mycom i125S User manual

2203M4JE-MY-iS2-N_2017.04.
i-Series Screw Compressor
Instruction Manual i125S / i125L
i160S / i160M / i160L
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.
This manual is applied to each compressor after the serial number
shown below.
i125S: 8750303 i125L: 8770301
i160S: 8710055 i160M: 8720018 i160L: 8730030

2203M4JE-MY-iS2-N_2017.04.
Preface
Screw Compressor i-series i
Preface
Thank you for purchasing our i-series screw compressor (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.
Before installing or using this product, make sure you read this manual.
Keep this manual in a safe place near this product for quick reference.
Revision History
Title Document No. First edition issue date
i-Series Screw Compressor
Instruction manual 2203M4JE-MY-iS2-N_2017.04. April 28, 2014
Revision
No. Issue Date Major contents of revisions Created / approved by:
00 April 28, 2014 Newly is
sued as applicable to the product after May
2014, due to modification of the i-series specifications. Muta
/ Ikeda, Hirao
01 Sep. 24, 2014 Added models for IEC motor flange specifications.
Amanuma, Kato /
Ikeda, Hirao
02
June 01, 2015
Modified the constitution of Chapter 4 and Chapter 5.
Added the basic multi-packaging points using plural
i-sereis compressors.
Kitahara,
Fujimoto / Ikeda
03
April 30, 2017
Corrected 2.3.1 Standard Specifications, 2.4.3 Parts
Configuration Table . Deleted Contact Information.
Takenouchi,
Ito / Kato

2203M4JE-MY-iS2-N_2017.04.
Warranty and Disclaimer
Screw Compressor i-series ii
Warranty and Disclaimer
Warranty Clauses
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.

2203M4JE-MY-iS2-N_2017.04.
Important Information
Screw Compressor i-series iii
Important Information
Intended Use of this Product
This product is a general-purpose screw compressor for refrigeration and cold storage. 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.
Important Information 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 or warning labels. 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 the 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.

2203M4JE-MY-iS2-N_2017.04.
Important Information
Screw Compressor i-series iv
[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.
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 in which this product is used. 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 to one of our local sales offices or
service centers for a new manual. Using this product without the manual may result in safety
issues.
When you resell this product, be sure to transfer this manual to the next owner.

2203M4JE-MY-iS2-N_2017.04.
Important Information
Screw Compressor i-series v
Structure of This Manual
Chapter/Section Title Description
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
Configuration
Describes the main components of this product, functional
information,
specification, operating limits, drawings, and parts list.
3. Installation Describes the installation procedure of this product.
4. Compressor and Package
Unit Operation
Describes the precautions for operating this product
and the package
unit..
5. Maintenance and
Inspection
Describes sections and period for inspecting, and assembly and
disassembly of this product.
6. Troubleshooting Describes troubl
eshooting methods for this product in case problems
occur during operation of this product.
7. Related Documents List of disassembly tools for i-series compressor, and other information
Appendix 1 :
Packaging Points 1 Describes basic points for the design and manufacture of a i-
series
compressor package unit.
Appendix 2:
Packaging Points 2 Describes basic multi-packaging points using plural i-sereis
compressors.

2203M4JE-MY-iS2-N_2017.04.
Table of Contents
Screw Compressor i-series vi
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
Structure of This Manual....................................................................................................ⅴ
Table of Contents.................................................................................................
ⅵ
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 ................................. 1-2
1.1.1.4 Do's about Personal Protective Gear.......................................................... 1-2
1.1.1.5 Do's about the 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.................................................................................................... 1-2
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 Circuit 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 Configuration
2.1 Features of
i-Series Compressor ........................................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.................................................................................................... 2-3

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Screw Compressor i-series vii
2.3.3 Alarm Set Values................................................................................................. 2-4
2.3.4 Outer Dimensions................................................................................................ 2-5
2.4 Configuration of Compressor..................................................................2-18
2.4.1 Sectional Views ................................................................................................. 2-18
2.4.2 Exploded Views ................................................................................................. 2-24
2.4.3 Parts Configuration Table.................................................................................. 2-26
2.5 Mechanisms..............................................................................................2-33
2.5.1 Basics of the Screw Compressor ...................................................................... 2-33
2.5.2 Suction Process................................................................................................. 2-33
2.5.3 Compression Process........................................................................................ 2-34
2.5.4 Discharge Process............................................................................................. 2-34
2.5.5 About Volume Ratio (Vi).................................................................................... 2-34
2.5.6 Capacity Control Mechanism............................................................................. 2-36
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................................................................................... 3-3
3.2.5 Installation............................................................................................................ 3-3
3.2.5.1 Piping Connection ....................................................................................... 3-3
3.2.5.2 Equipment and Devices for Protection of the Compressor......................... 3-4
3.2.6 Airtightness Test.................................................................................................. 3-4
3.2.7 Lubricating Oil Charge......................................................................................... 3-4
3.2.7.1 Initial Charge of Lubricating OIL.................................................................. 3-5
3.2.7.2 Additional Charge of Lubricating Oil............................................................ 3-5
3.2.8 Charge of Refrigerant.......................................................................................... 3-5
3.2.9 Check after Installation........................................................................................ 3-5
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 .......................................................................... 4-2
4.1.2.1 Recommended Lubricating Oils for Ammonia Refrigerant.......................... 4-2
4.1.2.2 Oils for Systems Using Hydrofluorocarbon (HFC) Refrigerants.................. 4-3
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................................................................... 4-4
4.1.6 Lubricating Oil Replacement Timing.................................................................... 4-5

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Screw Compressor i-series viii
4.1.6.1 After Starting the Initial Operation .............................................................. 4-5
4.1.6.2 During Normal Operation ........................................................................... 4-5
4.2 Precautions for Operation .........................................................................4-6
4.2.1 Prevention of Liquid Flow-back ........................................................................... 4-6
4.2.2 Purging of Non-Condensable Gases................................................................... 4-6
4.3 When Stopping the Compressor for a Long Time....................................4-7
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 Compressor Overhaul Interval ..................................................... 5-6
5.3 Compressor Disassembly Preparation.....................................................5-7
5.3.1 Disassembly Tools and Work Place.................................................................... 5-7
5.3.2 Replacement Parts.............................................................................................. 5-8
5.3.3 Refrigerant Gas Treatment................................................................................ 5-10
5.3.3.1 Valves Used............................................................................................... 5-10
5.3.3.2 Refrigerant Gas Recovery......................................................................... 5-10
5.3.4 Removing Parts Connected to the Unit............................................................. 5-11
5.3.5 Removing and Lifting the Compressor.............................................................. 5-11
5.3.6 Removing Oil from Compressor........................................................................ 5-11
5.4 Disassembly and Inspection ...................................................................5-12
5.4.1 Shaft Seal Block ................................................................................................ 5-12
5.4.1.1 Disassembly.............................................................................................. 5-12
5.4.1.2 Inspection .................................................................................................. 5-13
5.4.2 Bearing Cover.................................................................................................... 5-14
5.4.2.1 Disassembly .............................................................................................. 5-14
5.4.2.2 Inspection................................................................................................... 5-14
5.4.3 Balance Piston................................................................................................... 5-15
5.4.3.1 Disassembly .............................................................................................. 5-15
5.4.3.2 Inspection .................................................................................................. 5-15
5.4.4 End Cover.......................................................................................................... 5-15
5.4.5 Thrust Bearing Block ......................................................................................... 5-16
5.4.5.1 Disassembly.............................................................................................. 5-16
5.4.5.2 Inspection .................................................................................................. 5-16
5.4.6 Bearing Head..................................................................................................... 5-17
5.4.6.1 Disassembly .............................................................................................. 5-17
5.4.6.2 Inspection .................................................................................................. 5-17
5.4.7 Rotors ................................................................................................................ 5-17
5.4.7.1 Disassembly .............................................................................................. 5-17
5.4.7.2 Inspection .................................................................................................. 5-17
5.4.8 Radial Bearings ................................................................................................. 5-18
5.4.8.1 Disassembly .............................................................................................. 5-18

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Screw Compressor i-series ix
5.4.8.2 Inspection .................................................................................................. 5-18
5.4.9 Suction Strainer and Check Valve..................................................................... 5-18
5.4.9.1a Disassembly (i125*)................................................................................... 5-18
5.4.9.1b Disassembly (i160*)................................................................................... 5-18
5.4.9.2 Inspection .................................................................................................. 5-19
5.4.10 Unloader ............................................................................................................ 5-19
5.4.10.1 Disassembly .............................................................................................. 5-19
5.4.10.2 Inspection .................................................................................................. 5-19
5.5 Reassembly ..............................................................................................5-20
5.5.1 Unloader ............................................................................................................ 5-21
5.5.2 Rotor and Inner Race of Radial Bearing............................................................ 5-21
5.5.3 Bearing Head..................................................................................................... 5-22
5.5.4 Outer Race of Radial Bearing............................................................................ 5-22
5.5.5 Suction Strainer and Check Valve..................................................................... 5-23
5.5.5.1 i125*........................................................................................................... 5-23
5.5.5.2 i160*........................................................................................................... 5-23
5.5.6 Adjustment of Thrust Bearing and End Clearance............................................5-24
5.5.6.1 End Clearance Measurement.................................................................... 5-26
5.5.6.2 End Clearance Adjustment........................................................................ 5-27
5.5.6.3 Tightening after End Clearance Adjustment..............................................5-27
5.5.7 Balance Piston................................................................................................... 5-28
5.5.8 Bearing Cover.................................................................................................... 5-28
5.5.9 Shaft Seal Block ................................................................................................ 5-29
5.5.10 End Cover.......................................................................................................... 5-31
Chapter 6 Troubleshooting
01: Compressor does not start up................................................................................ 6-1
02: Compressor stops immediately after startup.......................................................... 6-1
03: Abnormally low pressure (decrease of suction pressure)...................................... 6-2
04: Low oil pressure (low oil supply pressure)............................................................. 6-2
05: Abnormally high pressure (abnormal discharge pressure).................................... 6-3
06: Discharge temperature is abnormally high............................................................. 6-4
07: Leak from mechanical seal part ............................................................................. 6-6
08: Squeaking sound from mechanical seal ................................................................ 6-6
09: Capacity control malfunction.................................................................................. 6-6
10: Compressor generates abnormal vibration and/or sound...................................... 6-6