mycom 3225**C Series User manual

2202MYJE-MY-C8-N_2018.02.
Compound 2-stage Screw Compressor
3225 * * CInstruction Manual
3225LLLC/3225LLMC/3225LLSC/3225LLC/3225LMC/3225LSC
3225MLC/3225MMC/3225MSC/3225SLC/3225SMC/3225SSC
CAUTION
Before operating, servicing, or inspecting this product, read this manual thoroughly to fully
understand the contents.
Keep this Instruction Manual in a safe, designated place for future reference whenever the
manual is needed.
Specifications of this product and contents of this manual are subject to change without
prior notice due to technical improvements, and the like.

2202MYJE-MY-C8-N_2018.02.
Preface
Compound 2-stage Screw Compressor 3225**C i
Preface
Thank you for purchasing the C-series compound 2-stage screw compressor 3225**C
(hereinafter referred to as "this product").
This Instruction Manual (hereinafter referred to as "this manual") provides safety information and
operation and maintenance procedures, so that users correctly understand how to handle this product
and, as a result, can use it safely and efficiently. This manual is applicable to the following models:
3225LLLC-*B*-51
3225LLLC-*B*-61
3225LLMC-*B*-51
3225LLMC-*B*-61
3225LLSC-*B*-51
3225LLSC-*B*-61
3225LLC-*B*-51
3225LLC-*B*-61
3225LMC-*B*-51
3225LMC-*B*-61
3225LSC-*B*-51
3225LSC-*B*-61
3225MLC-*B*-51
3225MLC-*B*-61
3225MMC-*B*-51
3225MMC-*B*-61
3225MSC-*B*-51
3225MSC-*B*-61
3225SLC-*B*-51
3225SLC-*B*-61
3225SMC-*B*-51
3225SMC-*B*-61
3225SSC-*B*-51
3225SSC-*B*-61
* -51 (-61) may not be written. For more information, see 2.2 "Model designation of the compressor"
in this manual Chapter 2.
Make sure you read this manual before installing or using this product.
Keep this manual in a safe place near this product for quick reference.
Revision History
Title
Document No.
First edition issue date
3225**C Instruction Manual
2202MYJE-MY-C8-N_2018.02.
Nov. 14, 2014
Revision
No.
Issue date
Major Contents of revisions
Created/approved by:
00
Nov. 14, 2014
Overall review associated with reissue as
electronic document, document No. change
Ikehara / Hirao
01
Apr. 30, 2015
Modified the constitution of Chapter 4 and
Chapter 5. Correction of describing, etc.
Ikehara / Muta
02
Feb.28.2018
Corrected Table 2-1&2-2, Figure 2-1～12, Table
7-1&7-2. Corrected other errors. Deleted
Contact Information
Takenouchi・Ito/Kato

2202MYJE-MY-C8-N_2018.02.
Warranty and Disclaimer
Compound 2-stage Screw Compressor 3225**C ii
Warranty and Disclaimer
Warranty
MAYEKAWA shall repair or replace parts of this product for no charge if any failure resulting from
defects in design or manufacture occurs, under normal use with the purpose and method that are in
accordance with the specifications of this product and this manual, within the warranty period.
The warranty period is "12 months from factory shipment of this product". If there is a separate
agreement, that agreement shall prevail in principle.
MAYEKAWA is not liable for production or man-made disaster compensation due to malfunction or
damage of this product.
Disclaimer of Warranty
Although MAYEKAWA warrants the clauses mentioned above, the following clauses are exempted.
Malfunction or damage of this product caused by natural disaster, or other accidental forces
(such as fire, thunderbolt, windstorm, intense rainfall, flood, tidal wave, earthquake, land
subsidence, etc.).
Malfunction or damage caused by misusage described below.
Malfunctions, damage, or deterioration of this product due to abnormal or improper use
(including improperly storing this product outdoors or under too hot/humid conditions,
unexpected inspections, tests, operations, too frequent liquid flow-back operation*, and
too frequent start-stop cycles, etc.).
Malfunction or damage caused by devices or equipments not provided by MAYEKAWA
including operation control methods of those devices.
Malfunction or damage caused by refrigerants, gases, or refrigerant oils, and operating
conditions (design conditions) not approved for this product.
Malfunction or damage caused by maintenance or inspection not recommended by
MAYEKAWA.
Malfunction or damage caused by parts that are not genuine.
Malfunction or damage caused by remodeling the product without approval of
MAYEKAWA.
Malfunction or damage caused by unexpected misusage
"Liquid flow-back operation" is ･･･
Normally, while the compressor sucks in the refrigerant liquid only after vaporizing it in the
evaporator, it may directly sucks it in because of the faulty adjustment or failure of the
expansion valve. We call this state of compressor operation "liquid flow-back operation".
No compressor can compress a liquid. The compressor may be damaged should the liquid be
sucked in.

2202MYJE-MY-C8-N_2018.02.
Important Information
Compound 2-stage Screw Compressor 3225**C iii
Important Information
Intended Use of This Product
This product is a general-purpose screw compressor for refrigeration, cold storage and various gases
compression. Do not use this product for any other purposes that are not intended for or which depart
from the specifications. For specifications of this product, refer to "2.3 Compressor Specifications".
Please perform the maintenance items described in this manual by using safe and assured procedures.
For Safe Use of This Product
Although MAYEKAWA has paid a lot of attention to safety measures for this product, all hazards
including potential hazards caused by human errors, or due to environmental conditions can not be
anticipated.
As there are too many items to be strictly observed or prohibited when using this product, it is
impossible to inform all of them through this manual. Therefore, when operating this product, pay
extreme caution on personnel safety as well as on items described in this manual.
Important rules for safety work with this product that apply to all workers including managers and
supervisors are listed below.
Please read this manual before using this product. Fully understand the instructions provided there,
and be sure to perform the safety procedures described in this manual.
Operation, maintenance, and inspection of this product should be performed by qualified
personnel educated about the fundamentals of this product and trained about hazards
involved and measures to avoid danger.
Do not allow any person other than those educated on the fundamental expertise of this
product and trained about hazards involved and measures to avoid dangers to approach this
product while it is operating or during maintenance.
Observe all related federal/national and local codes and regulations.
To prevent accidents, do not carry out any operation or maintenance other than those
described in this manual. Do not use this product for any purpose other than intended.
Replace the parts with genuine parts.
Not only workers but also managers should actively participate safety and health activities in
the workplace to prevent accidents.
When closing or opening a valve during work, make sure to apply lockout/tagout to prevent
the valve from being accidentally closed or opened during the work.
[Lockout] To lock with a key in order to keep people, except the workers involved, from
operating the product.
Lockout means disconnecting or keeping disconnected machines and devices by locking their energy
(power) sources. Lockout is not just simply turning off the power switches to stop the supply of power,
but includes immobilizing them with a key or similar device to keep any blocked switches from being
operated.
Lockout devices are devices such as keys, covers, and latches, to immobilize switches, valves,
opening and closing levers, etc., with a state of being locked.
[Tagout] To prevent any inappropriate work by hanging tag plates indicating "work in progress".
Tagout means to clearly indicate, by hanging tag plates, that a device is in lockout and that operation of
the device is prohibited. Tag plates forbidding operation, starting, opening, etc. are warnings clearly
stating to not operate energy (power) sources, and are not for stopping blocking devices.

2202MYJE-MY-C8-N_2018.02.
Important Information
Compound 2-stage Screw Compressor 3225**C iv
Observe the following precautions when performing maintenance work on electrical control.
Electrical maintenance of the product must be performed by certified/qualified personnel and
only those educated about the electrical control of the product.
Before servicing or inspecting the electrical equipment or devices, turn "OFF" the motor main
power and control power, and perform lockout/tagout to prevent the power from being turned
on during work.
Even when the motor main power and control power are turned "OFF", this product may be turned on if
the power is supplied from outside the package unit. Make sure the power supply on the power source
side is shut off, and perform lockout/tagout to prevent the product from being turned on during work.
About This Manual
This product may be modified without prior notice. Therefore, the appearance of actual
machine may differ from the descriptions in this manual. If you have any questions, contact
our sales offices or service centers. For each sight of MAYEKAWA, refer to following URL.
http://www.mayekawa.com/about/network/
This manual is in English. If any other language is required, it is the customers’responsibility
to prepare a manual for safety education and operation instructions.
This manual is copyrighted. Drawings and technical references including this manual shall not,
in whole or part, be copied, photocopied, or reproduced into any electronic medium or
machine-readable form without prior permission from MAYEKAWA.
Photographs or drawings included in this manual may differ from the appearance of actual
product.
If this manual is lost or damaged, immediately request our local sales offices or service
centers for a new manual. Using this product without the manual may result in safety issues.
If you resell this product, never fail to attach this manual to this product.
Construction of This Manual
Title of section and chapter
Description details
Preface
Describes the outline of this manual and how to read this manual.
Warranty and Disclaimer
Describes what MAYEKAWA warrants and what are covered by
the warranties. Warranty exemption is stated as disclaimer.
Important Information
Describes important information related to this product and this
manual.
1. Safety
Describes safety information for the worker, safety rules for this
product, and management details regarding the work safety that
is required for handling this product.
2. Compressor Specifications and
Structure
Describes the main components of this product, functional
information, specification, and operating limits.
3. Installation
Describes the installation procedure of this product.
4. Compressor and Package Unit
Operation
Describes the precautions for operating this product.
5. Maintenance and Inspection
Describes sections and period for inspecting, and assembly and
disassembly of this product.
6. Troubleshooting
Describes troubleshooting methods for this product in case
problems occur during operation of this product.
7. Related Documents
Describes documents such as exploded views and parts list.

2202MYJE-MY-C8-N_2018.02.
Table of Contents
Compound 2-stage Screw Compressor 3225**C v
Table of Contents
Preface .................................................................................................................... ⅰ
Revision History..................................................................................................... ⅰ
Warranty and Disclaimer....................................................................................... ⅱ
Important Information............................................................................................ ⅲ
Intended Use of This Product ...........................................................................................ⅲ
Important Information for Safe Use of This Product ..........................................................ⅲ
About This Manual.............................................................................................................ⅳ
Construction of This Manual..............................................................................................ⅳ
Table of Contents................................................................................................... ⅴ
Chapter 1 Safety
1.1 Strict Requirements and Prohibitions........................................................1-1
1.1.1 Strict Requirements (Do’s)...................................................................................1-1
1.1.1.1 Do’s on Operation........................................................................................1-1
1.1.1.2 Do’s on Maintenance...................................................................................1-1
1.1.1.3 Do’s on Lockout/Tagout after Shutting Off the Power .................................1-1
1.1.1.4 Do’s about Personal Protective Gear..........................................................1-2
1.1.1.5 Do’s about Handling of Hazardous and Toxic Substances.......................... 1-2
1.1.1.6 Do’s about Handling Emergency Situations................................................1-2
1.1.1.7 Do’s about Waste Oil, Fluid, and Materials ................................................. 1-2
1.1.1.8 Other Do’s....................................................................................................1-3
1.1.2 Prohibitions (Don’ts).........................................................................................1-3
1.2 Warnings.......................................................................................................1-3
1.3 Residual Risks .............................................................................................1-4
1.4 Safety Devices..............................................................................................1-6
1.4.1 Emergency Stop Button....................................................................................... 1-6
1.4.2 Breakers of motor main power and control power
(with Lockout/Tagout Mechanism) ......................................................................1-6
1.4.3 Compressor Protective Devices.......................................................................... 1-7
Chapter 2 Compressor Specifications and Structure
2.1 Overview of the 3225**C .............................................................2-1
2.2 Model Designation of the Compressor ...................................................2-1
2.3 Compressor Specifications ........................................................................2-2
2.3.1 Standard Specifications.......................................................................................2-2
2.3.2 Operation Limits................................................................................................... 2-4
2.3.3 Outer Dimensions................................................................................................ 2-5
2.4 Structure of Compressor ..........................................................................2-17
2.4.1 Sectional View...................................................................................................2-17

2202MYJE-MY-C8-N_2018.02.
Table of Contents
Compound 2-stage Screw Compressor 3225**C vi
2.5 Mechanisms ...............................................................................................2-18
2.5.1 Basics of the Screw Compressor ......................................................................2-18
2.5.2 Suction Process.................................................................................................2-18
2.5.3 Compression Process........................................................................................2-19
2.5.4 Discharge Process............................................................................................. 2-19
2.5.5 About Volume Ratio (Vi).................................................................................... 2-19
2.5.6 Capacity Control Mechanism.............................................................................2-21
2.5.7 Bearings and Balance Piston ............................................................................ 2-21
2.5.8 Shaft Seal Block ................................................................................................ 2-21
2.6 Gas and Oil Flow........................................................................................2-22
Chapter 3 Installation
3.1 General Precautions for Installation ..........................................................3-1
3.2 Installation Works........................................................................................3-1
3.2.1 Unpacking............................................................................................................3-1
3.2.2 Storage ................................................................................................................3-1
3.2.3 Transportation......................................................................................................3-1
3.2.4 Preparation for Installation................................................................................... 3-4
3.2.5 Installation............................................................................................................3-5
3.2.5.1 Installation....................................................................................................3-5
3.2.5.2 Shaft Alignment between the Compressor and Driving Machine................3-5
3.2.5.3 Piping Connection .......................................................................................3-6
3.2.5.4 Equipment and Devices for Protection of the Compressor.........................3-6
3.2.6 Airtightness Test.................................................................................................. 3-7
3.2.7 Lubricating Oil Charge.........................................................................................3-7
3.2.7.1 Initial Charge of Lubricating Oil................................................................... 3-7
3.2.7.2 Additional Charge of Lubricating Oil............................................................ 3-7
3.2.8 Charge of Refrigerant..........................................................................................3-7
3.2.9 Check after Installation........................................................................................ 3-7
Chapter 4 Compressor and Package Unit Operation
4.1 Lubricating Oil (Refrigerant Oil) .................................................................4-1
4.1.1 Precautions for Selecting the Lubricating Oil.......................................................4-1
4.1.2 Recommended Lubricating Oils .......................................................................... 4-1
4.1.2.1 Recommended Lubricating Oils for Ammonia Refrigerant..........................4-1
4.1.2.2 Oils for systems using Hydrofluorocarbon refrigerants............................... 4-2
4.1.3 Change of Lubricating Oil Brand ......................................................................... 4-3
4.1.4 Precautions for Handling lubricating Oil.............................................................. 4-4
4.1.5 Lubricating Oil Management Criteria................................................................... 4-5
4.1.6 Lubricating Oil Replacement Timing.................................................................... 4-6
4.1.6.1 After Starting the Initial Operation ...............................................................4-6
4.1.6.2 During Normal Operation.............................................................................4-6

2202MYJE-MY-C8-N_2018.02.
Table of Contents
Compound 2-stage Screw Compressor 3225**C vii
4.2 Precautions for Operation...........................................................................4-7
4.2.1 Prevention of Liquid Flow-back Operation........................................................... 4-7
4.2.2 Purging of Non-Condensable Gases................................................................... 4-7
4.3 When Stopping the Compressor for a Long Time ....................................4-8
Chapter 5 Maintenance and Inspection
5.1 Precautions for Maintenance and Inspection............................................5-1
5.2 Maintenance and Inspection List................................................................5-3
5.2.1 Daily Management...............................................................................................5-3
5.2.2 Periodic Inspection .............................................................................................. 5-5
5.2.3 Guidelines for the Timing of Compressor Overhaul............................................ 5-6
5.3 Compressor Disassembly Preparation......................................................5-7
5.3.1 Disassembly Tools and Workplace .....................................................................5-7
5.3.2 Replacement Parts..............................................................................................5-8
5.3.3 Refrigerant Gas Recovery................................................................................. 5-11
5.3.4 Removal of Connections to the Unit..................................................................5-12
5.3.5 Removal and Lifting the Compressor................................................................5-13
5.3.6 Draining Oil from the Compressor..................................................................... 5-13
5.4 Disassembly and Inspection.....................................................................5-14
5.4.1 Unloader Indicator ............................................................................................. 5-15
5.4.1.1 Disassembly..............................................................................................5-15
5.4.1.2 Inspection..................................................................................................5-17
5.4.2 Unloader Cover.................................................................................................. 5-18
5.4.2.1 Disassembly..............................................................................................5-18
5.4.2.2 Inspection..................................................................................................5-19
5.4.3 Unloader Piston and Unloader Cylinder............................................................5-20
5.4.3.1 Disassembly..............................................................................................5-20
5.4.3.2 Inspection.................................................................................................. 5-21
5.4.4 Shaft Seal Block ................................................................................................5-22
5.4.4.1 Disassembly..............................................................................................5-22
5.4.4.2 Inspection..................................................................................................5-23
5.4.5 Bearing Cover.................................................................................................... 5-24
5.4.5.1 Disassembly..............................................................................................5-24
5.4.6 Separating High-stage and Low-stage Blocks...................................................5-25
5.4.6.1 Disassembly..............................................................................................5-25
5.4.7 Gear Coupling....................................................................................................5-25
5.4.7.1 Disassembly..............................................................................................5-25
5.4.7.2 Inspection..................................................................................................5-26
5.4.8 Removing Oil Injection Pipe...............................................................................5-27
5.4.8.1 Disassembly...............................................................................................5-27
5.4.9 Balance Piston................................................................................................... 5-28
5.4.9.1 Disassembly..............................................................................................5-28
5.4.9.2 Inspection..................................................................................................5-28
5.4.10 High-stage Suction Cover and Side Bearings................................................... 5-29

2202MYJE-MY-C8-N_2018.02.
Table of Contents
Compound 2-stage Screw Compressor 3225**C viii
5.4.10.1 Disassembly..............................................................................................5-29
5.4.10.2 Inspection.................................................................................................. 5-30
5.4.11 Low-stage Suction Cover and Side Bearings....................................................5-31
5.4.11.1 Disassembly..............................................................................................5-31
5.4.11.2 Inspection.................................................................................................. 5-31
5.4.12 Thrust Bearing Block .........................................................................................5-32
5.4.12.1 Disassembly of the High-stage Thrust Bearing Block...............................5-32
5.4.12.2 Disassembly of the Low-stage Thrust Bearing Block................................5-33
5.4.12.3 Inspection (High-stage and Low-stage).....................................................5-33
5.4.13 High-stage Rotors and Main Rotor Casing........................................................5-34
5.4.13.1 Disassembly..............................................................................................5-34
5.4.13.2 Inspection.................................................................................................. 5-35
5.4.14 Low-stage Rotors and Main Rotor Casing......................................................... 5-35
5.4.15 High-stage Bearing Head and Main Bearings...................................................5-36
5.4.15.1 Disassembly..............................................................................................5-36
5.4.15.2 Inspection.................................................................................................. 5-36
5.4.16 Low-stage Bearing Head and Main Bearings....................................................5-37
5.4.16.1 Disassembly..............................................................................................5-37
5.4.16.2 Inspection.................................................................................................. 5-37
5.5 Reassembly................................................................................................5-38
5.5.1 Unloader Slide Valve and Guide Block..............................................................5-40
5.5.2 Bearing Head and Main Bearings......................................................................5-41
5.5.3 Bearing Head and Main Rotor Casing............................................................... 5-42
5.5.4 Installing the Rotors........................................................................................... 5-43
5.5.5 Suction Cover and Side Bearings......................................................................5-44
5.5.6 Balance Piston Sleeve....................................................................................... 5-45
5.5.7 Installing the Suction Cover............................................................................... 5-46
5.5.8 Thrust Bearing Block .........................................................................................5-48
5.5.8.1 End Clearance Measurement....................................................................5-50
5.5.8.2 End Clearance Adjustment Procedure......................................................5-51
5.5.8.3 Tightening after Finishing the End ClearanceAdjustment ........................5-52
5.5.8.4 Installing the Balance Piston..................................................................... 5-53
5.5.9 Balance Piston Cover and High-stage Unloader Cylinder.................................5-53
5.5.10 Bearing Cover.................................................................................................... 5-56
5.5.11 Shaft Seal Block ................................................................................................ 5-57
5.5.12 Low-stage Unloader Cylinder............................................................................5-60
5.5.13 Unloader Cover..................................................................................................5-61
5.5.14 Coupling the High-stage and Low-stage Blocks................................................5-62
5.5.15 Unloader Indicator ............................................................................................. 5-64
5.5.15.1 Potentiometer............................................................................................5-64
5.5.15.2 Micro-switches and Micro-switch Cam......................................................5-64
5.5.15.3 Reassembly............................................................................................... 5-65

2202MYJE-MY-C8-N_2018.02.
Table of Contents
Compound 2-stage Screw Compressor 3225**C ix
Chapter 6 Troubleshooting
01: Compressor does not start up............................................................................ 6-1
02: Compressor stops immediately after startup ................................................... 6-1
03: Unusually low pressure (decrease of suction pressure)................................. 6-2
04: Low oil pressure (low lubricating oil supply pressure) ................................... 6-2
05: Intermediate pressure is unusually high........................................................... 6-3
06: Unusually high pressure (abnormal discharge pressure)............................... 6-4
07: Discharge temperature is abnormally high....................................................... 6-5
08: Leak from mechanical seal ................................................................................. 6-6
09: Squeaking of mechanical seal............................................................................ 6-7
10: Capacity control position is indicated incorrectly ........................................... 6-7
11: Capacity control malfunction.............................................................................. 6-8
12: Compressor generates abnormal vibration and/or sound .............................. 6-9
Chapter 7 Related Documents
7.1 Exploded Views, Assembly Sectional Views ............................................7-1
7.2 Parts Configuration Table.........................................................................7-27
7.3 Tightening Torques for Bolts and Nuts...................................................7-34
7.4 About the O-rings Used.............................................................................7-36
7.4.1 List of O-rings Used........................................................................................... 7-36
7.4.2 O-ring Materials Used for Screw Compressor................................................... 7-36
7.5 Tools for Disassembly...............................................................................7-37

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.1 Strict Requirements and Prohibitions
1-1
Chapter 1 Safety
1.1 Strict Requirements and Prohibitions
1.1.1 Strict Requirements (Do’s)
1.1.1.1 Do’s on Operation
Make sure to install safety and protective devices on the package unit.
Regularly inspect the safety and protective devices if they function properly.
If the safety or protective devices do not work properly or if this product operates abnormally,
immediately stop the operation and report to the supervisor. Obtain his/her approval and
direction before restarting the compressor.
If this product stops for unknown reasons, immediately inform your supervisor of it. Obtain
his/her approval before restarting the compressor.
Some types of refrigerants emit bad smell or toxic gases when they leak. Make sure to
ventilate the air during operation.
For the properties of refrigerant and lubricating oil (corrosiveness, decomposability or toxicity),
be sure to obtain the Safety Data Sheet (SDS) and follow the relevant information.
When stopping the operation of this product, close the suction and discharge side shut-off
valves and turn "OFF" the motor (main power), heater power, and control power.
1.1.1.2 Do’s on Maintenance
Prepare work procedures based on a work schedule. Be sure to perform danger forecasting
before starting the work.
Before performing the work together with at least one other person, thoroughly confirm each
other's work details and procedures to acknowledge the other worker's movement.
When troubleshooting during operation or before performing setup, cleaning, maintenance,
or inspection of this product, always turn OFF the main power to the motor and control power
and other devices. Also, lock and tag out them to prevent the power from being supplied
erroneously during operation.
When troubleshooting during operation or before performing setup, cleaning, maintenance,
or inspection of this product, confirm that the pressure inside this product and the package unit
is at atmospheric pressure.
Some refrigerants in use generate bad smell or toxic gases, or may cause deficiency of
oxygen. Before starting work, measure oxygen concentration in the work area as necessary.
Ventilate the area well. Be sure to keep the area well ventilated until the work is finished.
For the properties of refrigerant and lubricating oil (corrosiveness, decomposability or toxicity),
be sure to obtain the Safety Data Sheet (SDS) and follow the relevant information.
After using tools always restore to designated place and never leave tools in the package unit
1.1.1.3 Do’s on Lockout/Tagout after Shutting Off the Power
Attach lockout/tagout mechanism to the main breakers of motor main power and control power.
Lockout/tagout after power off is a very effective means to secure safety. It can prevent the
power source from being turned on by accident by two or more workers which may cause
injury to other worker(s).

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.1 Strict Requirements and Prohibitions
1-2
If there are any possibilities of danger during works (especially during cleaning, maintenance
and inspection, and troubleshooting), turn "OFF" the motor main power and control power, and
perform lockout/tagout.
In the following situations, workers may neglect to perform power source shutoff or
lockout/tagout. Clearly notify the workers of the necessity of lockout/tagout.
It is assumed that workers do not perform lockout/tagout before starting work because it is
troublesome, and only turn "OFF" the main motor and control power.
It is assumed that workers only turn off the main motor and control power and do not
lockout/tagout the main motor and control power, because they judge that there is no
danger.
1.1.1.4 Do’s about Personal Protective Gear
Prepare and use protective gear complying with the safety standards of the regulations.
Check the function of each protective gear before using.
Wear designated clothes such as work outfits, with their cuffs tightly closed.
Do not wear any neckties or jewelry as there is a risk of being entangled by a movable part or
rotating part. Put on a helmet as your hair may get entangled.
Do not have anything in your pocket to prevent objects from falling into the machine.
1.1.1.5 Do’s about Handling of Hazardous and Toxic Substances
Obtain the Safety Data Sheet (SDS) from manufacturers of hazardous and toxic substances.
Check the SDS and follow the handling instructions recommended by the manufacturers to
handle and store those substances.
1.1.1.6 Do’s about Handling Emergency Situations
Formulate an emergency action plan complying with the regulations, and post it on a safe
place.
1.1.1.7 Do’s about Waste Oil, Fluid, and Materials
Disposing of refrigerant and oil used for this product are subject to a number of regulations for
the environmental protection purposes. Follow the local, state, federal acts and regulations
and your company's rules when disposing of such waste oil, fluid and materials.
1.1.1.8 Other Do’s
Clean the floor around the entire refrigerating/cold storage/gas compression package unit.
Provide a safety passage.
Walk only on the areas set up as a work floor. Also, do not leave tools and cleaning solutions
in that area.
If water or oil is spilled on this product or the floor, immediately wipe it off to prevent workers
from slipping and getting injured.

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.2 Warnings
1-3
1.1.2 Prohibitions (Don’ts)
Do not remove or relocate any safety device, including electrical interfaces.
Do not disable any safety device by short-circuiting or bypassing without any permission.
Do not leave this product unsafe and unattended, by removing a safety cover or some other
measures.
Do not touch, clean or lubricate any part of this product which is moving.
Do not touch relays or electric systems such as terminal block with bare hands when turning
on the power.
1.2 Warnings
The warning messages described in this manual warn dangerous situations that may arise during work
by using the following four categories.
Neglecting such warnings may cause accidents, resulting in personal injury or even death.
Also, this product or its auxiliary equipment may be heavily damaged. Therefore, be sure to always
observe the instructions of the warnings.
Table 1-1 Warning Symbols and their Meanings
Symbol
Meaning
Indicates a hazardous situation which, if not avoided, could very likely cause
serious injury or death.
Indicates a potentially hazardous situation which, if not avoided, may cause serious
injury or death.
Indicates a potentially hazardous situation which, if not avoided, may cause minor
or moderate injury.
Indicates a potentially hazardous situation which, if not avoided, may result in
property damage.

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.3 Residual Risks
1-4
1.3 Residual Risks
The following information assumes that this product is operated or inspected/maintained while being
used in general refrigerating/cold storage/gas compression package units.
Note that all hazardous sources cannot be predicted for the applications mentioned.
Devise appropriate countermeasures for hazardous sources in your systems.
Table 1-2 Hazardous Sources
Hazardous sources
Predicted hazard
Countermeasures in
operation
Countermeasures in
cleaning, inspection,
and parts exchange
A
Motor and
compressor coupling
Refer to Figure 1-1
Caught in due to contact
Install coupling cover
and prohibit opening.
Keep away.
Turn off motor main
power and control
power, and conduct
lockout/tagout.
B
Motor terminals
Electric shock caused by
contact with live wires or
electrical leakage
Keep away.
Do not open terminal
boxes.
Do not touch terminal
boxes.
Turn off motor main
power and control
power, and conduct
lockout/tagout.
C
Compressor
low-stage side
suction casing
Refer to Figure 1-1
Frostbite due to contact
Contact with or inhalation of
hazardous substances
generated by leakage of
refrigerant or the like
Keep away and do not
touch.
Wear protective gear.
Detect gas leakage.
Wear protective gear.
Work under room
temperature.
D
Compressor
intermediate piping
(low-stage discharge
port to high stage
suction port)
Refer to Figure 1-1
Burn injury due to contact
Contact with or inhalation of
hazardous substances
generated by leakage or
spout of refrigerant or the like
Keep away and do not
touch
Wear protective gear
Gas leakage detection
Wear protective gear
Work in temperatures
below 40 °C
E
Compressor
high-stage side
discharge casing and
discharge piping
Burn injury due to contact
Contact with or inhalation of
hazardous substances
generated by leakage or
spout of refrigerant or the like
Keep away and do not
touch.
Wear protective gear.
Detect gas leakage.
Wear protective gear.
Work at a temperature
of not higher than 40°C.
F
Check valves/service
valves and joints on
each section of the
package unit
Contact with or inhalation of
hazardous substances
generated by mishandling or
leakage
Frostbite or burn due to
contact
Sufficient ventilation
Indicate valve
open/close state.
Keep away and do not
touch.
Wear protective gear.
Sufficient ventilation
Wear protective gear.
Tagout for controlled
valve
G
Solenoid
valves/electric valves
on each section of the
package unit
Electric shock caused by
contact with live wires or
electrical leakage
Pinched due to contact with
driving part
Install protective cover
on terminals, and
prohibit opening.
Keep away and do not
touch.
Wear protective gear.
Turn off each breaker
and the control power,
and conduct
lockout/tagout.
Wear protective gear.
H
Electric components
in each section of the
package unit (oil
heater, protective
switch, etc.)
Electric shock caused by
contact with live wires or
electrical leakage
Pinched due to contact with
driving part
Install protective cover
on terminals, and
prohibit opening.
Keep away and do not
touch.
Wear protective gear.
Turn off each breaker
and the control power,
and conduct
lockout/tagout.
Wear protective gear.
I
Package unit oil
drains
Contact with hazardous
substances generated by
leakage or spout
Burn caused by contact with
high-temperature fluid
Sufficient ventilation
Keep away and do not
touch.
Wear protective gear.
Sufficient ventilation
Wear protective gear.
Work at a temperature
of not higher than 40°C.
J
Noises
Damage caused by noise
Wear protective gear.
—

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.3 Residual Risks
1-5
Figure 1-1 Locations of Hazardous Sources (compressor)
Photo 001 Locations of Hazardous Sources (compressor)

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.4 Safety Devices
1-6
1.4 Safety Devices
For safe use and protection of this product, make sure to attach safety devices to this product in
accordance with the regulations and the following instructions.
Safety devices cannot be kept in normal condition unless inspected and maintained at regular intervals.
Their maintenance and inspection need to be performed as an important part of the
maintenance/inspection work project. Provide users of this product with necessary information on the
safety devices, for example, types of the safety devices, installation position, function, and inspection
method of safety related devices.
Check the safety devices after turning on the power and before operation of this
product. If they do not operate normally, immediately take repair or replace
safeties before starting this product.
1.4.1 Emergency Stop Button
Overview/Function/Purpose
The emergency stop buttons are used to stop the compressor operation immediately if an
emergency occurs in this product.
Installation Positions
On the control board and in the operation control room
Stop/Restoration Methods
The operating procedures for the emergency stop button, i.e., how to stop the operation and restore
the normal operating condition, must be clearly defined and the information provided to the user of
this product.
Inspection Method/Cycle
The emergency stop buttons must be tested before commissioning and must also be periodically
re-tested after that. The inspection procedures and the inspection interval for the emergency stop
button must be clearly defined and the information provided to the user of this product.
1.4.2 Breakers of Motor Main Power and Control Power
(with Lockout/Tagout Mechanism)
Overview/Function/Purpose
Turn off the main motor and control power, and if there is any possibility of danger during work
(especially during cleaning, maintenance, inspection, or troubleshooting), lockout/tagout devices
must be used on the breakers of the main motor and control powers to prevent injuries to workers in
case the power is turned on accidentally during work.
Methods of Performing and Releasing Lockout/Tagout
Make sure to clearly notify methods of performing and releasing lockout/tagout referring to the
regulations created by Occupational Safety & Health Administration (OSHA) or local governing
body.
Inspection Method/Cycle
The inspection procedures and the inspection interval for the lockout/tagout devices, must be
clearly defined and the information provided to the user of this product.

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.4 Safety Devices
1-7
1.4.3 Compressor Protective Devices
Be sure to adjust the set values and check operation of the protective devices at
the commissioning.
Overview/Function/Purpose
These protective devices are used to protect this product.
Protecting from discharge temperature rise (DT)
This device activates and stops the compressor operation when the compressor discharge
temperature gets equal to or higher than the set value.
Install a temperature sensing port to the discharge pipe.
Protecting from oil temperature rise (OT)
This device activates and stops the compressor operation when the compressor oil
temperature gets equal to or higher than the set value.
Install a temperature sensing port to the oil supply pipe of the package unit (after the oil
cooler).
Protecting from high pressure (HP)
This device activates and stops the compressor operation when the compressor discharge
pressure gets abnormally high due to mishandling of the compressor or suspension of water
supply to the condenser. This device prevents explosion of the equipment and components.
Install a pressure sensing port to the discharge pipe.
Protecting from intermediate pressure (IP)
This device activates when the intermediate pressure of the compressor gets equal to or
higher than the set value and properly controls the compressor. In some cases, this device
stops the compressor operation. Install a pressure output port to the package unit's
intermediate gas pipe (or compressor's intermediate gas pressure output port).
Protecting from suction pressure drop (LP)
This device activates and stops the compressor operation when the compressor suction
pressure gets equal to or lower than the set value.
Install a pressure sensing port to the suction pipe.
Protecting from oil pressure (OP)
This device activates and stops the compressor operation when the differential pressure to
supply oil to the compressor (= lubrication oil supply pipe pressure −compressor discharge
pressure) gets equal to or lower than the set value, due to insufficient lubricating oil, clogged
filter or mixture of refrigerant into the lubrication oil. This device prevents the sliding portion
from being abnormally worn or seized.
Install a pressure sensing port to the package unit's oil supply pump (after the oil pump) and
the discharge pipe.
Protecting from motor over-current (OCR)
This device activates and applies appropriate control when the current gets equal to or higher
than the set level flows. In some cases, this device stops the compressor operation.
This device is normally installed inside the control panel.

2202MYJE-MY-C8-N_2018.02.
Chapter 1 Safety
Compound 2-stage Screw Compressor 3225**C 1.4 Safety Devices
1-8
Connection Positions and Settings
Specify the connection position and setting for each compressor protective device, and make sure
to provide users of this product with them.
Make sure that the set values do not exceed the operating limits shown in Chapter 2, section 2.3.2
and Table 2-2 in this manual.
Inspection Method/Cycle
Compressor protective devices require operation tests and confirmation of the settings calibration
before commissioning as well as at regular intervals.
Specify the inspection methods/intervals of the compressor protection devices, and make sure to
provide users of this product with such information.
In the operation test, check that alarms and protective devices operate normally
by using devices such as pressure tester. Do not operate the compressor with all
the valves closed, or in any other dangerous conditions.
If the protection from oil pressure (OP), high pressure (HP) activates, do not
restart operation until the cause of activation is removed.

2202MYJE-MY-C8-N_2018.02.
Chapter 2 Compressor Specifications and Structure
Compound 2-stage Screw Compressor 3225**C 2.1 Overview of MYCOM 3225**C
2-1
Chapter 2 Compressor Specifications and Structure
2.1 Overview of the 3225**C
The 2-stage compression system, which has hitherto required two units of standard-type screw
compressor for its embodiment, can now be realized by a single unit of compound 2-stage screw
compressor.
Generally, screw compressors use oil injection to keep discharge temperature at a low level during
operation without loss of volumetric efficiency even at high compression ratios. It can, therefore, be
operated with a single-stage compression system even at evaporative temperatures near -40°C.
However, for normal use at low temperatures, a 2-stage compression system is applied in order to
improve kW/RT (ratio of power consumption versus cooling ability). If the 2-stage compression system
is configured with standard-type screw compressors, at least two screw compressor units need to be
installed, one on the high-stage and the other on the low-stage, which inevitably requires double
installation of the entire system including machinery, motors, utilities, etc.
This 2-stage screw compressor is produced to solve this problem. It is a single unit that has two
single-stage compressor units combined into one.
The 3225**C model has a capacity control mechanism for startup load reduction on the high-stage, and
a capacity control mechanism for coping with load change on the low-stage.
In addition, there are four rotor lengths for the low-stage and three rotor lengths for the high-stage.
Moreover, customer is able to select each low-stage and high-stage volume ratio from two
specifications. Employing these combinations of each specification, 3225**C is providing a high
versatility that can satisfy a wide range of operation conditions required by different applications at the
load side. Therefore, the 3225**C models are the long-selling products which last to
more than 30 years since the developed in 1982 as the large sized compound 2-stage screw
compressor.
2.2 Model Designation of the Compressor
This manual describes 3225**C-*B*-51 and 3225**C-*B*-61 models.
The meaning of the type designation, which is engraved on the MODEL column of the compressor
nameplate, is as follows.
*3225**C-*B*-51/61
5: Power frequency (6: 60Hz)
1: Indicates that it is a motor directly connected type.
* Unless specifically specified, machines manufactured in
September, 2010 or after do not have this indication engraved
on their nameplate.
Vi (volume ratio) specified for the high-stage discharge port,
standard value of which is Lor M
Means a booster (low-stage machine)
Vi (volume ratio) specified for the low-stage discharge port, standard
value of which is Lor M
Stands for Compound (compound 2-stage machine)
Specifications of high-stage rotor length, which is L, Mor S
Specifications of low-stage rotor length, which is LL, L, Mor S
High-stage rotor diameter of 250
Low-stage rotor diameter of 320
Indicates working fluid
(Example: N = Ammonia, F= Fluorocarbon, P = Propane, HE = Helium)

2202MYJE-MY-C8-N_2018.02.
Chapter 2 Compressor Specifications and Structure
Compound 2-stage Screw Compressor 3225**C 2.3 Compressor Specifications
2-2
2.3 Compressor Specifications
2.3.1 Standard Specifications
Table 2-1 3225**C Screw Compressor Specifications (1/2)
Items
Model
LLLC
LLMC
LLSC
LLC
LMC
LSC
Product mass
kg
4150
4100
4020
3440
3390
3310
Low-stage swept volume
@3550 min-1 /2950 min-1
m3/h
6740
/5600
6740
/5600
6740
/5600
5700
/4740
5700
/4740
5700
/4740
High-stage swept volume
@3550 min-1 /2950 min-1
m3/h
2840
/2360
2380
/1980
1900
/1580
2840
/2360
2380
/1980
1900
/1580
Working fluid (Refrigerant)
-
Ammonia, Hydrofluorocarbon, etc.
Design pressure
MPa
2.6
Capacity control (Actual load)
%
10 to 100
Rotation direction
-
Counterclockwise viewed from motor
Connected
pipe size
Low-stage suction
flange
-
JIS 20K 350A (14”)
Low-stage discharge
flange
-
JIS 20K 200A (8”)
High-stage suction
flange
-
JIS 20K 200A (8”)
High-stage discharge
flange
-
JIS 20K 150A (6”)
Journal lubrication
(low-stage)
-
JIS 20K 40A (1-1/2”)
Journal lubrication
(High-stage)
-
JIS 20K 25A (1”)
Oil injection
lubrication
-
JIS 20K 20A (3/4”)
Oil return Inlet
(Rotor casing)
-
JIS 20K 32A (1-1/4”)
Oil return outlet
(Low-stage Bearing
cover)
-
JIS 20K 32A (1-1/4”)
Oil return outlet
(High-stage Suction
cover)
-
JIS 20K 20A (3/4”)
Low-stage capacity
control
-
Load: Rc3/8, Unload: Rc3/8
High-stage capacity
control
-
Load: Rc3/8・Rc1/2, Unload: Rc3/8
Unless otherwise noted, the pressure unit MPa represents the gauge pressure
in this manual.
For limits of working temperature and pressure, see "2.3.2 Operation Limits" in
this manual.