradjustments havebeen madefor angular misalignment
retighten anchor bolts to prevent inaccurate readings. Re-
peat Steps 3 through 5 to check corrections. Further adjust-
ments and checks shall be made for angular misalignment
until the total indicator reading is within the specified toler-
ance.
FIG. 2 - DIAL INDICATOR ATTACHED (AT 12 O'CLOCK)
FIG. 3 - DIAL INDICATOR AT 6 O'CLOCK

RXB PLUS ROTARY SCREW COMPRESSOR UNITS S70-101 IOM
Page 7
PARALLEL ALIGNMENT
6. To check parallel alignment, as shown in Fig. 4, reposi-
tion 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.Loosenmotor anchor boltsand add orremoveshims under
thefour motor feet until parallelheight misalignment is within
specified tolerance when anchor bolts are retightened.
CARE MUST BE USED WHEN
CORRECTING FOR PARALLEL
MISALIGNMENT TO ENSURE
THATTHE AXIAL SPACING AND ANGULAR MISALIGN-
MENT IS NOT SIGNIFICANTLY DISTURBED.
9. After the parallel height misalignment is within tolerance,
repeatSteps 1through 5 until angular misalignmentis 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 adjust-
ing screws until reading is within specified tolerance.
11. Recheck angular misalignment and realign if necessary.
12.Tightenmotor anchorbolts androtate bothcoupling hubs
together, checking the angular and parallel misalignment
through the full 360Otravel at 90Oincrements. If dial read-
ingsare inexcess of specifiedtolerance, realignas 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 rota-
tion. COMPRESSOR ROTATION IS CLOCKWISE WHEN
FACING COMPRESSOR SHAFT (see "CHECKING MO-
TOR/COMPRESSOR ROTATION", page 8). After verifica-
tion, 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 lim-
its 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
INSTALLATION

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 IOM
Page 8 INSTALLATION
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 cou-
pling motor hub, then take readings of both the face and rim
of the compressor hub. If these readings are within toler-
ance,record reading,attach couplingguard, and restart unit.
However, if the reading is not within limits, compare the hot
reading with the cold alignment and adjust for this differ-
ence; i.e. if the rim at 0Oand 180Oreadings 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 re-
check 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-
INGTHE END OFTHE 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
corrosiondamage. Reasonable consideration mustbe given
to proper care for the solid state components of the micro-
processor. Unit which will be stored for more than two
months must have the nitrogen charge checked peri-
odically.
COMPRESSOR
COMPRESSOR UNIT OIL
DO NOT MIX OILS of different
brands, manufacturers, or types.
Mixing of oils may cause excessive
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 en-
gineering 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 lubri-
cant 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 lev-
els.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 liq-
uid carryover or malfunction of the oil return.
OIL HEATER
Standard units are equipped with a 500 watt oil heater, pro-
vidingsufficient heatto maintain theoil temperatureformost
indoor applications during shutdown cycles to permit safe

RXB PLUS ROTARY SCREW COMPRESSOR UNITS S70-101 IOM
Page 9
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
valvebulbinto the thermowellprovided inthe separator.High
pressure gas is connected through the regulator to the ex-
ternal port on the liquid injection valve to control oil tem-
perature. 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 (lowVi) or dual-port (lowVi and highVi), liquid injection
oil cooling.Single port will be furnished for low compression
ratio operation and dual port for high compression ratio op-
eration. Booster compressor units use single-port, liquid in-
jection oil cooling due to the typically lower compression
ratios.
The control system on high-stage units with dual-port, liq-
uid
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.
Thefollowingtablegivesthecondensing temperature(s)with
the corresponding maximum evaporator temperature limit
for liquid injection usage and the minimum evaporator tem-
perature for a single-port application.
TABLE - EVAPORATORTEMPERATURE 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
75OF +10OF+5
OF -23OF
85OF +25OF +15OF -17OF
95OF +35OF +25OF -11OF
105OF +40OF +35OF-4
OF
* Dual Injection Kit will be shipped by Frick
below these temperatures.
INSTALLATION
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.
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 min-
utes of liquid injection oil cooling.
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
WILLBURN OUT.THE OIL HEATERWILLBE 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.
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 IM-
PORTANCE 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.

RXB PLUS ROTARY SCREW COMPRESSOR UNITSS70-101 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 (quan-
tity 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)thewater regulatorbe installedonthe wateroutlet
connection. Insert the water regulator valve bulb and well in
the chamber provided on the oil outlet connection. Deter-
mine 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.
Itis imperative thatthe condition ofcooling water andclosed
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)
Thermosyphonoil coolingis an economical,effectivemethod
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 15OF 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 capac-
ity is lost or compressor power penalties incurred.The va-
por from the cooler need only be condensed, not com-
pressed. 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 mini-
mize 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 re-
turn line is considerably less than the density of the liquid in
the supply line.This imbalance provides a differential pres-
sure that sustains a flow condition to the oil cooler.This re-
lationship involves:
1. Liquid height above the cooler.
2. Oil heat of rejection.
3. Cooler size and piping pressure drops.
INSTALLATION