Frick RWB II Owner's manual

Installation - Operation - Maintenance
ROTARY SCREW COMPRESSOR UNITS
ALL REFRIGERANTS
MODELS
60 through 480
THIS MANUAL CONTAINS RIGGING, ASSEMBLY, START-UP, AND
MAINTENANCEINSTRUCTIONS. READTHOROUGHLYBEFOREBE-
GINNING INSTALLATION. FAILURETO FOLLOWTHESE INSTRUC-
TIONS COULD RESULT IN DAMAGE OR IMPROPER OPERATION
OFTHE UNIT.
S70-200 IOM/OCT 2004
File: SERVICE MANUAL - Section 70
Replaces: S70-200 IOM/AUG 2001
Dist: 3, 3a, 3b, 3c

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION - OPERATION - MAINTENANCE
S70-200 IOM
Page 2
Contents
Maintenance
GENERAL INFORMATION..............................................25
NORMAL MAINTENANCE OPERATIONS......................25
GENERAL MAINTENANCE............................................25
COMPRESSOR SHUTDOWN and START-UP................25
GENERAL INSTRUCTIONS FOR REPLACING
COMPRESSOR UNIT COMPONENTS.....................26
OIL FILTER (OF-1) MAIN SINGLE/DUAL .......................26
STRAINER - DEMAND OIL PUMP .................................26
STRAINER - LIQUID INJECTION...................................27
COALESCER FILTER ELEMENT(S)...............................27
CHANGING OIL ..............................................................27
DEMAND PUMP DISASSEMBLY....................................28
TROUBLESHOOTING THE DEMAND PUMP.................30
RECOMMENDED MAINTENANCE PROGRAM.............32
VIBRATION ANALYSIS ...................................................32
MOTOR BEARINGS........................................................32
OIL QUALITY and ANALYSIS .........................................32
OPERATING LOG...........................................................33
MAINTENANCE SCHEDULE..........................................33
TROUBLESHOOTING GUIDE........................................34
ABNORMAL OPERATION
ANALYSIS and CORRECTION................................34
SERVICING THE COLD-START VALVE..........................34
PRESSURE TRANSDUCERS - TESTING......................34
PRESSURE TRANSDUCERS - REPLACEMENT ..........35
SV POSITION POTENTIOMETER
REPLACEMENT AND ADJUSTMENT.....................36
VOLUMIZER®POTENTIOMETER
REPLACEMENT AND ADJUSTMENT.....................36
TEMPERATURE and/or PRESSURE ADJUSTMENT.....37
OIL LEVEL TRANSMITTER REPLACEMENT................37
TROUBLESHOOTING
RWB II COMPRESSOR...........................................37
OIL SEPARATION SYSTEM ....................................38
HYDRAULIC SYSTEM.............................................38
LIQUID INJECTION OIL COOLING SYSTEM.........39
DEMAND PUMP SYSTEM.......................................39
THERMAL EXPANSION VALVES....................................40
JORDANTEMPERATURE REGULATOR VALVE.............41
BARE COMPRESSOR MOUNTING...............................42
SHUTDOWN DUE TO IMPROPER OIL PRESSURE ....42
GREASE COMPATIBILITY..............................................42
NLGI Grease Compatibility Chart....................................42
P & I DIAGRAMS............................................................43
PROPER INSTALLATION OF ELECTRONIC EQUIP-
MENT IN AN INDUSTRIAL ENVIRONMENT..........47
FORMS
OPERATING LOG SHEET.......................................50
COMPRESSOR PRESTART CHECKLIST ..............51
START-UP REPORT ................................................52
VIBRATION DATA SHEET........................................54
RECOMMENDED SPARE PARTS..................................55
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
Indicates a potentially hazardous situation or practice which, if not avoided, will result in death
or serious injury.
SAFETY PRECAUTION DEFINITIONS
Indicates a potentially hazardous situation or practice which, if not avoided, will result in dam-
age to equipment and/or minor injury.
NOTE: Indicates an operating procedure, practice, etc., or portion thereof which is essential to highlight.
PREFACE..........................................................................3
DESIGN LIMITATIONS......................................................3
JOB INSPECTION.............................................................3
TRANSIT DAMAGE CLAIMS ............................................3
COMPRESSOR and UNIT IDENTIFICATION...................3
Installation
FOUNDATION ...................................................................4
RIGGING and HANDLING ................................................4
SKID REMOVAL................................................................4
MOTOR MOUNTING.........................................................5
CHECKING MOTOR/COMPRESSOR ROTATION..............5
COMPRESSOR/MOTOR COUPLINGS INSTALLATION...5
COUPLING ALIGNMENT PROCEDURE..........................7
HOT ALIGNMENT OF COMPRESSOR/MOTOR................9
OIL PUMP COUPLING......................................................9
HOLDING CHARGE AND STORAGE...............................9
COMPRESSOR UNIT OIL ................................................9
OIL CHARGE ....................................................................9
OIL HEATER(S).................................................................9
OIL FILTER(S).................................................................10
THERMOSYPHON OIL COOLING..................................10
LIQUID INJECTION OIL COOLING (OPTIONAL)...........11
LIQUID LINE SIZES/RECEIVER VOLUME.....................12
WATER-COOLED OIL COOLING (Optional)...................12
ECONOMIZER - HIGH STAGE (OPTIONAL)..................12
ELECTRICAL ..................................................................14
MOTOR STARTER PACKAGE ........................................14
MINIMUM BURDEN RATINGS........................................15
CONTROL POWER REGULATOR..................................16
Operation
OPERATION and START-UP INSTRUCTIONS...............17
TDSH COMPRESSOR....................................................17
COMPRESSOR LUBRICATION SYSTEM......................17
NO PUMP OIL SYSTEM.................................................17
COLD-START SYSTEM ..................................................17
DEMAND PUMP OIL SYSTEM.......................................18
COMPRESSOR OIL SEPARATION SYSTEM.................18
COMPRESSOR HYDRAULIC SYSTEM.........................19
VOLUMIZER®VOLUME RATIO CONTROL....................19
COMPRESSOR OIL COOLING SYSTEMS....................20
SINGLE-PORT LIQUID INJECTION ...............................20
RWB II BOOSTER OR SWING DUTY APPLICATION....20
DUAL-PORT LIQUID INJECTION...................................20
LIQUID INJECTION ADJUSTMENT PROCEDURE .......20
QUANTUM™ EZ-COOL™LIQUID INJECTION
ADJUSTMENT PROCEDURE.................................21
SUCTION CHECK VALVE...............................................22
SUCTION CHECK VALVE BYPASS................................23
LOW AMBIENT OPERATION..........................................23
SUCTION CHECK VALVEPOWER ASSIST KIT.............23
INITIAL START-UP ..........................................................24
INITIAL START-UP PROCEDURE ..................................24
NORMAL START-UP PROCEDURE...............................24

RWB II ROTARY SCREW COMPRESSOR UNITS
GENERAL INFORMATION S70-200 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
RWB II Rotary Screw Compressor Units.
For information about the functions of the electrical control
panel,communications,specifications, andwiringdiagrams,
see S90-010 O, M, and CS (Quantum™panel) or S70-200
OM (Plus panel).
Itismost importantthat these unitsbe properly appliedtoan
adequately controlled refrigeration system.Your authorized
Frickrepresentativeshould beconsultedforexpert guidance
in this determination.
Proper performance and continued satisfaction with these
units is dependent upon:
CORRECT INSTALLATION
PROPER OPERATION
REGULAR, SYSTEMATIC MAINTENANCE
To ensure correctinstallation andapplication,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
practicesand localcodes,such asthose outlinedin ASHRAE
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
surgesareknownand provisionsmade for control;operating
cycles and defrosting periods are reasonable;and that high
side condensers are sized within system and compressor
design limits.
Itisrecommendedthatthe enteringvaportemperature tothe
compressor be superheated to 10°F above the refrigerant
saturation temperature. This assures 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.
E70-200 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

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 4
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
FOUNDATION
Each RWB II Rotary Screw Compressor Unit is shipped
mounted on a wood skid which must be removed prior to unit
installation.
Allow space for servicing both ends
of the unit. A minimum of 36 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
andamass isrequired to effectivelydampen theserelatively
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 Co. to determine
the mounting foot locations and to allow for recommended
clearances around the unit for ease of operation and servic-
ing. 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 con-
crete 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 RIGGING and HANDLING),
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.
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.
Wheninstalling onthe upperfloorsofbuildings,extraprecau-
tions should be taken to prevent normal package vibration
from being transferred to the building structure. It may be
necessaryto userubberor springisolators, ora combination
of both, to prevent the transmission of compressor vibration
directlyto thestructure. However,thismayincreasepackage
vibrationlevelsbecause thecompressorisnotincontactwith
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 atany pipesupports closeto thecompressorpack-
age. It is best to employ a vibration expert in the design of
a proper mounting arrangement.
Inanyscrewcompressorinstallation,suction anddischargelines
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
turbine drive.
When applying screw compressors at high pressures, the
customer must be prepared for package vibration and noise
higher thanthe values predictedfornormal refrigeration duty.
Properfoundationsand properinstallation methodsarevital;
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.
RIGGING and HANDLING
THIS SCREW COMPRESSOR
PACKAGE MAY BE TOP-HEAVY.
USE CAUTION IN RIGGING AND
HANDLING.
The unit can be moved with rigging, using a crane or forklift,
by hooking into the four lifting eyes on the compressor and
motor bases. If no motor is mounted, the lifting ring should
be moved to the compressor side of the center of the unit
because 60 percent of the weight is toward the compressor
end.If a motor is mounted appropriate adjustment in the lift-
ing 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 effected.
Theunit canbe movedwithaforkliftbyforkingundertheskid,
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 a5 tonjackunder theseparatorraisetheunitat the
compressorenduntil itclears thetwomountingbolts. Spread
theskidto clearthe unitmountingsupport, thenlowertheunit
to the surface. Repeat procedure on opposite end.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 5
226 313/16 96.8 1/64 .40 .003 .076 14 19.5
5/16 - 24 UNRF
263 45/16 109.5 1/32 .79 .004 .102 22 30.6
3/8- 24 UNRF
301 47/8123.8 1/32 .79 .004 .102 37 51.5
7/16 - 20 UNRF
351 57/8149.2 1/32 .79 .004 .102 55 76.5
1/2- 20 UNRF
401 611/16 169.9 1/32 .79 .004 .102 49 68.2
1/2- 20 UNRF
8 313/16 96.8 4 101.6 11/16 27.0 113/16 46.0 11/828.6 .004 .104 55 74.6
3/8- 24 UNF 13 17.6
9 45/16 109.5 57/16 138.1 17/16 36.5 23/16 61.9 17/16 36.5 .004 .104 55 74.6
3/8- 24 UNF 13 17.6
10 45/16 109.5 63/8161.9 111/16 42.9 29/16 65.1 111/16 42.9 .004 .104 130 176.4
1/2- 20 UNF 13 17.6
11 47/8123.8 57/8149.2 2 50.8 27/873.0 17/847.6 .004 .104 130 176.4
1/2- 20 UNF 13 17.6
DBZ-B HUB FACE MAXIMUMTOTAL CLAMP BOLT
COUPLING SPACING +/- INDICATOR READING TORQUE (LUBE) SIZE
SIZE in. mm in. mm in. mm ft-lb Nm
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 to see that the
shaftsareproperly spacedforthe couplingbeing used. Re-
fer to the coupling data tables for the applicable dimension
(pages 5 and 6).
CHECKING MOTOR/COMPRESSOR ROTATION
Make sure coupling hubs are tight-
ened to theshaft before rotating the
motor to prevent them from flying
off and possibly causing serious injury or death.
COMPRESSOR ROTATION IS
CLOCKWISE WHEN FACING
THEENDOFTHECOMPRESSOR
SHAFT. Under NO conditions
should the motor rotation be
checked with the coupling center
installed as damage to the com-
pressormayresult. Bump themo-
torto checkforcorrect compressor
rotation. After verifi cation, install
gear or disk drive spacer, as applicable.
COMPRESSOR/MOTOR COUPLINGS
INSTALLATION
RWB II 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.
CH COUPLING DATATABLE
3. Check that the keys fit the hubs and shafts properly.
CH COUPLING – TheT.B.Woods Elastomeric CH Coupling
is used in most applications up to 600 HP. 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 gearwhich floatsfreely betweenthe hubs.Install
as follows:
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 on the shafts.
2. Holdthe elastomeric gearbetweenthehubsandslideboth
hubs onto the gear to fully engage the mating teeth.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
givenintheCH DataTable.DO NOT USE ANY LUBRICANT
ONTHESE BOLTS.
4. Proceed to Coupling Alignment.
DBZ-B COUPLING – The Thomas DBZ-B coupling is used
on applications above 600 HP and with sleeve bearing mo-
tors that do not have axial end float constraint.The DBZ-B
coupling consists of two drive hubs and a flexible metal disc
drive spacer that is bolted to both hubs.A flexible steel disc
pack serves as the drive element.This disc pack is bolted to
the coupling hubs and prevents axial end float between the
compressor and motor shafts which may occur with sleeve
bearing motors. On sleeve bearing motors, the magnetic
center must be determined and maintained by securing the
coupling to the motor shaft with the shaft properly located.
Injury may occur if loose clothing,
etc. becomes entangled on the
spinning motor shaft.
If the motor is coupled to the compressor using a fixed-end-
playcoupling,suchasaDBZ-Bcoupling,and themotor isnot
properly centered, additional thrust loads will be transmitted
to the compressor bearings that could result in premature
bearing failure. Install as follows:
1. Remove the eight locknuts and long bolts attaching the
center member to the disc pack.
2. Slide the disc pack and coupling hub assemblies on their
respective shafts.
DBZ-B COUPLING DATATABLE
* Required for shaft seal removal.
CH COUPLING HUB MAXTOTAL KEYWAY
COUP- BETWEEN SHAFT SPACING SHAFT ENGAGEMENT FACE INDICATOR CLAMP BOLT SETSCREW
LING MIN* MAX MIN MAX SPACING READING TORQUE (DRY) TORQUE
SIZE in. mm in. mm in. mm in. mm in. mm in. mm ft-lb Nm SIZE ft-lb Nm

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 6
225 5 127.0 1/32 .914 .004 .102 .004 .102 7.5 10.5
1/4-20 UNRF
262 5 127.0 1/32 .914 .004 .102 .004 .102 22 30.6
3/8-24 UNRF
312 5-1/2 139.7 3/64 1.295 .004 .102 .004 .102 37 51.5
7/16-20 UNRF
350 6 152.4 3/64 1.295 .004 .102 .004 .102 55 76.5
1/2-20 UNRF
375 7 177.8 1/16 1.574 .004 .102 .004 .102 55 76.5
1/2-20 UNRF
425 7 177.8 1/16 1.574 .004 .102 .004 .102 96 133.6
5/8-18 UNRF
450 8 203.2 1/16 1.574 .004 .102 .004 .102 96 133.6
5/8-18 UNRF
500 9 228.6 5/64 2.083 .004 .102 .004 .102 250 348.0
7/8-14 UNRF
BP HUB FACE * DISC PACK CLAMP BOLT
SERIES SPACING BOLT TORQ. TORQ. DRY SIZE
SIZE in. mm ft-lb Nm ft-lb Nm UNF
BP48 4.88 124 40 54 41 56 3/8-24
BP53 5.88 150 60 81 65 88
7/16-20
BP58 6.00 152 120 163 100 136 1/2-20
BP58 6.69 170 120 163 100 136 1/2-20
BP63 7.00 179 120 163 100 136 1/2-20
* Max total indicator reading .003 in. or .076 mm for all sizes.
All rotating power transmission equipment is potentially dangerous. Ensure that the couplings are
properly guarded prior to turning on the power. Coupling guards are provided with the equipment
and must be in place and secured properly while the equipment is in operation.
SERIES 52 COUPLING DATATABLE
3. Adjust the distance between hub faces as specified in the
DBZ-B DataTable by sliding the hubs.Key and secure hubs
to the shafts by tightening setscrews.
4. Reinstall the eight previously removed bolts and locknuts.
Alternately tighten eachlocknutas youwouldthelug nutson
an automobile. NOTE: ALWAYS TURN THE NUT. NEVER
TURNTHE BOLT.
5.Torque the locknuts to the value shown in the DBZ-B Data
Table for the size coupling being installed.
Lubricated and/or plated bolts and
locknuts develop higher bolt ten-
sion with less tightening than those
that are dry and not plated. Torques for lubricated and/or
platedboltsand locknutswillgenerallyfall in thelowerrange;
while those that are dry or as received from the factory fall
into the upper range.Torque readings should be observed
while locknut is being turned.
6. Proceed to coupling alignment.
SERIES 52 COUPLING – TheThomas Series 52 couplingis
alsoused onapplicationsabove600HP.Ithastwodrivehubs,
acenterspool, anddiscpackswhich are boltedbetween the
centerspooland eachdrivehub.A centerspooland twoflex-
ible steel disc packs serve as the drive element.These three
parts, situated between the motor and compressor hubs,
prevent axial end float between the motor and compressor
shafts.End float tends to occur with sleeve bearing motors.
The magnetic center of the sleeve bearing motors must be
determined and maintained by securing the coupling hub to
the motor shaft with the shaft properly located.
Injury may occur if loose clothing,
etc. becomes entangled on the
spinning motor shaft.
If the motor is coupled to the compressor using a fixed-end-
play coupling such as the Series 52 coupling and the motor
is not properly centered, the additional thrust loads will be
transmittedto thecompressor bearings.Thisadditional thrust
could result in premature bearing failure. Install as follows:
1. Before proceeding with the alignment process found
on pages 7 and 8 of this manual, disassemble the Series
52 coupling noting the arrangement of bolts, washers,
and nuts as THEY MUST BE REPLACED IN THE SAME
ORDER. Mark the adjoining bolt holes of each part, the two
hubs, the two disc packs, and the center spool, so they are
put back together in the same position.
2. Mount the coupling hubs on their respective shafts. The
hub is bored for an interference fit on the shaft. Heating of
the coupling hub may be necessary for assembly. DO NOT
SPOT HEAT THE HUB as it may cause distortion. Heat in
water, oil, or use a SOFT open flame and quickly position
on the shaft.
3. Adjust the distance between hub faces, as specified in the
Series 52 Coupling Data Table, by sliding the hubs. Key and
secure the hubs to the shafts by tightening the set screws.
4. Reassemble the coupling with the disc packs and the
center spool. Ensure that they are reassembled exactly as
they were disassembled.
WOODS BP SERIES COUPLING – is also used on appli-
cations above 600 HP.It utilizes a center spool and two flex-
iblesteel discpacksasthe driveelement.Thesethreeparts,
situated between the motor and compressor hubs, prevent
axial end float between the motor and compressor shafts.
End float tends to occur with sleeve bearing motors.
Injury may occur if loose clothing,
etc. becomes entangled on the
spinning motor shaft.
If the motor is coupled to the compressor using a fixed-end-
play coupling and the motor is not properly centered, the
additional thrust loads will be transmitted to the compressor
bearings. This additional thrust could result in premature
bearing failure. Install the BP Series coupling using the fol-
lowing instructions:
1. Before proceeding with the alignment process in the fol-
lowing section, disassemble the BP Series coupling noting
the arrangement of bolts, washers, and nuts as THEY
MUST BE REPLACED IN THE SAME ORDER. Mark the
adjoining bolt holes of each part, the two hubs, the two disc
packs, and the center spool, so they are put back together
in the same position.
2. Install the motor and compressor coupling hubs on their
respective shafts with the keys. Ensure that the hubs slide,
so that when the shim packs are installed, no axial stresses
are transferred to the shim packs because the coupling hub
is stuck.
BP SERIES COUPLING DATATABLE
COUP- HUB FACE MAXTOTAL INDICATOR READING CLAMP BOLT
LING SPACING +/- ANGULAR PARALLEL TORQUE (LUBE) SIZE
SIZE in. mm in. mm in. mm in. mm ft-lb Nm

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 7
Figure 1 - Angular Misalignment
Figure 2 - Dial Indicator Attached (at 12 o'clock)
Figure 3 - Dial Indicator at 6 o'clock
3. Reassemblethe couplingwith thediscpacksandthe cen-
terspool.Centerthecoupling betweentheshaftsand ensure
that the keys are fully engaged in their keyways.Ensure that
they are reassembled exactly as they were disassembled.
Torque disc pack hardware to specifi cation in BP Series
Coupling Data Table.
4. Key and secure the hubs to the shafts by tightening the
clamping bolts.Make sure that the keyways are offset 180°
to maintain balance.
5.Torque theclampingbolts ofboth hubs tothe torque value
given in the Data Table. DO NOT USE ANY LUBRICANT
ONTHESE BOLTS.
6. IMPORTANT: Only after the shaft clamping bolts are
tightened to their final torque can the keyway setscrew be
tightened!If thekeywaysetscrewistightenedbeforetheshaft
clamping bolts are tightened, then the hub can be cocked
on the shaft.
7. Proceed to Coupling Alignment.
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.
The following procedure is applicable to both the CH and
DBZ-B couplings. Dial indicators are to be used to measu-
re the angular and parallel shaft misalignment. Coupling
alignment is attained by alternately measuring angular and
parallel misalignment and repositioning the motor until the
misalignment is within specified tolerances.
ALWAYS LOCK OUT MAIN MOTOR
DISCONNECT BEFORETOUCHING
MOTOR SHAFT. MISALIGNMENT
MUST NOT EXCEED .004" FOR ALL CH, DBZ-B AND
SERIES 52 COUPLINGS EXCEPT DBZ-B 226 WHICH
SHALL NOT EXCEED .003".
ANGULAR ALIGNMENT
1.To check angular alignment, as shown in Figure 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 Figure 2.
NOTE: When DBZ-B couplings are used on motors
with sleeve bearings, it is necessary to secure the two
coupling hubs with a bolt to prevent them from drifting
apart when rotating.
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. Setthedial indicatorat zerowhen viewed atthe 12o’clock
position, as shown in Figure 2.
4. Rotate both coupling hubs together 180° (6 o’clock po-
sition),asshownin Figure3.At thisposition thedialindicator
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.
Afteradjustmentshavebeenmade forangularmisalignment
retightenanchor boltsto preventinaccuratereadings.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.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 8
PARALLEL ALIGNMENT
6. To check parallel alignment, as shown in Figure 4, repo-
sition dial indicator so the stem is in contact with the rim of
the compressor hub, as shown in Figure 5.
Check the dial indicator to be sure that the indicator stem is
slightly loaded so as to allow movement in both directions.
7.Checkparallel heightmisalignment by settingdial indicator
at zero when viewed at the 12 o'clock position.Rotate both
couplinghubstogether 180°(6o'clockposition).At this posi-
tionthedial indicatorwillshowTWICE theamount ofparallel
height misalignment.
8.Loosenmotoranchorboltsandaddorremoveshimsunder
thefourmotor feetuntil parallelheight misalignmentis 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,
repeatSteps1 through5 until angularmisalignment iswithin
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 Figure 6.
Set indicator at zero and rotate both coupling hubs together
180° (9 o'clock position), as shown in Figure 5.
Adjustparallel lateralmisalignment usingthe motoradjusting
screws until reading is within specified tolerance.
11. Recheck angular misalignment and realign if nec-
essary.
12.Tighten motoranchor boltsand rotatebothcouplinghubs
together, checking the angular and parallel misalignment
throughthefull 360° travel at90°increments.If dialreadings
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.
Install the coupling guard before
operating the compressor.
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.
Figure 4 - Parallel Misalignment
Figure 5 - Dial Indicator Attached (at 9 o'clock)
Figure 6 - Dial Indicator at 3 o'clock

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 9
HOT ALIGNMENT OF COMPRESSOR/MOTOR
Hotalignmentscan onlybe made afterthe unithasoperated
for several hours and all components are at operating tem-
peratures.
Shut down the unit and quickly affix dial indicator to coupling
motor hub, then take readings of both the face and rim of the
compressorhub.Ifthese readingsarewithintolerance,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.
Aftertheinitial hotalignment adjustmentis 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
BEFORE OPERATING COM-
PRESSOR.
OIL PUMP COUPLING
Compressor units with direct motor/pump coupled pumps
need no pump/motor coupling alignment since this is main-
tained by the close-coupled arrangement.
HOLDING CHARGE AND STORAGE
Each RWB II compressor unit is pressure and leak tested at
theFrickfactory andthenthoroughly evacuated andcharged
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.
Holding charge shipping gauges
onseparator andexternal oil cooler
are rated for 30 PSIG and are for
checking the shipping charge only. They must be re-
moved before pressure testing the system and before
charging the system with refrigerant. Failure to remove
these gauges may result in catastrophic failure of the
gauge and uncontrolled release of refrigerant resulting
in serious injury or death.
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.
Unitwhich willbestoredformore thantwo monthsmusthave
the nitrogen charge checked periodically.
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 only Frick®refrigeration oil
and filters or warranty claims 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 mid-
way in the top sight glass located
midway along the oil separator
shell.Normal operating level is
midway between the top sight
glass and bottom sight glass.
The table gives the approximate oil
charge quantity.
* Includes total in oil separator and
piping. Additional oil supplied for
oil cooler.
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 at the compressor end. Using a
pressure-type pump and the recommended Frick oil, open
the charging valve and pump oil into the separator. NOTE:
Fill slowly because oil will fill up in the separator faster
than it shows in the sight glass.
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 in the coalescing end
of the separator near the discharge connection should
remain empty.
OIL HEATER(S)
Standard units are equipped with two or three 500 watt oil
heaters, providing sufficient heat to maintain the oil tem-
peratureformost indoorapplications duringshutdowncycles
to permit safe start-up. Should additional heating capacity
be required because of low ambient temperature, contact
Frick. The heaters are energized only when the unit is not
in operation.
DO NOT ENERGIZETHE HEATERS
when there is no oil in the unit, the
heaters will burn out. The oil heat-
ers will be energized whenever 120 volt control power is
applied to the unit and the compressor is not running,
unless the 16 amp circuit breaker in the micro enclosure
is turned off.
60 35
76 35
100 65
134 65
177 110
222 110
270 140
316 140
399 140
480 170
BASIC*
CHARGE
(gal.)
RWB II
MODEL
NO.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 10
OIL FILTER(S)
Use of filter elements other than
Frick may cause warranty claim
may to be denied.
The oil filter(s) and coalescer filter element(s) shipped with
the unit are best suited to ensure proper filtration and op-
eration of the system.
THERMOSYPHON OIL COOLING
Thermosyphon oilcooling isan economical,effectivemethod
for cooling oil on screw compressor units. Thermosyphon
cooling utilizes liquid refrigerant at condenser pressure and
temperaturethat ispartially vaporizedat thecondenser tem-
perature in a plate and shell vessel, cooling the oil to within
15°Fof thattemperature.The vapor,at condensingpressure,
isventedto thecondenser inletand reliquified.Thismethod is
themost costeffectiveof allcurrently appliedcooling systems
since no compressor capacity is lost or compressor power
penalties incurred.The vapor from the cooler need only be
condensed,not compressed.Refrigerantflowto the cooleris
automatic,drivenbythethermosyphonprincipleand 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 minimum above the center of the
oil cooler.
2. A plate and shell oil cooler with:
Plate Side: Oil 400 psi design
Shell Side: Refrigerant 400 psi design
Due to the many variations in refrigeration system design
and physical layout, several systems for assuring the above
criteria are possible.
SYSTEM OPERATION - Liquid refrigerant fills the cooler
shell side up to theThermosyphon receiver liquid level.See
Figure 7.
Hot oil (above the liquid temperature) flowing through the
cooler will cause some of the refrigerant to boil and vaporize.
Thevapor risesinthe returnline.Thedensityof therefrigerant
liquid/vapormixture inthe returnline isconsiderablylessthan
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 relationship involves:
1. Liquid height above the cooler.
2. Oil heat of rejection.
3. Cooler size and piping pressure drops.
Current thermosyphon systems are using two-pass oil cool-
ers and flow rates based on 3:1 overfeed.
The liquid/vapor returned from the cooler is separated in the
receiver.Thevapor is ventedto the condenserinlet and need
only be reliquified since it is still at condenser pressure.
OILTEMPERATURE CONTROL - Oil temperature will gen-
erally run about 15 - 35°F above condensing temperature.
In many cases, an oil temperature control is not required if
condensing temperature is above 65°F as oil temperature
can be allowed to float with condenser temperature.
Condensing Temperature: 65°F - 105°F
Oil Temperature: 80°F - 140°F
INSTALLATION -The plate and shell type thermosyphon oil
cooler with oil-side piping and a thermostatically controlled
mixingvalve(if ordered)are factory mountedand piped.The
customer must supply and install all piping and equipment
located outside of the shaded area on the piping diagram
with consideration given to the following:
1.The refrigerant source, thermosyphon or system receiver,
should be in close proximity to the unit to minimize piping
pressure drop.
2. The liquid level in the refrigerant source must be 6to 8
feet minimum above the center of the oil cooler.
3. A safety valve should be installed if refrigerant isolation
valves are used for the oil cooler.
Thecomponent andpipingarrangementshownin Figure8, is
intendedonlyto illustratetheoperating principles ofthermo-
syphon oil cooling. Other component layouts may be better
suitedto aspecific installation.RefertopublicationE70-900E
for additional information on Thermosyphon Oil Cooling.
HOT OIL IN
FROM
SEPARATOR
120-140 F
OIL OUT
O
TO SYSTEM CONDENSER
95 F
2.5#/FT
O
395 F
36#/FT
O
3
TS RECEIVER
Figure 7

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 11
BC
A
OPT. OIL TEMP
CONTROL VALVE
HOT
REFRIGERANT
OUT
REFRIGERANT IN
COOL
COOL
OIL OUT
HOT OIL IN
LIQUID
LEVEL
STATIC HEAD
TO OVERCOME
CONDENSER
PRESSURE DROP
6 Ft.
Min.
SYSTEM
CONDENSER
SAFETY
VALVE
VAPOR
THERMOSYPHON
RECEIVER
LIQUID OVERFLOW
DRAIN TO RECEIVER
TO SYSTEM
EVAPORATOR
SYSTEM
RECEIVER
1
3
4
(Mounted below Thermosyphon
receiver level)
2
PLATE COOLER
TSOC
LIQUID INJECTION OIL COOLING
(OPTIONAL)
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 pressure gas is connected through the regulator to
the external port on the liquid injection valve to control oil
temperature.
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 3/8" line
connected into the solenoid valve provided.This gas is
required by the expansion valve external port to control
oil temperature.
It is IMPERATIVE that an uninterrupted supply of high pres-
sure 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.
The dual dip tube method uses two dip tubes in the receiver.
The liquid injection tube is below the evaporator tube to
ensure continued oil cooling when the receiver level is low.
See Figure 9.
Figure 8
1.
The thermosyphon oil cooler is supplied with the oil side piped to the compressor unit and stub ends supplied on the refrig-
erant side.
2. A three-way oil temperature control valve is required where condensing temperature is expected to go below 65°F.
3.A refrigerant-side safety valve is required in this location only when refrigerant isolation valves are installed between the cooler
and thermosyphon receiver.If no valves are used between the cooler andTSOC receiver, the safety valve on theTSOC receiver
must be sized to handle the volume of both vessels. Then, the safety valve on the cooler vent (liquid refrigerant side) can be
eliminated.
4. The system receiver must be below the thermosyphon receiver in this arrangement.
Figure 9

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 12
ECONOMIZER - HIGH STAGE (OPTIONAL)
The economizer option provides an increase in system ca-
pacity and efficiency by subcooling liquid from the condenser
through a heat exchanger or flash tank before it goes to the
evaporator. The subcooling is provided by flashing liquid in
the economizer cooler to an intermediate pressure level.The
intermediate pressure is provided by a port located part way
down the compression process on the screw compressor.
As the screw compressor unloads, the economizer port will
drop in pressure level, eventually being fully open to suc-
tion. Because of this, an output from the microprocessor
is generally used to turn off the supply of flashing liquid on
a shell and coil or DX economizer when the capacity falls
below approximately 45%-60% capacity (85%-90% slide
valve position). This is done because the compressor will
be more efficient operating at a higher slide valve position
withtheeconomizerturnedoff,thanit willat alow slidevalve
positionwiththeeconomizerturned on.Please notehowever
that shell and coil and DX economizers can be used at low
compressor capacities in cases where efficiency is not as
important as assuring that the liquid supply is subcooled.In
such cases, the economizer liquid solenoid can be left open
whenever the compressor is running.
WATER-COOLED OIL COOLING (Optional)
The plate and shell 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 if ordered in lieu of a three-way oil
temperaturevalve.Itis recommended(local codespermitting)
that the water regulator be installed on the water outlet con-
nection.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. The water
supply must be sufficient to meet the required flow.
*Based on 100 foot liquid line.For longer runs, increase line
size accordingly.
** For models 60 and 76, contact Frick engineering.
LIQUID LINE SIZES/RECEIVERVOLUME
Liquid line sizes and the additional receiver volume (quanti-
ty of refrigerant required for 5 minutes of liquid injection oil
cooling) are given in the following table:
LIQUID LINE SIZE and RECEIVERVOLUME
LINE SIZE* POUND LIQUID
RWB II SCH 80 OD PER VOLUME
MODEL ** PIPE TUBING 5 MIN. CU FT
R-717 HIGH STAGE*
100-134 3/4 – 80 2.0
177-270 1 – 140 4.0
316-480 1-1/4 – 250 7.0
R-717 BOOSTER*
100-134 1/2 – 20 0.5
177-270 3/4 – 30 1.0
316-480 1 – 40 1.5
R-22 HIGH STAGE*
100-134 1-1/4 1-1/8 290 4.0
177-270 1-1/2 1-3/8 570 8.0
316-480 2 2-1/2 1,050 14.0
R-22 BOOSTER*
100-134 3/4 7/8 44 0.6
177-270 3/4 7/8 59 0.8
316-480 3/4 7/8 92 1.2
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.See Figure 10.
Figure 10
Frick recommends a closed-loop system for the waterside
of the oil cooler. Careful attention to water treatment is es-
sential to ensure adequate life of the cooler if cooling tower
water is used. It is imperative that the condition of cool-
ing water and closed-loop fluids be analyzed regularly
and as necessary and maintained at a pH of 7.4, but not
less than 6.0 for proper heat exchanger life. After initial
start-up of the compressor package, the strainer at the inlet
of the oil cooler should be cleaned several times in the first
24 hours of operation.
In some applications, the plate and shell oil cooler may be
subjected to severe water conditions, including high tem-
perature and/or hard water conditions. This causes accel-
erated scaling rates which will penalize the performance of
theheatexchanger.A chemicalcleaningprocess willextend
the life of the Plate and Shell heat exchanger.It is important
to establish regular cleaning schedules.
Cleaning: A 3% solution of Phosphoric or Oxalic Acid is
recommended.Other cleaningsolutionscan beobtainedfrom
your local distributor, but they must be suitable for stainless
steel.The oilcooler maybecleanedin placebybackflushing
with recommended solution for approximately 30 minutes.
Afterbackflushing,rinse theheatexchangerwithfreshwater
to remove any remaining cleaning solution.
NOTE:The water-regulating valve shipped with the unit
will be sized to the specific flow for the unit.
OIL COOLER DATA TABLE
RWB II TYPICAL CONNECTION
MODEL COOLER INLET OUTLET
60 - 134 High Stage 116 Plates 3"3"
100 - 270 Booster 66 Plates 2"2"
177/222 High Stage 190 Plates 3"3"
270 High Stage 288 Plates 3"4"
316/399 Booster 56 Plates 3"3"
316/399 High Stage 136 Plates 4"5"
480 Booster 72 Plates 3"3"
480 High Stage 188 Plates 4"5"

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 13
Due to the tendency of the port pressure to fall with de-
creasing compressor capacity, a back-pressure regulator
valve (BPR) is generally required on a flash economizer
system (Figure 13) in order to maintain some preset pres-
sure difference between the subcooled liquid in the flash
vessel and the evaporators. If the back-pressure regulator
valve is not used on a flash economizer, it is possible that
no pressure difference will exist to drive liquid from the flash
vessel to the evaporators, since the flash vessel pressure
will approach suction pressure at a decreased slide valve
position.In cases where wide swings in pressure are antici-
pated in the flash economizer vessel, it may be necessary
to add an outlet pressure regulator to the flash vessel outlet
to avoid overpressurizing the economizer port, which could
result in motor overload. Example: A system feeding liquid
to the flash vessel in batches.
The recommended economizer systems are shown below.
Notice that in all systems there should be a strainer (STR)
and a check valve (VCK) between the economizer vessel
and the economizer port on the compressor. The strainer
preventsdirtfrompassing intothe compressorand thecheck
valve prevents oil from flowing from the compressor unit to
the economizer vessel during shutdown.
Other than the isolation valve
needed for strainer cleaning, it is
essential that the strainer be the
last device in the economizer line before the compres-
sor. Also, piston-type check valves are recommended
for installation in the economizer line, as opposed to
disc-type check valves.The latter are more prone to gas-
pulsation-induced failure.The isolation and check valves
and strainer should be located as closely as possible to
the compressor, preferably within a few feet.
Figure 12 - Direct Expansion Economizer System
Figure 11 - Shell and Coil Economizer System
Figure 14 - Multiple Compressor Economizer System
Figure 13 - Flash Economizer System
For refrigeration plants employing multiple compressors on
a common economizing vessel, regardless of economizer
type, each compressor must have a back-pressure regulat-
ing valve in order to balance the economizer load, or gas
flow, between compressors.The problem of balancing load
becomes most important when one or more compressors
run at partial load, exposing the economizer port to suction
pressure. In the case of a flash vessel, there is no need for
the redundancy of a back-pressure regulating valve on the
vessel and each of the multiple compressors.Omit the BPR
valve on the flash economizer vessel and use one on each
compressor, as shown in Figure 14.It is also recommended
thatthe back-pressureregulating valves,usedoneconomizer
lines, should be specified with electric shutoff option. The
electric shutoff feature is necessary to prevent flow from the
common economizer vessel to the suction side of a stopped
compressor, through the suction check valve bypass line, if
the other compressors and the common economizer vessel
are still operating and the HV2 valve on the suction bypass
is open.
For refrigeration plants using a Packaged Refrigerant Recir-
culation (PRR) unit and a direct expansion (DX) economizer
system it is necessary to operate the liquid feed solenoid on
the PRR unit and the liquid feed solenoid on the DX vessel
off of a common signal to avoid liquid overfeed on the DX
economizer system.
If multiple compressors are operated with a common econ-
omizer vessel, it is necessary to install a back-pressure
regulator valve with an electric shutoff option in the vapor
linepipedto thecompressor'seconomizerport.If an electric
shut-off is not installed in the economizer vapor line, valve
HV-2 must remain closed to avoid a gas bypass from the
economizerlinethroughthesuction checkvalvebypass,back
to the suction line on a compressor that is shut down.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 14
ECONOMIZER LOAD BALANCING
The most energy efficient manner to operate an economizer
system, when using multiple compressors on a common
economizer vessel, is to take as much of the flash gas as
possible to the compressors that are fully loaded.This can
be done in at least two ways.
1. Use the economizer output from the microprocessor to
turn off a solenoid, or to actuate the electric shutoff option
ona back-pressureregulator,basedonpercentofslidevalve
travel.This will direct all the flash vapor to the other loaded
compressors.
2. Adual-setpointback-pressureregulator valvecanbeused
ineach ofthe individualeconomizervaporlines.When acom-
pressor is running near full load, the BPR valve will operate
on the desired setpoint, or basically wide open, to minimize
pressure drop in the line. When one compressor unloads
below the slide valve position where the economizer output
on the microprocessor turns on, the dual-setpoint feature of
the regulator can be actuated by this output to control the
pressure, on the vessel side of the regulator, to be a few psi
higher.Consequently,theflash gaswillbe senttothe loaded
compressors first, until they can’t handle all the vapor and
the pressure in the vessel starts to rise. Then, some of the
vapor will go to the unloaded compressor to help maintain
the vessel at the desired pressure. An example of a back-
pressureregulatorwith electric shutoffand the dual-setpoint
feature is an R/S A4ADS.
ELECTRICAL
NOTE: Before proceeding with electrical installation,
read the instructions in the section“Proper Installation
of Electronic Equipment in an Industrial Environment”.
RWB II units are supplied with a QUANTUM control system.
Care must be taken that the controls are not exposed to
physical damage during handling, storage, and installation.
The single-box control door must be kept tightly closed to
prevent moisture and foreign matter from entry.
NOTE:All customer connections are made in the single-
box control mounted on the oil separator. This is the
ONLY electrical enclosure and it should be kept tightly
closed whenever work is not being done in it.
VOLTAGE PROTECTION
Frick®does not advise nor support the use of UPS power
systems in front of the Quantum™panel.With a UPS power
system providing shutdown protection for the Quantum™,
the panel may not see the loss of the 3-phase voltage on
the motor because the UPS could prevent the motor starter
contactor from dropping out. With the starter contactor still
energized, the compressor auxiliary will continue to feed
an “Okay” signal to the panel. This will allow the motor to
be subjected to a fault condition on the 3-phase bus.Some
fault scenarios are:
1. The3-phasebushaspower“on”and“off”inacontinuous
cyclic manner which may cause the motor to overheat
due to repeated excessive in-rush currents.
2. Motor cycling may damage the coupling or cause other
mechanical damage due to the repeated high torque
motor “bumps”.
3. Prolonged low voltage may cause the motor to stall and
overheat before the motor contactor is manually turned
off.
Undernormal conditions,the lossof 3-phase powerwillshut
the Quantum™panel down, and it will restart upon power
return. If the panel was in:
• Auto – Compressor motor will return to running as
programmed.
• Remote – The external controller would reinitialize the
panel and proceed to run as required.
• Manual – The compressor will have to be restarted
manually after the 3-phase bus fault has been cleared.
If the local power distribution system is unstable or prone to
problems, there are other recommendations to satisfy these
problems.If power spikes or low or high line voltages are the
problem,thenFrick®recommendstheuseofaSola®constant
voltage (CV) transformer with a line suppression feature. If
a phase loss occurs, then you will typically get a high motor
amp shutdown.If problems continue to exist, then an exami-
nation of the plant’s power factor may be in order.
Unless careful design failure analysis is considered in the
implementation of power systems, the alternative solutions
provide a safer and less expensive implementation.In either
case, only one Sola®may be used per compressor. Each
compressorneeds tobeindividuallyisolatedfrom eachother
through a dedicated control transformer.Sharing a common
control power source is an invitation for ground loops and
the subsequent unexplainable problems.
MOTOR STARTER PACKAGE
SBC Board damage may occur
without timer relay installed in
control panel as shown in Starter
Wiring Diagram, Figure 15.All Frick motor starter pack-
ages have the timer relay as standard.
STARTERWIRING DIAGRAM
Figure 15

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 15
Motor starter and interlock wiring requirements are shown
in the Starter Wiring Diagram.All of the equipment shown
is supplied by the installer unless a starter package is pur-
chased separately from Frick. Starter packages should
consist of:
1. The compressor motor starter of the specified HP and
voltage for the starting method specified (across-the-line,
autotransformer, wye-delta, or solid-state).
NOTE: If starting methods other than across-the-line
are desired, a motor/compressor torque analysis must
be done to ensure that sufficient starting torque is avail-
able,particularly in booster applications.Contact FRICK
if assistance is required.
2. If specified, the starter package can be supplied as a
combinationstarter withcircuit breakerdisconnect.However,
the motor overcurrent protection/disconnection device can
be applied by others, usually as a part of an electrical power
distribution board.
3. The oil pump starter with fuses, or in the case where the
compressor motor is a different voltage from the oil pump
motor,with a circuitbreaker disconnectsuitable forseparate
power feed.
4. A 2.0 KVA control power transformer (CPT) to supply 120
volt control power to the microprocessor control system and
separator oilheatersis included.Ifenvironmental conditions
require more than the usual two 500 watt oil heaters, an ap-
propriately oversized control transformer will be required. If
frequentpowerfluctuations areanticipatedorextremelynoisy
powerlinesare encountered,a regulatingcontrol transformer
should be considered. Contact FRICK for assistance.
5. For customer-supplied across-the-line starters, a shunt-
ing device must be installed across the CurrentTransformer
(terminals 3 & 4).
If the shunting device is not in-
stalled, the Analog I/O board on
the Quantum panel may be severly
damaged at start-up (see Starter Wiring Diagram,
Figure 15).
6. One each normally open compressor motor and oil pump
motorstarter auxiliarycontact shouldbe supplied.In addition
to the compressor and oil pump motor starter coils, the CT
andCPT secondaries shouldbe wiredas shownon thestart-
er package wiring diagram.The load on the control panel for
thecompressormotor startercoil shouldnot exceedaNema
size 3 starter.For larger starters, an interposing relay must
be used to switch the compressor motor starter coil(s).
NOTE: Do not install a compressor HAND/OFF/AUTO
switch in the starter package as this would bypass the
compressor safety devices.
7. The compressor motor Current Transformer (CT) is in-
stalled on any one phase of the compressor leads.
NOTE:The CT must see all the current of any one phase,
therefore in wye-delta applications BOTH leads of any
one phase must pass through the CT.
CURRENTTRANSFORMER (CT) RATIOS
The CT ratio for various motor sizes (with a 5 amp second-
ary) is given in the following table:
VOLTAGE
HP 200 230 380 460 575 2300 4160
20 100:5 100:5 50:5 50:5 50:5 - -
25 100:5 100:5 50:5 50:5 50:5 - -
30 200:5 100:5 100:5 50:5 50:5 - -
40 200:5 200:5 100:5 100:5 50:5 - -
50 200:5 200:5 100:5 100:5 100:5 - -
60 300:5 200:5 200:5 100:5 100:5 - -
75 300:5 300:5 200:5 200:5 100:5 - -
100 400:5 300:5 200:5 200:5 200:5 - -
125 500:5 400:5 300:5 200:5 200:5 - -
150 600:5 500:5 300:5 300:5 200:5 - -
200 800:5 600:5 400:5 300:5 300:5 100:5 50:5
250 800:5 800:5 500:5 400:5 300:5 100:5 50:5
300 1000:5 1000:5 600:5 500:5 400:5 100:5 50:5
350 - 1000:5 800:5 500:5 500:5 100:5 100:5
400 - - 800:5 600:5 500:5 200:5 100:5
450 - - 1000:5 800:5 600:5 200:5 100:5
500 - - 1000:5 800:5 600:5 200:5 100:5
600 - - 1200:5 1000:5 800:5 200:5 100:5
700 - - - 1200:5 1000:5 200:5 200:5
800 - - - - 1000:5 300:5 200:5
900 - - - - 1200:5 300:5 200:5
1000 - - - - - 300:5 200:5
1250 - - - - - 400:5 200:5
1500 - - - - - 500:5 300:5
MINIMUM BURDEN RATINGS
The following table gives the minimum CT burden ratings.
This is a function of the distance between the motor starting
package and the compressor unit.
BURDEN MAXIMUM DISTANCE FROM
RATING FRICK PANEL
USING # USING # USING #
ANSI VA 14 AWG 12 AWG 10 AWG
B-0.1 2.5 15 ft 25 ft 40 ft
B-0.2 5 35 ft 55 ft 88 ft
B-0.5 12.5 93 ft 148 ft 236 ft

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 16
CONTROL POWER REGULATOR
Compressorunits thatwillbeusedinareasthatsufferbrown-
outsandother significantpowerfluctuationscan besupplied
with a control power regulator.See the following illustration,
Recommended Regulator Installation.
RECOMMENDED REGULATOR INSTALLATION
REMOVE JUMPERS 6 TO 6B & 2 TO 2B
DC POWER
EMI FILTER
SUPPLY
SEE SOLA CONNECTION CHARTS FOR
INPUT & OUTPUT CONNECTIONS
6
REMOVE FERRITE TUBE
WHEN SOLA IS ADDED,
6B
6
H
NOTE: AT SOLA ASSEMBLY, MAKE WIRES 6, 2, GND, 6B, & 2B,
10 FT LONG. CUTWIRESTO LENGTH AT INSTALLATION
H5
REGULATOR
H3H4
OUTPUT
INPUT
X1
120/240 V. IN, 120 V. OUT
SOLA #63-23-112-4, 120 VA, 60 HZ
SHOWN HERE- CONSULT FRICK
FOR OTHER VOLTAGES/HZ
SOLA ENCLOSURE
GND TERM
2A6A
23
PS 1 1
LINE
LOAD
GREEN
FERRITE
TUBE
2B 2
GND LUG IN
H2 H1
LUG
X2
GREEN
GND TERM
IN MICRO 2
N
Figure 16
BATTERY BACKUP
The battery backup is used only for date and time retention
during power interruption. All setpoints and other critical
information are saved to onboard flash memory.
NOTE: It is not necessary to disconnect the battery
backup during extended downtime.

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION S70-200 IOM Page 17
OPERATION and START-UP INSTRUCTIONS
The Frick RWB II Rotary Screw Compressor Unit is an inte-
grated system consisting of six major subsystems:
1.Control Panel (See publication S90-010 O, M, & CS for
Quantum Panel and S70-200 OM for the Plus panel).
2.Compressor
3.Compressor Lubrication System
4.Compressor Oil Separation System
5.Compressor Hydraulic System
6.Compressor Oil Cooling System
7.Compressor Easy-Start System
The information in this section of the manual provides the
logical step-by-step instructions to properly start up and
operate the RWB II Rotary Screw Compressor Unit.
The following subsections must be read and understood
before attempting to start or operate the unit.
TDSH COMPRESSOR
The Frick RWB II rotary screw compressor utilizes mating
asymmetrical profile helical rotors to provide a continuous
flow of refrigerant vapor and is designed for both high pres-
sureand lowpressure applications.The compressorincorpor-
ates the following features:
1. High capacity roller bearings to carry radial loads at both
the inlet and outlet ends of the compressor.
2. Heavy-duty, four-point angular contact ball bearings
to carry axial loads are mounted at the discharge end of
compressor.
3. Balancepistonslocated intheinlet endof the compressor
toreduceaxial loadson theaxialload bearings andincrease
bearing life.
4. Moveable slide valve to provide infinite step capacity
control from 100 to 10%.
5.VOLUMIZER® volume ratio control to allow infinitely vari-
ablevolumeratiofrom2.2to5.0during compressoroperation
for all models except 480 which is 2.2 to 4.2.
6. A hydraulic unloader cylinder to operate the slide stop
and slide valve.
7. Bearing andcasing designfor350PSIdischargepressure.
This PSI rating applies only to the compressor and does
not reflect the design pressure of the various system
components.
8. All bearing and control oil vented to closed thread in the
compressor instead of suction port to avoid performance
penalties from superheating suction gas.
9. Shaft seal design to maintain operating pressure on seal
well below discharge pressure, for increased seal life.
10. Oilinjectedinto therotors tomaintain goodvolumetric and
adiabatic efficiency even at very high compression ratios.
11. Shaft rotation clockwise facing compressor, suitable for
all types of drives.SEE CAUTION.
12. Dual compressor casing design for very low airborne
noise transmission.
COMPRESSOR ROTATION IS
CLOCKWISE WHEN FACING THE
COMPRESSOR DRIVE SHAFT. THE
COMPRESSOR SHOULD NEVER BE OPERATED IN RE-
VERSE ROTATION AS BEARING DAMAGE WILL RESULT.
Figure 17
COMPRESSOR LUBRICATION SYSTEM
The lubrication system on an RWB II screw compressor unit
performs several functions:
1. Provides lubrication to bearings and seal.
2. Provides a cushion between the rotors to minimize noise
and vibrations.
3. Helps keep the compressor cool and prevents
overheating.
4. Provides an oil supply to hydraulically actuate the slide
valve and slide stop.
5. Provides oil pressure to the balance pistons to help in-
crease bearing life.
6. Provides an oil seal between the rotors to prevent rotor
contact or gas bypassing.
The compressor unit may be equipped with either a no
pump or a demand pump lubrication system. Additionally,
either system may contain dual oil filters and liquid injection,
water-cooled, or thermosyphon oil cooler for compressor
oil cooling.
NO PUMP OIL SYSTEM
The RWB II screw compressor unit is designed to be self-lu-
bricating. Oil being supplied to the compressor from the oil
separatoris atsystem headpressure.Within thecompressor,
oil porting to all parts of the compressor is vented back to a
pointin thecompressor’sbodythatis ata pressurelowerthan
compressor discharge pressure. The compressor’s normal
operation makes the compressor unit operate essentially as
its own oil pump.All oil entering the compressor is moved by
the compressor rotors out the compressor outlet and back
to the oil separator.
For normal high-stage operation an oil pump is not re-
quired.
COLD-START SYSTEM
The RWB II package is equipped with a special "cold start"
discharge check valve on the gas outlet connection of the
oil separator (see Figure 18).This valve causes the oil sepa-
rator to develop oil pressure rapidly on initial start in order to
lubricate thecompressor without requiringanoil pump,even
in cold ambient temperatures with all pressures equalized.

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 18
For high-stage packages, the cold-start valve is equipped
with a large spring that creates 30 psi of pressure in the oil
separator (above suction pressure), for lubrication of the
compressor.
DO NOT ATTEMPT TO SERVICE THE COLD START
VALVE. PLEASE CONTACT THE FRICK SERVICE
DEPARTMENT.
Once the compressor is running it will begin to force gas to
the condenser at connection P2.As the condenser heats up
it will begin to rise in pressure as the compressor suction
pulls down in pressure. As soon as differential pressure is
developed between the condenser and suction, these pres-
suresact acrossapistoninsidethe cold-startvalveto partially
overcome the spring force. When the differential pressure
reaches and exceeds 30 psi, the piston fully overcomes the
spring force and powers the valve fully open for very low
operating pressure drop.
For booster applications, the valve is equipped with a lighter
spring which produces 15 psi oil pressure above suction
pressure before it fully powers open.
The RWB II package is also equipped with a suction check
valve bypass. The oil separator will slowly bleed down to
systemsuction pressurewhen theunit isstopped.This allows
the compressor drive motor to have an easier start, and the
discharge check valve will seat more tightly. See the "SUC-
TION CHECK VALVE BYPASS" section for operation.
NOTE: For alarm descriptions and shutdown or cutout
parameters, see publication S90-010 O.
COLD STARTVALVE
DEMAND PUMP OIL SYSTEM
This system is designed to provide adequate compressor
lubrication forsomehigh stageapplications thatoperate with
low differential pressure across the compressor suction and
discharge and all booster applications.
During the period from start-up to normal operation the oil
pressure alarm and oil pressure cutout setpoints will vary
according to formulas built into the microprocessor control
program.
NOTE: For alarm descriptions and shutdown or cutout
parameters, see publication S90-010 O.
COMPRESSOR OIL SEPARATION SYSTEM
The RWB II is an oil flooded screw compressor. Most of the
oildischarged bythecompressor separatesfromthegasflow
in the oil charge reservoir.Some oil, however, is discharged
as a mist which does not separate readily from the gas flow
and is carried past the oil charge reservoir. One or more
coalescer filter elements then COALESCE the oil mist into
droplets which fall to the bottom of the coalescer section of
the oil separator. The return of this oil to the compressor is
controlledbyathrottlingvalveonbothhighstageandbooster
applications (see Figure 19).
NOTE: Open throttling valve only enough to keep co-
alescer end of separator free of oil.
Thesightglasslocatednear thebottom ofthe coalescersec-
tion of the oil separator should remain empty during normal
operation. If an oil level develops and remains in the sight
glass, a problem in the oil return separation system or com-
pressor operation has developed.Refer to MAINTENANCE
for information on how to correct the problem.
NOTE: Normal operating level is midway between the
top sight glass and bottom sight glass.
OIL SEPARATION SYSTEM
Figure 18 Figure 19

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION S70-200 IOM Page 19
COMPRESSOR HYDRAULIC SYSTEM
The compressor hydraulic system moves the movable slide
valve(MSV)toloadand unloadthe compressor.Italsomoves
the movable slide stop (MSS) to increase or decrease the
compressor’s volume ratio (Vi).
The hydraulic cylinder located at the inlet end of the TDS
compressor serves a dual purpose.It is separated by a fixed
bulkhead into two sections.The movable slide valve (MSV)
section is to the left of the bulkhead and the movable slide
stop(MSS)to theright.Bothsectionsare considereddouble
acting hydraulic cylinders as oil pressure moves the pistons
in either direction.
Both sections are controlled by double-acting, four-way
solenoid valves which are actuated when a signal from the
appropriate microprocessor output energizes the solenoid
valve.
Compressor Loading: The compressor loads when MSV
solenoidYY2 is energized and oil flows from the oil manifold
throughvalveportsPand Btocylinder portSC-2and enters
the load side of the cylinder.Simultaneously, oil contained in
the unload side of the cylinder flows out cylinder port SC-1
through valve ports A and T to compressor closed thread
port.
Compressor Unloading: The compressor unloads when
MSV solenoid YY1 is energized and oil flows from the oil
manifold through valve ports P and A to cylinder port SC-1
and enters the unload side of the cylinder. Simultaneously,
oil contained in the load side of the cylinder flows out com-
pressorport SC-2throughvalveports BandTto compressor
closed thread port.
Figure 20
NOTE: High Stage Operation: An alternative piping ar-
rangement has been provided to increase slide valve
response time during high stage operation.
Higher operating pressures will slow the compressor un-
loading response time. Unloading response time can be
increased by closing valve 1 (oil manifold pressure) and
openingvalve2 tocompressor suction pressure.See Figure
20. NEVER OPEN VALVE 1 AND VALVE 2 AT THE SAME
TIME DURING COMPRESSOR OPERATION.
VOLUMIZER® VOLUME RATIO CONTROL
Vi Increase
The volume ratio Vi is increased when MSS solenoid YY3
is energized and oil flows from the oil manifold through
valve ports P and A to cylinder port SC-3 and enters the
increase side of the cylinder. Simultaneously, oil contained
in the decrease side of the cylinder flows out cylinder port
SC-4 through valve ports B and T to compressor closed
thread port.
Vi Decrease
The volume ratio Vi is decreased when MSS solenoid YY4
is energized and oil flows from the oil manifold through
valve ports P and B to cylinder port SC-4 and enters the
decrease side of the cylinder.Simultaneously, oil contained
in the increase side of the cylinder flows out cylinder port
SC-3 through valve ports A and T to compressor closed
thread port.
MSV and MSS HYDRAULIC CYLINDER and SOLENOIDVALVES

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 20
COMPRESSOR OIL COOLING SYSTEMS
TheRWBII unitcan beequipped withone ofseveralsystems
forcontrollingthecompressor oiltemperature.Theyare single
or dual-port liquid injection, or thermosyphon and water-
cooled oil coolers. Each system is automatically controlled,
independent of compressor loading or unloading.
Oil cooling systems should maintain oil temperature within
the following ranges for R-717 and R-22:
Liquid Injection External*
Oil Cooling Oil Cooling
130 - 170°F 120 - 160°F
* Thermosyphon oil cooling (TSOC) or Water-cooled oil
cooling (WCOC).
SINGLE-PORT LIQUID INJECTION
The single-port liquid injection system is designed to permit
liquid refrigerant injection into one port on the compressor
at any given moment and operates as outlined.
Solenoid valve SV5 is energized by the microprocessor
when the temperature sensor, installed in the oil manifold,
exceeds the LICO set point. High pressure liquid refrigerant
is then supplied to the temperature control valve (TCV).The
temperature control valve is equalized to a constant back
pressure by the differential pressure control valve (PDCV).
The differential pressure control valve uses discharge gas
to maintain downstream pressure. The gas downstream of
the differential pressure control valve is bled off to the com-
pressor suction to ensure steady and constant operation of
the valve.
RWB II BOOSTER OR SWING DUTY
APPLICATION
Discharge gas from the high stage compressor is required
to assist the differential pressure control valve (PDCV) in
providingthetemperaturecontrol valve(TCV) withaconstant
back pressure.
A solenoid valve SV6 is installed before the differential
pressure control valve (PDCV) to prevent migration of high
pressure gas during shutdown. A Frick-installed timer limits
the high pressure gas to only thirty seconds duration, since
intermediate gaspressure andspringtension aresufficient to
maintain closure on unit shutdown.A metering valve is also
provided for use as a service valve and to allow discharge
gas flow regulation to prevent excessive force and resulting
closure “hammering”.
A field-installed 1/4 inch OD tubing connection is required
betweenthe highstagecompressor dischargepiping line(or
receiver) and the check valve.
DUAL-PORT LIQUID INJECTION
The dual-port liquid injection system is designed to obtain
the most efficient compressor performance at high and low
compressionratios bypermitting injectionofliquidrefrigerant
into one of two ports optimally located on the compressor.
This minimizes the performance penalty incurred with liquid
injection oil cooling.
The dual-port system contains all the components of the
single-port system with the addition of a double acting so-
lenoid valve SV7 and operates as outlined.
SolenoidvalveSV5is energizedbythe microprocessorwhen
thetemperature sensor, installedin theoilmanifold,exceeds
the LICO set point.Liquid refrigerant is then passed through
thetemperaturecontrol valve(TCV) to thedouble-acting so-
lenoid valve SV7.Depending on the compressor’s operating
volume ratio (Vi), the microprocessor will select the flow of
the liquid refrigerant to either compressor port SL-1 or SL-2,
whichever is more efficient.
When the compressor operates BELOW 3.5Vi, compressor
port SL-1 supplies the liquid cooling. When the (Vi) rises
ABOVE 3.5 Vi, port SL-2 supplies the liquid cooling.
Thetemperature controlvalveisequalizedto aconstant back
pressure by the differential pressure control valve (PDCV).
Both the differential pressure control valve (PDCV) and
the double-acting solenoid valve SV7 use discharge gas to
maintaindownstreampressure.The gasdownstream ofboth
valvesis bledoff tothecompressor suctiontoensure steady
and constant operation of the valves.
LIQUID INJECTION ADJUSTMENT
PROCEDURE
Adjustments must be made to ensure the oil is at the proper
temperature. When the adjustments have been made cor-
rectly, the oil temperature, the discharge temperature and
the temperature of the oil in the separator should all be ap-
proximately the same. (Refer to P&I Diagram)
Carefully insert The bulb from the thermal expansion valve
(TXV ) into the well in the discharge pipe between the com-
pressor and the oil separator.Then open the valve to the oil
separator high pressure connection.
Next, open the refrigerant supply valve, remove the cap on
the pressure regulating valve (PCV ), and close the adjust-
ing valve.
For low temperature oil – 125° to 135°F
Aftertheunit hasbeen started,wait fortheoil temperatureto
reach122°F.Thisis thepreprogrammedtemperature toopen
the liquid feed solenoid in the liquid injection supply line.
Open the adjusting valve only until the needle on the gauge
begins to move a very small amount.
Next, adjust the pressure regulating valve to approximately
80 psig by turning the adjustment ring inside the top of the
valve with a 5/16" Allen wrench.Turn the wrench clockwise
to raise the oil temperature, and counterclockwise to lower
the oil temperature.
After the adjustment s been, made wait until the oil and
discharge temperatures have had a chance to stabilize
before readjusting.The end result should be between 135°
and 140°F.
For high temperature oil – 160° to 170°F
Aftertheunit hasbeen started,wait fortheoil temperatureto
reach122°F.Thisis thepreprogrammedtemperature toopen
the liquid feed solenoid in the liquid injection supply line.
Open the adjusting valve only until the needle on the gauge
begins to move a very small amount.