Frick RWB II 496 Owner's manual

Installation - Operation - Maintenance
ROTARY SCREW COMPRESSOR UNITS
ALL REFRIGERANTS
MODELS
60 through 856
Use for 496 – 856 only!
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 OFTHE UNIT.
S70-200 IOM/NOV 2000
File: SERVICE MANUAL - Section 70
Replaces: S70-200 IOM/DEC 99
Dist: 3, 3a, 3b, 3c

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION - OPERATION - MAINTENANCE
S70-200 IOM
Page 2 496–856 ONLY! Contents
PREFACE .........................................................................3
DESIGN LIMITATIONS......................................................3
JOB INSPECTION ............................................................3
TRANSIT DAMAGE CLAIMS ............................................3
COMPRESSOR and UNIT IDENTIFICATION...................3
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 OIL .........................................................9
OIL CHARGE ....................................................................9
OIL HEATER(S) ..............................................................10
OIL FILTER(S) ................................................................10
LIQUID INJECTION OIL COOLING................................10
LIQUID LINE SIZES/RECEIVER VOLUME ....................10
WATER-COOLED OIL COOLING (OPTIONAL) .............11
THERMOSYPHON OIL COOLING (OPTIONAL) ...........11
ECONOMIZER - HIGH STAGE (OPTIONAL) .................13
ECONOMIZER LOAD BALANCING ...............................14
ELECTRICAL ..................................................................14
MOTOR STARTER PACKAGE ........................................14
CONTROL POWER REGULATOR .................................15
CURRENT TRANSFORMER (CT) RATIOS....................15
MINIMUM BURDEN RATINGS .......................................15
BATTERY BACKUP ........................................................15
OPERATION and START-UP INSTRUCTIONS ..............16
TDSH COMPRESSOR ...................................................16
COMPRESSOR LUBRICATION SYSTEM......................16
PRELUBE OIL SYSTEM.................................................16
CYCLING FULL-LUBE OIL SYSTEM .............................17
COMPRESSOR OIL SEPARATION SYSTEM ................17
FULL-LUBE OIL SYSTEM ..............................................17
COMPRESSOR HYDRAULIC SYSTEM.........................18
VOLUMIZER® VOLUME RATIO CONTROL...................18
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
SUCTION CHECK VALVE...............................................21
SUCTION CHECK VALVE BYPASS................................21
LOW AMBIENT OPERATION .........................................21
POWER ASSIST KIT ......................................................21
COMPRESSOR PRESTART CHECKLIST .....................22
INITIAL START-UP .........................................................23
INITIAL START-UP PROCEDURE..................................23
NORMAL START-UP PROCEDURE ..............................23
GENERAL INFORMATION .............................................24
NORMAL MAINTENANCE OPERATIONS .....................24
GENERAL MAINTENANCE............................................24
COMPRESSOR SHUTDOWN and START-UP ...............24
GENERAL INSTRUCTIONS FOR REPLACING
COMPRESSOR UNIT COMPONENTS...................25
OIL FILTER (OF-1) MAIN SINGLE/DUAL .......................25
OIL FILTER/STRAINER -
PRELUBE OIL PUMP ..............................................25
STRAINER - FULL LUBE OIL PUMP .............................26
STRAINER - LIQUID INJECTION...................................26
COALESCER FILTER ELEMENT(S) ..............................26
CHANGING OIL ..............................................................27
RECOMMENDED MAINTENANCE PROGRAM.............27
VIBRATION ANALYSIS ...................................................27
MOTOR BEARINGS .......................................................27
OIL QUALITY and ANALYSIS .........................................27
OPERATING LOG ...........................................................28
MAINTENANCE SCHEDULE .........................................29
TROUBLESHOOTING GUIDE ........................................30
ABNORMAL OPERATION
ANALYSIS and CORRECTION................................30
PRESSURE TRANSDUCERS - TESTING .....................31
PRESSURE TRANSDUCERS - REPLACEMENT ..........31
SV POSITION POTENTIOMETER
REPLACEMENT AND ADJUSTMENT ....................32
VOLUMIZER® POTENTIOMETER .................................33
REPLACEMENT AND ADJUSTMENT ...........................33
TEMPERATURE and/or PRESSURE
ADJUSTMENT.........................................................33
TROUBLESHOOTING THE RWB II
COMPRESSOR .......................................................34
SEPARATION SYSTEM...........................................34
HYDRAULIC SYSTEM ............................................35
PRELUBE PUMP SYSTEM .....................................36
FULL TIME PUMP SYSTEM ...................................36
LIQUID INJECTION OIL COOLING SYSTEM.........37
THERMAL EXPANSION VALVES ...................................38
JORDAN TEMPERATURE REGULATOR VALVE ...........39
BARE COMPRESSOR MOUNTING...............................39
BALANCE PISTON PRESSURE REGULATOR ............39
P & I DIAGRAM, 60 – 270 ..............................................40
PROPER INSTALLATION OF ELECTRONIC
EQUIPMENT............................................................48
OPERATING LOG SHEET .............................................51
RECOMMENDED SPARE PARTS .................................52

RWB II ROTARY SCREW COMPRESSOR UNITS
GENERAL INFORMATION S70-200 IOM Page 3
496–856 ONLY!
PREFACE
This manual has been prepared to acquaint the owner and
serviceman with the INSTALLATION, OPERATION, and
MAINTENANCEproceduresas recommended byFrickCom-
pany for RWB II Rotary Screw Compressor Units.
For information about the functions of the electrical control
panel,communications,specifications,and wiringdiagrams,
see S90-010 OM (
Quantum panel) or S70-200 OM (Plus
panel).
It is most important that these units be properly applied to
an adequately controlled refrigeration system.Your authori-
zed Frick Company representative should be consulted for
his expert 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 and application, theequipment
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
practicesandlocalcodes,suchasthoseoutlinedinASHRAE
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 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 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
Company, Sales AdministrationDepartment, inWaynesboro,
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
FRICKSALESORDER NUMBERS from these dataplates.
UNIT DATA PLATE
COMPRESSOR DATA PLATE

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 4 496–856 ONLY!
ALLOWABLE FLANGE LOADS
NOZ. MOMENTS (ft-lbf) LOAD (lbf)
SIZE AXIAL VERT. LAT. AXIAL VERT. LAT.
NPS MRMCMLPV
CVL
1 252525505050
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
and a mass is required to effectively dampen these rela-
tively high frequency vibrations.
Firmlyanchoring the compressor packageto a suitablefoun-
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
arrangementdrawingsfrom FrickCo.todeterminethemount-
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-
creteandhousekeepingpadsarerecommended. Anchorbolts
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 expan-
sion-type epoxy grout must be worked under all areas of the
base with no voids and be allowed to settle with a slight out-
ward slope so oil and water can run off of the base.
Wheninstalling on a steelbase, thefollowingguidelinesshould
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.
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
vibrationdirectlytothestructure. However,thismayincrease
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, 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 tur-
bine drive.
When applying screw compressors at high pressures, the
customer must be prepared for package vibration and noise
higherthanthevaluespredictedfornormalrefrigeration duty.
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.
RIGGING and HANDLING
THISSCREWCOMPRESSORPACK-
AGEMAYBETOP-HEAVY.USECAU-
TION 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
liftingpointshould be made to compensateformotor 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.
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
takingoffthenutsandboltsthatarefasteningtheunitmount-
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.
Spread the skid to clear the unit mounting support, then lower
the unit to the surface.Repeat procedure on opposite end.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 5
496–856 ONLY!
DBZ-B HUB FACE MAXIMUM TOTAL CLAMP BOLT TORQUE
COUPLING SPACING +/- INDICATOR READING ft-lb Nm
SIZE in. mm in. mm in. mm LUB DRY LUB DRY
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
shaftsare properlyspacedforthecouplingbeing used. Refer
to the coupling data tables for the applicable dimension
(pages 5 and 6).
CHECKING MOTOR/COMPRESSOR ROTATION
Make sure coupling hubs are tight-
enedtothe shaft beforerotatingthe
motor to prevent them from flying
off and possibly causing serious injury or death.
COMPRESSOR ROTATION IS
CLOCKWISE WHEN FACING
THE END OF THE COMPRES-
SORSHAFT.UnderNO conditions
should the motor rotation be
checked with the coupling center
installed as damage to the com-
pressor may result. Bump the mo-
tor to check for correct compres-
sorrotation.After verification,install gear ordisk 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 gear which floats freely between the hubs. In-
stall 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. Hold the elastomeric gear between the hubs and slide
both hubs onto the gear to fully engage the mating teeth.
Center the gear and hub assembly so there is equal en-
gagement 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
giveninthe CH DataTable.DO NOT USE ANY LUBRICANT
ONTHESE BOLTS.
4. Proceed to Coupling Alignment.
DBZ-B COUPLING – TheThomas DBZ-B coupling is used
on applications above 600 HP and with sleeve bearing
motorsthatdo not haveaxial end float constraint.TheDBZ-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 oc-
cur 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 onthe spin-
ning motor shaft.
If the motor is coupled to the compressor using a fixed-end-
play coupling, such as a DBZ-B coupling, and the motor is
not properly centered, additional thrust loads will be trans-
mitted to the compressor bearings that could result in pre-
mature 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.
CH COUPLING HUB MAXTOTAL CLAMP KEYWAY
COUP- BETWEEN SHAFT SPACING SHAFT ENGAGEMENT FACE INDICATOR BOLT SETSCREW
LING MIN* MAX MIN MAX SPACING READING TORQUE TORQUE
SIZE in. mm in. mm in. mm in. mm in. mm in. mm ft-lb Nm ft-lb Nm
8 3-13/16 96.8 4-0 101.6 1 25.4 1-13/16 46.0 1-1/8 28.6 .004 .104 55 74.6 13 17.6
9 4-5/16 109.5 5-7/16 138.1 1 25.4 2-3/16 61.9 1-7/16 36.5 .004 .104 55 74.6 13 17.6
10 4-5/16 109.5 6-3/8 161.9 1-1/4 31.8 2-9/16 65.1 1-11/16 42.9 .004 .104 130 176.3 13 17.6
11 4-7/8 123.8 5-7/8 149.2 2 50.8 2-7/8 73.0 1-7/8 47.6 .004 .104 130 176.3 13 17.6
226 3-13/16 96.8 1/64 .40 .003 .076 22 43 29.8 58.3
263 4-5/16 109.5 1/32 .79 .004 .102 33 63 44.7 85.4
301 4-7/8 123.8 1/32 .79 .004 .102 50 95 67.8 128.8
351 5-7/8 149.2 1/32 .79 .004 .102 95 175 128.8 237.3
401 6-11/16 169.9 1/32 .79 .004 .102 120 200 162.7 271.2
DBZ-B COUPLING DATATABLE

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 6 496–856 ONLY!
BP HUB FACE * DISC PACK CLAMP BOLT
SERIES SPACING BOLT TORQUE TORQUE DRY
SIZE in. mm ft-lb Nm ft-lb Nm
BP48 4.88 124 40 54 41 56
BP53 5.88 150 60 81 65 88
BP58 6.00 152 120 163 100 136
BP58 6.69 170 120 163 100 136
BP63 7.00 179 120 163 100 136
* 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 lock-
nuts. Alternately tighten each locknut as you would the lug
nuts on an automobile. NOTE: ALWAYS TURN THE NUT.
NEVERTURNTHE 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 locknutswill generally fallinthelowerrange;
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 coupling is
alsousedon applications above600HP.Ithastwodrivehubs,
a center spool, and disc packs which are bolted between the
center spool and each drive hub.A center spool and two flex-
ible steel disc packs serve as the drive element.These three
parts,situatedbetweenthemotor and compressor hubs,pre-
ventaxialendfloat betweenthemotor and compressorshafts.
Endfloattends to occur with sleevebearing motors.Themag-
neticcenter of the sleeve bearing motorsmustbedetermined
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
transmittedtothecompressorbearings.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 OR-
DER. 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-
iblesteeldisc packsasthe drive element.Thesethree 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.
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 found on
pages 7 and 8 of this manual, disassemble the BP Series
coupling noting the arrangement of bolts, washers, and
nuts as THEY MUST BE REPLACED IN THE SAME OR-
DER. 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. Slide the coupling hubs on their respective shafts.
3. Reassemble the coupling with the disc packs and the
center spool. Ensure that they are reassembled exactly as
theyweredisassembled.Torquediscpackhardware to speci-
fication in BP Series Coupling Data Table.
BP SERIES COUPLING DATATABLE
225 5 127.0 1/32 .914 .004 .102 .004 .102 25 34.0
262 5 127.0 1/32 .914 .004 .102 .004 .102 30 40.7
312 5-1/2 139.7 3/64 1.295 .004 .102 .004 .102 40 54.2
350 6 152.4 3/64 1.295 .004 .102 .004 .102 95 128.8
375 7 177.8 1/16 1.574 .004 .102 .004 .102 130 176.3
425 7 177.8 1/16 1.574 .004 .102 .004 .102 175 237.3
450 8 203.2 1/16 1.574 .004 .102 .004 .102 200 271.2
500 9 228.6 5/64 2.083 .004 .102 .004 .102 260 352.5
COUP- HUB FACE MAX TOTAL INDICATOR READING CLAMP BOLT
LING SPACING +/- ANGULAR PARALLEL TORQUE (LUBE)
SIZE in. mm in. mm in. mm in. mm ft-lb Nm

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 7
496–856 ONLY!
FIG. 1 - ANGULAR MISALIGNMENT
COUPLING ALIGNMENT PROCEDURE
The life of the compressor shaft seal and bearings, as well
as the life of the motor bearings, is dependent upon proper
coupling alignment.Couplings may be aligned at the factory
but realignment MUST ALWAYS be done on the job site
after the unit is securely mounted on its foundation. Initial
alignment must be made prior to start-up and rechecked
after a few hours of operation. Final (HOT) field alignment
can only be made when the unit is at operating temperature.
After final (HOT) alignment has been made and found to be
satisfactory for approximately one week, the motor may be
dowelled to maintain alignment.
NOTE: Frick recommends cold aligning the motor .005"
high. This cold misalignment compensates for thermal
growth when the unit is at operating temperature.
The following procedure is applicable to both the CH and
DBZ-B couplings.Dial indicators are to be used to measure
the angular and parallel shaft misalignment.Coupling align-
ment is attained by alternately measuring angular and par-
allel misalignment and repositioning the motor until the mis-
alignment 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 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.
NOTE:When DBZ-B couplings are used on motors with
sleeve bearings, it is necessary to secure the two cou-
pling 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 indicator at zero when viewedat the 12 o’clock
position, as shown in Fig. 2.
4. Rotate both coupling hubs together 180O(6 o’clock posi-
tion), as shown in Fig. 3. At this position the dial indicator
will show TOTAL angular misalignment.
NOTE:The use of a mirror is helpful in reading the indi-
cator dial as coupling hubs are rotated.
FIG. 2 - DIAL INDICATOR ATTACHED (AT 12 O'CLOCK)
FIG. 3 - DIAL INDICATOR AT 6 O'CLOCK
4. Key and secure the hubs to the shafts by tightening the
clamping bolts.Make sure that the keyways are offset 180O
to maintain balance.
5.Torquethe clampingbolts of both hubs to the torque value
given in the Data Table. DO NOT USE ANY LUBRICANT
ONTHESE BOLTS.
6. Proceed to Coupling Alignment.
5. Loosen motor anchor bolts and move or shim motor to
correct the angular misalignment.
Afteradjustmentshavebeenmade forangularmisalignment
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.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 8 496–856 ONLY!
PARALLEL ALIGNMENT
6. To check parallel alignment, as shown in Fig.4, reposition
dial indicator so the stem is in contact with the rim of the
compressor hub, as shown in Fig. 5.
Check the dial indicator to be sure that the indicator stem is
slightly loaded so as to allow movement in both directions.
7. Check parallel height misalignment by setting dial indica-
tor at zero when viewed at the 12 o'clock position. Rotate
both coupling hubs together 180O(6 o'clock position).At this
position the dial indicator will show TWICE the amount of
parallel height misalignment.
8. Loosen motor anchor bolts and add or remove shims un-
der the four motor feet until parallel height misalignment is
withinspecifiedtolerancewhenanchor bolts are retightened.
CARE MUST BE USEDWHEN COR-
RECTING FOR PARALLEL MIS-
ALIGNMENTTOENSURETHATTHE
AXIALSPACINGAND ANGULAR MISALIGNMENT IS NOT
SIGNIFICANTLY DISTURBED.
9. After the parallel height misalignment is within tolerance,
repeatSteps 1through 5 until angularmisalignment is within
specified tolerance.
10. Check parallel lateral misalignment by positioning dial
indicator so the stem is in contact with the rim of the com-
pressor hub at 3 o'clock, as shown in Fig. 6.
Set indicator at zero and rotate both coupling hubs together
180O(9 o'clock position), as shown in Fig. 5.
Adjust parallel lateral misalignment using the motor adjust-
ing screws until reading is within specified tolerance.
11. Recheck angular misalignment and realign if necessary.
12.Tighten motor anchor bolts and rotate bothcouplinghubs
together, checking the angular and parallel misalignment
through the full 360Otravel at 90Oincrements. If dial read-
ings 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 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

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 9
496–856 ONLY! COMPRESSOR 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 in
Frick compressors must be ap-
proved in writing by Frick engineer-
ing 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 (For 496 – 856,
sight glass is located in the lower portion of the vertical
separator). Normal operating level is midway between the
top sight glass and bottom sight glass. The following table
gives the approximate oil charge quantity.
TABLE - BASIC OIL CHARGE (Gal)
* Includes total in oil sep-
arator and piping. Add
additional for oil cooler.
Addoil byattachingthe end of asuitablepressure type hose
to the oil charging valve, located on the top of the oil sepa-
rator on the compressor end of the separator.Using a pres-
sure-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 in the coalescing end of
the separator near the discharge connection should
remain empty.
60 55
76 55
100 85
134 85
177 165
222 165
270 165
316 230
399 230
480 135
496 (1)
676 (1)
856 (1)
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 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 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 COMPRESSOR.
OIL PUMP COUPLING
Compressor units with prelube and direct motor/pump
coupled pumps need no pump/motor coupling alignment
since this is maintained by the close-coupled arrangement.
Some units utilize full and cycling lube pumps which have
the motor separate from the pump. These must be checked
for alignment due to possible misalignment which may be
causedbyshippingand handling.Adjustments forthat maxi-
mummisalignment is lessthan 0.010"Total Indicator Runout
(T.I.R.).Failureto align the couplingmaycause serious dam-
age to the pump, shaft seal, coupling, and motor bearings.
Use the same procedure as compressor/motor coupling
alignment.
HOLDING CHARGE AND STORAGE
Each RWB II compressor unit is pressure and leak tested at
theFrickfactoryandthen thoroughly evacuatedandcharged
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
onseparatorand external 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
corrosiondamage. Reasonableconsiderationmustbe 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 periodically.
BASIC*
CHARGE
(gal.)
RWB II
PLUS
MODEL
ADDITIONAL FOR OIL COOLER
REQ'D. (gal.)SIZE (in.)
6 X 60 6
8 X 60 10
6 X 120 12
8 X 120 20
10 X 120 28
12 X 120 39
16 X 120 45
1. Oil Basic Oil Charge
Sep.
Dia. Vertical Horiz.
42" 165 gal. 245 gal.
48" 220 gal. 330 gal.
54" 275 gal. –
60" 385 gal. –
66" 385 gal. –
72" 385 gal. –

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 10 496–856 ONLY!
OIL HEATER(S)
Standard units are equipped with 2 or 3 500 watt oil heat-
ers, providing sufficient heat to maintain the oil temperature
for most indoor applications during shutdown cycles to per-
mit safe start-up. Should additional heating capacity be re-
quired because of low ambient, contact Frick Company.The
heater(s) is energized only when the unit is not in operation.
Do not energize the heater(s) when
there is no oil in the unit, the heat-
er(s) will burn out. The oil heater(s)
will be energized whenever 120 volt control power is ap-
plied to the unit and the compressor is not running,
unless the 16 amp circuit breaker in the micro enclosure
is turned off.
OIL FILTER(S)
Use of filter elements other than
Frick must be approved in writing
by Frick engineering or warranty
claim may 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.
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
valvebulbintothe thermowellprovided in the separator.High
pressure gas is connected through the regulator to the ex-
ternal port on the liquid injection valve to control oil tem-
perature. NOTE:There is NO high pressure gas connec-
tion on models 496 – 856. 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 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 sufficient-
ly to retain a 5 minute supply of refrigerant for oil cooling.
The evaporator supply must be secondary to this consider-
ation.Two methods of accomplishing this are shown.
The Dual Dip Tube method uses two dip tubes in the re-
ceiver. The liquid injection tube is below the evaporator tube
to ensure continued oil cooling when the receiver level is
low.
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.
*Based on 100 foot liquid line. For longer
runs, increase line size accordingly.
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
RWB II LINE SIZE * POUND LIQUID
PLUS SCH 80 OD PER VOLUME
MODEL PIPE TUBING 5 MIN. CU FT
R-717 HIGH STAGE *
60-76 3/4 – 50 1.5
100-134 3/4 – 80 2.0
177-270 1 – 140 4.0
316-480 1-1/4 – 250 7.0
496-676 2 – 420 11.5
856 2 – 650 18.0
R-717 BOOSTER *
60-76 1/2 – 10 0.5
100-134 1/2 – 20 0.5
177-270 3/4 – 30 1.0
316-480 1 – 40 1.5
496-676 1 – 70 2.0
856 1-1/4 – 125 3.5
R-22 HIGH STAGE *
60-76 1 1-1/8 170 2.5
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 1050 14.0
496-676 3 2-5/8 1780 25.0
856 3 2-5/8 1960 27.0
R-22 BOOSTER *
60-76 3/4 5/8 33 0.4
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
496-676 1-1/4 1-1/8 156 2.2
856 1-1/4 1-1/8 266 3.7
DUAL DIPTUBE METHOD
LEVEL CONTROL METHOD

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 11
496–856 ONLY!
WATER-COOLED OIL COOLING (OPTIONAL)
The shell and tube type water-cooled oil cooler is mounted
on the unit complete with all oil piping. The customer must
supply adequate water connections and install the two-way
water regulating valve. It is recommended that (local codes
permitting) the water regulator be installed on the 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 suffi-
cient to meet the required flow.
Itis imperativethat the condition of cooling waterand closed
loop fluids be analyzed and maintained regularly and as
necessary to prevent corrosion of heat exchanger surfaces.
The oxygen content of river water and some other cooling
water sources will oxidize steel tubes and cause premature
failure. Careful attention to water treatment is essential to
ensure adequate life of steel cooler tubes if cooling tower
water is used.The condition of heat exchanger tubes should
be checked semiannually to minimize the potential for leaks.
NOTE:The water regulating valve shipped with the unit
will be sized to the specific flow for the unit.
2. A shell and tube oil cooler with:
Shell Side: Oil 400 lb. design
Tube Side: Refrigerant 400 lb. 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
tube side up to the Thermosyphon receiver liquid level.
Hot oil (above the liquid temperature) flowing through the
cooler will cause some of the refrigerant to boil and vapor-
ize in the tubes.The vapor rises in the return line.The den-
sity of the refrigerant liquid/vapor mixture in the return line is
considerably less than the density of the liquid in the supply
line. This imbalance provides a differential pressure that
sustains a flow condition to the oil cooler. This 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 single-pass oil
coolers and flow rates based on 3:1 overfeed.
The liquid/vapor returned from the cooler is separated in
the receiver.The vapor is vented to the condenser inlet and
need only be reliquified since it is still at condenser pres-
sure.
HOT OIL IN FROM SEPARATOR
120-140 F OIL OUT
O
TO SYSTEM CONDENSER
95 F
36#/FT
O
3
95 F
36#/
FT
O
3
TS RECEIVER
THERMOSYPHON OIL COOLING (OPTIONAL)
Thermosyphonoilcoolingisaneconomical,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 vessel cooling the oil. The
vapor, at condensing pressure, is vented to the condenser
inlet and reliquified. This method is the most cost effective
of all currently applied cooling systems since no compres-
sor capacity is lost or compressor power penalties incurred.
The vapor from the cooler need only be condensed, not
compressed. Refrigerant flow to the cooler is automatic,
driven by the thermosyphon principle and cooling flow in-
creases 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.
OIL COOLER DATATABLE
SIZE - Inches APPROX
WATER FLOW
COOLER WATER CONN RANGE (GPM)
5 Feet and 10 Feet Lengths
6" 1-1/2 NPT 22 - 57
6"(1) 1-1/2 NPT 11 - 29
8" 2-1/2 NPT 40 - 108
8"(1) 2-1/2 NPT 20 - 54
10 Feet Length
10" 3 NPT 70 - 187
12" 4 NPT 100 - 279
16" 5 NPT 180 - 480
1. 4-pass design.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 12 496–856 ONLY!
OILTEMPERATURE CONTROL - Oil temperature will gen-
erally run about 15 - 35OF above condensing temperature.
In many cases, an oil temperature control is not required if
condensing temperature is above 65OF 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 shell and tube-type thermosyphon oil
cooler with oil-side piping and a thermostatically controlled
mixingvalve(if ordered) are factorymounted and 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 receiv-
er, 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.
TSOC ANDWCOC OIL SIDE SAFETY RELIEF - Compres-
sor units assembled after January 1995, which have valves
in the oil piping to isolate the oil cooler from the oil separator
for servicing, may have factory installed piping to relieve the
shell side (oil side) safety valve directly into the oil separa-
tor, as shown in the P & I diagrams section.
This arrangement uses a special UV stamped safety valve
rated for liquid and vapor relief.The safety valve is designed
for 500 psi DWP and is set to relieve at 75 psi delta P.The
safety valve piping contains flanged connections should the
valve require maintenance or replacement.
EXTRA CAUTION SHOULD BE
USED WHEN SERVICING AN OIL
SEPARATOR WITH THIS AR-
RANGEMENT. IF THE OIL COOLER IS VALVED OFF
FROM AN OIL SEPARATOR WHICH HAS BEEN EVACU-
ATED FOR SERVICING,THENTHE OIL COOLER COULD
RELIEVE INTOTHE SEPARATORVESSEL IFTHE 75 PSI
DELTA P SETPOINT IS EXCEEDED.
Other units, which do not use this special safety valve ar-
rangement, will have factory mounted safety valves on the
shell side of the oil cooler which the installing contractor
should pipe into house safety systems designated suitable
for oil relief.
The component and piping arrangement shown below is in-
tended only to illustrate the operating principles of thermosy-
phon oil cooling. Other component layouts may be better
suitedtoa specific installation.Referto publicationE70-900E
for additional information on Thermosyphon Oil Cooling.
1.Thethermosyphonoilcooleris supplied with the oil side pipedtothe compressor unit and stub ends suppliedontherefrigerantside.
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.
BC
A
OIL TEMP
CONTROL VALVE
HOT COOL
OIL OUT
HOT OIL IN
THERMOSYPHON
OIL COOLER
LIQUID
LEVEL
STATIC HEAD
TO OVERCOME
CONDENSER
PRESSURE DROP
8 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
TSOCA
Refrigerant-side drain valve
required for plate-type
thermosyphon oil coolers.

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 13
496–856 ONLY!
ECONOMIZER - HIGH STAGE (OPTIONAL)
The economizer option provides an increase in system ca-
pacityandefficiencybysubcooling liquid fromthecondenser
through a heat exchanger or flash tank before it goes to the
evaporator.The subcooling is provided by flashing liquid in
theeconomizercooler toan 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 be-
low 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 with the
economizer turned off, than it will at a low slide valve posi-
tion with the economizer turned on. Please note however
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.
Dueto thetendencyofthe portpressuretofallwith decreasing
compressor capacity, a back-pressure regulator valve (BPR)
is generally required on a flash economizer system (FIG. 3)
inordertomaintain some preset pressure differencebetween
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 ex-
ist to drive liquid from the flash vessel to the evaporators,
since the flash vessel pressure will approach suction pres-
sure at a decreased slide valve position.In cases where wide
swings in pressure are anticipated in the flash economizer
vessel, it may be necessary to add an outlet pressure regula-
tor to the flash vessel outlet to avoid overpressurizing the
economizer port, which could result in motor overload. Ex-
ample: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
preventsdirtfrom passing into the compressor and the check
valve prevents oil from flowing from the compressor unit to
the economizer vessel during shutdown.
Otherthanthe isolationvalveneeded
for strainer cleaning, it is essential
that the strainer be the last device in
the economizer line before the compressor. Also, piston-
type check valves are recommended for installation in the
economizer line, as opposed to disc-type check valves.
Thelatteraremorepronetogas-pulsation-inducedfailure.
The isolation and check valves and strainer should be lo-
cated as closely as possible to the compressor,preferably
within a few feet.
Forrefrigerationplantsemployingmultiplecompressorsonacom-
moneconomizingvessel,regardlessof economizer type, each
compressormusthaveaback-pressureregulatingvalveinorder
tobalancethe economizerload, or gasflow, betweencompres-
sors.Theproblemofbalancingloadbecomesmostimportantwhen
oneormorecompressorsrunatpartialload,exposingtheecono-
mizerporttosuctionpressure. Inthecaseofaflashvessel,there
isnoneedfortheredundancyofaback-pressureregulatingvalve
onthevesselandeachofthemultiplecompressors.OmittheBPR
valveon theflasheconomizer vesselanduse oneoneachcom-
pressor,asshowninFIG.4.Itisalsorecommendedthattheback-
pressureregulatingvalves,used oneconomizerlines,shouldbe
specifiedwithelectricshutoffoption.Theelectricshutofffeatureis
necessarytopreventflowfromthecommoneconomizervesselto
the suction side of a stopped compressor, through the suction
checkvalvebypassline,if the other compressors and the com-
moneconomizer vesselarestilloperatingand theHV2valveon
thesuction bypassisopen.
For refrigeration plants using a Packaged Refrigerant Re-
circulation (PRR) unit and a direct expansion (DX) econo-
mizer system it is necessary to operate the liquid feed sole-
noid on the PRR unit and the liquid feed solenoid on the DX
FIG. 2 - DIRECT EXPANSION ECONOMIZER SYSTEM
FIG. 1 - SHELL and COIL ECONOMIZER SYSTEM
FIG.4 -MULTIPLE COMPRESSOR ECONOMIZER SYSTEM
FIG. 3- FLASH ECONOMIZER SYSTEM
HIGH
PRESSURE
LIQUID
INTERMEDIATE PRESSURE
GAS TO COMPRESSOR
SUCTION
STR VCK
SUBCOOLED
HIGH PRESSURE
LIQUID TO
EVAPORATOR
ECONOMIZER
COOLER
ECON1
HV-2
HIGH
PRESSURE
LIQUID
INTERMEDIATE PRESSURE
GAS TO COMPRESSOR
SUCTION
STR VCK
SUBCOOLED
HIGH PRESSURE
LIQUID TO
EVAPORATOR
ECONOMIZER
COOLER
WIRING
ECON2
HV-2
HIGH
PRESSURE
LIQUID
INTERMEDIATE PRESSURE
GAS TO COMPRESSOR
SUCTION
STR VCK
CONTROLLED
PRESSURE
SATURATED LIQUID
TO EVAPORATOR
ECONOMIZER
VESSEL
BPR
ECON3
HV-2
INTERMEDIATE PRESSURE
GAS TO COMPRESSOR
SUCTION
STR VCK BPR
CONTROLLED PRESSURE
SATURATED LIQUID TO EVAPORATOR
ECONOMIZER
VESSEL
ECON4
HV-2

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION
S70-200 IOM
Page 14 496–856 ONLY!
vessel off of a common signal to avoid liquid overfeed on
the DX economizer system.
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
onaback-pressureregulator, based on percent of slide valve
travel.This will direct all the flash vapor to the other loaded
compressors.
2. Adual-setpointback-pressureregulator valvecan be used
in each of the individual economizer vapor lines. When a
compressor is running near full load, the BPR valve will op-
erateonthe desired setpoint, or basicallywideopen, to mini-
mize pressure drop in the line. When one compressor un-
loads below the slide valve position where the economizer
outputonthe microprocessor turns on, the dual-setpointfea-
ture of the regulator can be actuated by this output to con-
trol the pressure, on the vessel side of the regulator, to be a
few psi higher. Consequently, the flash gas will be sent to
the 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
helpmaintainthevesselat thedesiredpressure.An example
of a back-pressure regulator with electric shutoff and the
dual-setpoint feature is an R/S A4ADS.
ELECTRICAL
NOTE: Before beginning electrical installation,read the
instructions in the section "Proper Installation of Elec-
tronic Equipment".
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 microprocessor enclosure cover must be kept tightly
closed to prevent moisture and foreign matter from entering.
All customer connections are made
in the Quantum control panel
mounted on the unit. This is the
ONLY electrical enclosure and should be kept tightly
closed whenever work is not being done inside.
MOTOR STARTER PACKAGE
Motor starter and interlock wiring requirements are shown
inthe wiringdiagramabove.All the equipmentshown is sup-
plied by the installer unless a starter package is purchased
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. Ifspecified,the starter packagecanbesupplied as a com-
bination starter with circuit breaker disconnect. 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 circuit breaker disconnect suitable for sepa-
rate power feed.
4. A 2.0 KVA control power transformer (CPT) to supply 120
volt control power to the microprocessor control system and
separator oil heaters is included.If environmental conditions
require more than the usual two 500 watt oil heaters, an
appropriately oversized control transformer will be required.
If frequent power fluctuations are anticipated or extremely
noisypowerlinesareencountered,aregulatingcontroltrans-
formershouldbeconsidered. Contact FRICK forassistance.
5. For customer-supplied across-the-line starters, a shunt-
ing devicemust be installed across the Current Transformer
(terminals 3 & 4).
If the shunting device is not installed, the SBC board
maybe severlydamaged at start-up (see wiring diagram).
STARTERWIRING DIAGRAM
6. 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.
7. One each normally open compressor motor and oil pump
motor starter auxiliary contact should be supplied and in
addition to the compressor and oil pump motor starter coils,
the CT and CPT secondaries wired as shown on the starter
package wiring diagram. The load on the control panel for
thecompressormotor starter coilshould not exceed1Nema
size 3 starter. For larger starters, an interposing relay must
be used to switch the compressor motor starter coil(s).

RWB II ROTARY SCREW COMPRESSOR UNITS
INSTALLATION S70-200 IOM Page 15
496–856 ONLY!
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
BATTERY BACKUP
The battery backup for the QUANTUM panel is used only
for date and time retention during power interruption.All set-
points and other critical information are saved on EEPROM
chips.
The battery backup for the PLUS panel prevents data loss
during power interruption.It will maintain the adjustable set-
points stored in RAM (Random Access Memory) for up to 1
year after power loss. Expected battery life is 10 years. A
trickle charge maintains the battery backup at peak charge
when control voltage is present.
To prevent power loss, the battery backup is shipped dis-
abled. To enable the battery backup, a jumper pin located
near the top of the microprocessor circuit board (see illus-
tration in either S90-010 M (
Quantum panel) or S70-200
OM (Plus panel) must be moved from OFF (pins 1-2) to ON
(pins 2-3).
NOTE: It is not necessary to disconnect the battery
backup during extended downtime.
NOTE:The
QUANTUM microprocessor will not operate
without U24 and U35 EPROM chips installed.When U24
and U35 EPROM chips are not installed,the screen will
display:
System Board Initialized
No boot device available,
Press enter to continue.
NOTE:The PLUS microprocessor will not operate with-
out EPROM chips installed.When EPROM chips are not
installed, the microprocessor display will typically indi-
cate two dark lines across both the upper and lower dis-
play screens.
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
NOTE: Do not install a compressor HAND/OFF/AUTO
switch in the starter package as this would bypass the
compressor safety devices.
CONTROL POWER REGULATOR
Compressorunitsthatwillbeusedinareasthatsufferbrown-
outs and other significant power fluctuations can be sup-
plied with a control power regulator. See the following illus-
tration, Recommended Regulator Installation.
RECOMMENDED REGULATOR INSTALLATION

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 16 496–856 ONLY!
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 OM & 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
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
OPERATETHE 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-
sure and low pressure applications. The compressor
incorporates 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 com-
pressor.
3. Balance pistons located in the inlet end of the compres-
sor to reduce axial loads on the axial load bearings and
increase bearing life.
4. Moveable slide valve to provide infinite step capacity con-
trol from 100 to 10%.
5. VOLUMIZER® volume ratio control to allow infinitely vari-
able volume ratio from 2.2 to 5.0 during compressor opera-
tion 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 and casing design for 350 PSI discharge pres-
sure.This PSI rating applies only to the compressor and
does not reflect the design pressure of the various sys-
tem 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. Oilinjected into the rotors tomaintain good volumetric 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-
VERSEROTATION AS BEARING DAMAGEWILL RESULT.
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 pre-
lube, full-lube or cycling full-lube lubrication system. Addi-
tionally, either system may contain dual oil filters and liquid
injection, water-cooled, or thermosyphon oil cooler for com-
pressor oil cooling.
PRELUBE OIL SYSTEM
The RWB II screw compressor unit is designed to be
self-lubricating. Oil being supplied to the compressor from
the oil separator is at system head pressure. Within the
compressor, oil porting to all parts of the compressor is
vented back to a point in the compressor’s body that is at a
pressure lower than compressor discharge pressure. The
compressor’s normal operation makes the compressor unit
operate essentially as its own oil pump. All oil entering the
compressoris moved by thecompressor rotors out thecom-
pressor outlet and back to the oil separator.
For normal operation an oil pump is not required except to
lubricate the compressor during start-up.During the period
from start-up to normal operation, the oil pressure alarm
and oil pressure cutout setpoints will vary according to for-
mulas built into the microprocessor control program. On
start-up the PRELUBE pump has 30 seconds to produce
over five pounds of oil pressure over registered discharge
pressure or a cutout will occur.When the compressor starts,
oil pressure will be ignored for two minutes. After 25 PSID

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION S70-200 IOM Page 17
496–856 ONLY!
COMPRESSOR OIL SEPARATION SYSTEM
The RWB II is an oil flooded screw compressor. Most of the
oil discharged by the compressor separates from the gas
flow in the oil charge reservoir. Some oil, however, is dis-
charged 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, the droplets of oil fall to the bottom of the coa-
lescer section of the oil separator. The return of this oil to
the compressor is controlled by a needle valve on both high
stage and booster applications.
NOTE: Open needle valve only enough to keep
coalescer end of separator free of oil.
The sight glass located near the bottom of the coalescer
section 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
compressoroperationhasdeveloped.Referto Maintenance
for information on how to correct the problem.
OIL SEPARATION SYSTEMS
HORIZONTAL, MODELS 60 - 856 VERTICAL, MODELS 496 - 856
COMPRESSOR MOTOR
OF-1
OF-3
3ELEMENT
MAIN OIL INJECTION
SINGLE ELEMENT
BEARING FEED
OILSEPR2
COMPRESSOR MOTOR
SEPARATOR
OIL CHARGE
TO OIL
PUMP
FROM OIL
PUMP
OF-1
COALESCENT
FILTER
OILSEPR
pressure differential has been reached between suction
and discharge, the PRELUBE pump will shut down and the
lubrication oil will be supplied by the pressure differential. If
after five minutes 25 PSID has not been reached, the unit
will shutdown on DCO cutout.
NOTE: For alarm descriptions and shutdown or cutout
parameters, see S90-010 OM (Quantum) or S70-200 OM
(Plus).
CYCLING FULL-LUBE OIL SYSTEM
This system is designed to provide those high stage appli-
cations that operate with normal to low differential pressure
acrossthe compressor suction and dischargewith adequate
compressor lubrication.
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. On start-up the oil pump has 30 seconds to pro-
duce over five pounds of oil pressure above registered dis-
charge pressure or a cutout will occur.
During the start-up
sequencemodels496–856only,thesolenoidvalvein the
main injection feed is closed to allow oil to feed into the
slide valve and bearing ports only.
After the compressor
starts and the pressure is between 5 PSI and 10 PSI differen-
tial, the prealarm signal is activated. If the oil pressure is
above 10 PSI, the alarm can be cleared.The pump will con-
tinue to run until the discharge pressure is 55 PSI over suc-
tion pressure, then it will shut down. When the pressure dif-
ferential falls below 45 PSI, the pump will start again.
NOTE: For alarm and shutdown or cutout values, see
S90-010 OM (Quantum) or S70-200 OM (Plus).
FULL-LUBE OIL SYSTEM
RWB II booster compressors and high stage compressors
that operate with very low differential pressures across the
compressor suction and compressor discharge require a
full time oil pump to produce the oil flow and pressures re-
quired. Oil is pumped from the oil separator through the oil
filter to the main oil injection feed and the compressor. An
oil pressure regulating valve downstream of the pump is
used to regulate oil pressure at the compressor by return-
ing excess oil to the separator.
During the start-up se-
quence of the models 496 – 856 only,the solenoid valve
in the main oil injection feed is closed to allow oil to
feed into the slide valve and bearing ports only.
Oil pressure on RWB II compressors with full time oil pumps
should be adjusted to provide 20 - 25 PSI (high stage) or 30
- 35 PSI (booster) pounds of oil pressure at the highest nor-
mal head pressure or intermediate pressure expected with
the compressor fully loaded. The compressor will require
maximum oil flow under these conditions.

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 18 496–856 ONLY!
COMPRESSOR HYDRAULIC SYSTEM
The compressor hydraulic system moves the movable slide
valve(MSV) to loadandunloadthecompressor.It also moves
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 the right.Bothsections are considered double
acting hydraulic cylinders as oil pressure moves the pistons
in either direction.
Both sections are controlled by double-acting, four-way so-
lenoid valves which are actuated when a signal from the
appropriate microprocessor output energizes the solenoid
valve.
Compressor Loading: The compressor loads when MSV
solenoid YY2 is energized and oil flows from the oil mani-
fold through valve ports P and B to cylinder port SC-2 and
enters the load side of the cylinder.Simultaneously, oil con-
tained in the unload side of the cylinder flows out cylinder
port SC-1 through valve ports A andT 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-
pressorportSC-2throughvalveportsBandT to compressor
closed thread port.
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 in-
creased by closing valve 1 (oil manifold pressure) and open-
ing valve 2 to compressor suction pressure. See illustra-
tions.NEVER OPENVALVE 1
AND VALVE 2 ATTHE SAME
TIME DURING COMPRESSOR OPERATION.
VOLUMIZER® VOLUME RATIO CONTROL
Vi Increase
Models 60 through 270: The volume ratio Vi is increased
when MSS solenoidYY3 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. Simul-
taneously, 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.
Models 316 through 856:
The volume ratioVi is increased
when the MSS solenoid valve YY3 is energized and oil
flows from oil manifold through valve ports P and A to com-
pressor port SC-3, enters the increase side of the cylinder
and overcomes the decrease spring tension.
Vi Decrease
Models 60 through 270: The volume ratio Vi is decreased
when MSS solenoidYY4 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. Simul-
taneously, 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.
Models 316 through 856:
The volume ratioVi is decreased
when the MSS solenoid valve YY4 is energized and oil
flows from the cylinder through compressor port SC-3,
through valve ports A and T, to compressor Port SC-4.

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION S70-200 IOM Page 19
496–856 ONLY!
VALVE 2
SUCTION
COMPRESSOR
SC-8
VALVE 1
YY2 YY1 YY3YY4
HIGH STAGE
BOOSTER
CLOSE VALVE 1
OPEN VALVE 2
CLOSE VALVE 2
OPEN VALVE 1
ABA B
BP
TAP
T
BA
SC-1SC-2
SC-3
SC-4
FROM FRICK
OIL FILTER
SOLENOID VALVE FUNCTION: YY1 ENERGIZE UNLOAD SLIDE VALVE
YY2 ENERGIZE LOAD SLIDEVALVE
YY3 ENERGIZE INCREASEVOLUME RATIO
YY4 ENERGIZE DECREASEVOLUME RATIO SOLVALVE

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 20 496–856 ONLY!
COMPRESSOR OIL COOLING SYSTEMS
The RWB II unit can be equipped with one of several sys-
tems for controlling the compressor oil temperature. They
are single or dual-port liquid injection, or thermosyphon and
water-cooled oil coolers. Each system is automatically con-
trolled, 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 - 150°F 120 - 140°F
*Thermosyphon oilcooling(TSOC) orWater-cooledoil cool-
ing (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.
SolenoidvalveSV5isenergizedbythe microprocessor when
thetemperaturesensor,installed in theoil manifold,exceeds
the LICO set point. High pressure liquid refrigerant is then
supplied to the temperature control valve (TCV). The tem-
perature control valve is equalized to a constant back pres-
sure 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 compres-
sor 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
providing the temperature control valve (TCV) with a con-
stant back pressure.
A solenoid valve SV6 is installed before the differential pres-
sure control valve (PDCV) to prevent migration of high pres-
sure gas during shutdown. A Frick-installed timer limits the
high pressure gas to only thirty seconds duration, since in-
termediate gas pressure and spring tension are sufficient 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
between the high stage compressor discharge piping 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
compression ratios by permitting injection of liquid refriger-
antintooneoftwoports 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 sole-
noid valve SV7 and operates as outlined.
SolenoidvalveSV5isenergizedbythe microprocessor when
thetemperaturesensor,installed in theoil manifold,exceeds
the LICO set point.Liquid refrigerant is then passed through
the temperature control valve (TCV) to the double-acting
solenoid valve SV7. Depending on the compressor’s oper-
ating 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.
The temperature control valve is equalized to a constant
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.Thegasdownstreamof both
valvesis bledoff to the compressor suctionto ensure steady
and constant operation of the valves.
LIQUID INJECTION ADJUSTMENT
PROCEDURE
1. Close back-pressure bleed valve (V4).
2. Set pressure regulator valve (PDCV) for approximately
100 to 110 psig.
3. Open back-pressure bleed valve (V4) approximately one
quarter turn.
4. Monitor the oil temperature of the compressor. It the oil
temperature rises above 150°F, open back-pressure bleed
valve (V4) a very small amount. This will reduce pressure
on the equalizer and allow more refrigerant to flow to the
compressor.If the oil temperature drops below 130°F, close
back-pressure bleed valve (V4) a very small amount. This
will increase pressure on the equalizer and allow less re-
frigerant to flow to the compressor, thus raising the oil tem-
perature.The ideal condition is to maintain an oil tempera-
ture as stable as possible. By keeping the liquid injection
systemcorrectlytuned,extremeswingsin the discharge tem-
perature and the oil temperature can be avoided.
Back-pressure bleed valve (V4)
must always be cracked open a
small amount to prevent refrigerant
from condensing in the tubing.