mycom i125S - User Manual

Questions and Answers

O
Olivia TaylorAug 15, 2025
What to do if my mycom Air Compressor stops immediately after startup?
- S
  Sandra OconnorAug 16, 2025
  If your mycom Air Compressor stops immediately after starting, it could be due to the activation of the low pressure protection circuit. To resolve this, check for refrigerant leaks, stop any leaks found, and then add refrigerant. Also, be aware of potential moisture entering the system. Alternatively, the issue might stem from a malfunctioning low pressure protection switch, pressure sensor, or relay. Identify any defective devices, investigate the cause of the failure, take necessary actions, and replace the failed device.
Y
ywalshAug 22, 2025
How to troubleshoot a mycom Compressor that does not start up?
- C
  corey74Aug 22, 2025
  If your mycom Compressor isn't starting, several factors could be at play. First, ensure the power source is active; use a checklist to confirm post-inspection actions. A main motor failure could also be the cause, so consult the motor's instruction manual for detailed troubleshooting. Check that the cooling water is circulating correctly, and if not, identify and replace any defective devices. A clogged circulation route can also prevent startup, so clear any blockages. Additionally, a faulty magnet, relay, or other component in the startup circuit may be the culprit, requiring replacement. Finally, a poor installation environment can hinder performance; improve temperature, humidity, and ventilation, and replace any defective ventilation fans.
N
nicolewilliamsAug 25, 2025
What to do if my mycom Compressor stops immediately after starting?
- T
  Taylor RobinsonAug 26, 2025
  If the mycom Compressor stops immediately after starting, it could be due to the low pressure protection circuit activating. To fix this, check for refrigerant leaks, stop any leaks, and then add more refrigerant. Also, be mindful of moisture entering the system. Alternatively, the issue might stem from a failure in the low pressure protection switch, pressure sensor, or relay. In this case, identify the defective device, investigate the cause of failure, take necessary actions, and then replace the failed device.
H
Hunter MitchellAug 30, 2025
Why does my mycom Compressor generate abnormal vibration and/or sound?
- T
  Theresa AllenAug 31, 2025
  If your mycom Compressor is generating abnormal vibration or sound, one potential cause is excessive vibration of the motor shaft. If other causes are ruled out, consider overhauling the compressor at a facility equipped for dynamic balance measurement and adjustment. Another cause could be liquid flow-back during startup, which often presents with a loud, abnormal noise; identify and address the root cause, then overhaul and inspect the compressor. Liquid flow-back during operation, indicated by notable frosting on the suction side, can also cause these issues. To prevent this, avoid rapid changes in heat load that exceed the set value of the heat exchanger and expansion valve.
G
Gregory FrancisSep 2, 2025
What to do if there is a leak from the mechanical seal of my mycom Compressor?
- M
  Michelle TurnerSep 2, 2025
  If you notice a leak from the mechanical seal of your mycom Compressor, it could be due to an initial leak after replacement, which should decrease gradually as the sliding faces settle. Ensure the leak doesn't increase continuously. The duration of this initial leak is approximately 200 hours. Alternatively, the sliding surface may be roughened due to overheating. In this case, review the operating conditions to reduce the frequency of starting and stopping the equipment. Finally, deteriorated parts can also cause leaks; replace them as needed, referring to causes and actions for "Overheating of sliding surface."
J
Jessica KennedySep 8, 2025
What causes capacity control malfunction in my mycom Compressor?
- J
  Jo WolfSep 9, 2025
  If the capacity control is malfunctioning on your mycom Compressor, it could be due to a failure of the capacity control solenoid valve or related relays. If these parts are deteriorated, replace them. If water leakage is the cause, remove the source of the leak and replace any defective parts. Internal leakage of the capacity control solenoid valve can also cause issues, requiring replacement of the valve. Lastly, a defective capacity control oil supply line can lead to malfunction; remove the cause of the defect, and check the oil for contamination, replacing it if necessary.
E
Elizabeth WilsonSep 12, 2025
What causes damaged thrust bearings in my mycom Compressor?
- J
  Jeffrey RyanSep 12, 2025
  If your mycom Compressor has damaged thrust bearings, one potential cause is excessive thrust stress due to high suction pressure exceeding the level set by operating conditions. Re-examine the operating conditions and improve them if possible. If improvement is difficult, review the maintenance interval management. Another cause could be faulty assembly, such as lock nuts tightened insufficiently, lock washer tab not bended, rotation stopper not set to thrust bearing gland, or spring washer not assembled. Tighten lock nuts to the specified torque or torque angle and record data on the assembly check sheet to prevent omission of work steps.
M
mcclainstephanieNov 17, 2025
Why my mycom i125S does not start up?
- S
  Sabrina MorrisonNov 17, 2025
  If your mycom Air Compressor doesn't start, it could be due to several reasons. First, ensure the power source is on, using a check sheet for post-inspection actions. It could also be due to main motor failure, in which case you should refer to the motor's instruction manual. Another potential cause is the cooling water circulation not being confirmed, which requires identifying defective devices, investigating the causes of failure, taking necessary actions, and replacing any failed devices. A clogged circulation route can also prevent startup; if this is the case, remove the clogging. Also, check for failure of the magnet, relay, etc. in the compressor startup circuit. Defective devices should be identified and replaced with a new one. Lastly, a poor installation environment can cause st...
B
Brandon HopkinsNov 27, 2025
Why is the pressure abnormally high in my mycom Compressor?
- J
  jmanningNov 27, 2025
  If you're experiencing abnormally high pressure (abnormal discharge pressure) in your mycom Compressor, several factors could be the cause. A heat exchange failure in the condenser might be the reason; try cleaning and washing it, using chemical cleaning if heavily contaminated. A failure in the fan motor, thermo switch, water spraying pipes, or cooling water pumps could also be responsible; identify and replace any defective devices. Check for faulty adjustment of cooling water or brine flow, readjusting the valve if it's manually controlled, or investigating the cause if it's an automatic valve. Other issues could include insufficient cooling water flow, so inspect filters for clogging, check for leaks, and examine water supply routes. If the heat exchanger performance is deficient, re-e...

Summary

Preface

Revision History

Details changes made to the manual across different revisions.

Warranty and Disclaimer

Warranty Clauses

Outlines conditions under which MAYEKAWA will repair or replace parts.

Disclaimer of Warranty

Lists conditions under which MAYEKAWA's warranty is exempted.

Important Information

Intended Use of this Product

Specifies the product's general purpose for refrigeration and cold storage.

Important Information for Safe Use of this Product

Provides essential safety rules for operating and handling the product.

About This Manual

Provides details on manual updates, copyright, and usage guidelines.

Structure of This Manual

1 Safety

Outlines safety information for workers and product handling.

1 Safety

1.1 Strict Requirements and Prohibitions

Lists mandatory do's and don'ts for safe operation and maintenance.

1.2 Warnings

Explains warning symbols and their meanings for potential hazards.

1.3 Residual Risks

Identifies potential hazards and countermeasures during operation and maintenance.

Chapter 2 Compressor Specifications and Configuration

2.1 Features of i-Series Compressor

Describes the key features and advantages of the i-Series compressor.

2.2 Model Designation of the Compressor

Explains the meaning of the compressor model designation codes.

2.3 Compressor Specifications

Provides detailed technical specifications for the i-Series compressors.

Chapter 2 Compressor Specifications and Configuration

2.3.3 Alarm Set Values

Specifies alarm and stop set values to protect the compressor.

2.3.4 Outer Dimensions

Shows detailed dimensional drawings for various i-Series compressor models.

Chapter 2 Compressor Specifications and Configuration

2.4 Configuration of Compressor

Illustrates the internal structure with sectional and exploded views.

2.4.1 Sectional Views

Provides longitudinal and cross-sectional views of compressor components.

Chapter 2 Compressor Specifications and Configuration

2.4.2 Exploded Views

Presents exploded views of compressor parts for identification.

2.4.3 Parts Configuration Table

Lists part numbers, names, codes, and quantities for i125S/L and i160*.

Chapter 3 Installation

3.1 General Precautions for Installation

Covers general safety and procedural precautions before installation.

3.2 Installation Works

Details the steps involved in installing the compressor unit.

Chapter 3 Installation

3.2.1 Unpacking

Instructs on checking the compressor for damage after unpacking.

3.2.2 Storage

Provides guidelines for storing the compressor before installation.

3.2.3 Transportation

Details safe procedures for transporting the compressor unit.

Chapter 3 Installation

3.2.4 Preparation for Installation

Outlines necessary preparations like space, lighting, and ventilation.

3.2.5 Installation

Covers the physical installation and piping connection procedures.

Chapter 3 Installation

3.2.5.1 Refrigerant Piping

Provides guidelines for connecting the refrigerant piping to the compressor.

3.2.5.2 Equipment and Devices for Protection of the Compressor

Details installation of protective devices like oil filters and alarms.

Chapter 3 Installation

3.2.6 Airtightness Test

Explains how to perform an airtightness test on the installed unit.

3.2.7 Lubricating Oil Charge

Details the procedure for charging lubricating oil into the compressor.

Chapter 3 Installation

3.2.7.1 Initial Charge of Lubricating oil

Outlines the procedure for the initial filling of lubricating oil.

3.2.9 Check after Installation

Specifies final checks to be performed after installation before commissioning.

Chapter 4 Compressor and Package Unit Operation

4.1 Lubricating Oil (Refrigerant Oil)

Covers selection, management, and handling of lubricating oil.

4.1.1 Precautions for Selecting the Lubricating Oil

Discusses factors to consider when selecting the appropriate lubricating oil.

Chapter 4 Compressor and Package Unit Operation

4.1.2 Recommended Lubricating Oils

Lists recommended lubricating oils for different refrigerant types.

4.1.3 Change of Lubricating Oil Brand

Provides guidance on changing the brand of lubricating oil.

Chapter 4 Compressor and Package Unit Operation

4.1.4 Precautions for Handling Lubricating Oil

Advises on proper handling and storage of lubricating oil.

4.1.5 Lubricating Oil Management Criteria

Details criteria for managing and analyzing lubricating oil quality.

Chapter 4 Compressor and Package Unit Operation

4.1.6 Lubricating Oil Replacement Timing

Explains when to replace lubricating oil based on operation time.

4.2 Precautions for Operation

Covers essential precautions to ensure safe and efficient operation.

Chapter 4 Compressor and Package Unit Operation

4.2.1 Prevention of Liquid Flow-back

Explains the phenomenon of liquid flow-back and how to prevent it.

4.2.2 Purging of Non-Condensable Gases

Details the procedure for purging non-condensable gases from the system.

Chapter 4 Compressor and Package Unit Operation

4.3 When Stopping the Compressor for a Long Time

Provides instructions for safely stopping the compressor for extended periods.

Chapter 5 Maintenance and Inspection

5.1 Precautions for Maintenance and Inspection

Lists essential safety precautions before performing maintenance or inspection.

Chapter 5 Maintenance and Inspection

5.2 Maintenance and Inspection List

Provides a list of daily management and inspection items.

5.2.1 Daily Management

Details daily inspection items and how to record operational data.

Chapter 5 Maintenance and Inspection

5.2.2 Periodic Inspection

Outlines periodic inspection items and their recommended intervals.

5.2.3 Guidelines for Compressor Overhaul Interval

Provides recommendations for compressor overhaul intervals based on operating conditions.

Chapter 5 Maintenance and Inspection

5.3 Compressor Disassembly Preparation

Covers essential preparations before disassembling the compressor.

5.3.1 Disassembly Tools and Work Place

Lists required tools and describes the ideal work environment for disassembly.

Chapter 5 Maintenance and Inspection

5.3.2 Replacement Parts

Lists standard replacement parts for i-series compressor overhaul.

5.3.3 Refrigerant Gas Treatment

Details procedures for recovering and handling refrigerant gas before disassembly.

Chapter 5 Maintenance and Inspection

5.3.4 Removing Parts Connected to the Unit

Explains how to disconnect external parts from the compressor unit.

5.3.5 Removing and Lifting the Compressor

Provides guidance on safely removing and lifting the compressor.

Chapter 5 Maintenance and Inspection

5.3.6 Removing Oil from Compressor

Details the process of draining oil from the compressor.

5.4 Disassembly and Inspection

Outlines general precautions for disassembling and inspecting compressor parts.

Chapter 5 Maintenance and Inspection

5.4.1 Shaft Seal Block

Describes the disassembly and inspection of the shaft seal assembly.

5.4.1.1 Disassembly

Details the step-by-step process for disassembling the shaft seal block.

Chapter 5 Maintenance and Inspection

5.4.1.2 Inspection

Provides guidance on inspecting the shaft seal assembly for defects.

5.4.2 Bearing Cover

Covers the disassembly and inspection of the bearing cover.

Chapter 5 Maintenance and Inspection

5.4.3 Balance Piston

Details the disassembly and inspection of the balance piston.

5.4.4 End Cover

Covers the disassembly and inspection of the end cover.

Chapter 5 Maintenance and Inspection

5.4.5 Thrust Bearing Block

Explains the disassembly and inspection of the thrust bearing block.

5.4.5.1 Disassembly

Details the step-by-step process for disassembling the thrust bearing block.

Chapter 5 Maintenance and Inspection

5.4.5.2 Inspection

Provides guidance on inspecting the thrust bearing block and related parts.

5.4.6 Bearing Head

Covers the disassembly and inspection of the bearing head.

Chapter 5 Maintenance and Inspection

5.4.7 Rotors

Details the disassembly and inspection of the compressor rotors.

5.4.7.1 Disassembly

Outlines the steps for disassembling the rotors.

Chapter 5 Maintenance and Inspection

5.4.7.2 Inspection

Provides guidance on inspecting the rotors for wear or damage.

5.4.8 Radial Bearings

Covers the disassembly and inspection of radial bearings.

Chapter 5 Maintenance and Inspection

5.4.9 Suction Strainer and Check Valve

Details the disassembly and inspection of the suction strainer and check valve.

5.4.9.1 a Disassembly (i125*)

Provides disassembly steps for the suction strainer in i125* models.

Chapter 5 Maintenance and Inspection

5.4.9.1 b Disassembly (i160*)

Provides disassembly steps for the suction strainer in i160* models.

5.4.10 Unloader

Covers the disassembly and inspection of the unloader mechanism.

Chapter 5 Maintenance and Inspection

5.5 Reassembly

Provides general precautions and steps for reassembling the compressor.

Chapter 5 Maintenance and Inspection

5.5.1 Unloader

Details the reassembly procedure for the unloader.

5.5.2 Rotor and Inner Race of Radial Bearing

Explains how to reassemble the rotor and radial bearing inner race.

Chapter 5 Maintenance and Inspection

5.5.3 Bearing Head

Details the reassembly of the bearing head.

5.5.4 Outer Race of Radial Bearing

Explains how to reassemble the outer race of the radial bearing.

Chapter 5 Maintenance and Inspection

5.5.5 Suction Strainer and Check Valve

Details the reassembly of the suction strainer and check valve.

5.5.6 Adjustment of Thrust Bearing and End Clearance

Explains how to adjust thrust bearing and end clearance.

Chapter 5 Maintenance and Inspection

5.5.6.1 End Clearance Measurement

Details the procedure for measuring the end clearance.

5.5.6.2 End Clearance Adjustment

Explains how to adjust the end clearance if it is outside the specified value.

Chapter 5 Maintenance and Inspection

5.5.7 Balance Piston

Details the reassembly of the balance piston.

5.5.8 Bearing Cover

Explains the reassembly of the bearing cover.

Chapter 5 Maintenance and Inspection

5.5.9 Shaft Seal Block

Details the reassembly of the shaft seal block.

5.5.10 End Cover

Explains the reassembly of the end cover.

Chapter 6 Troubleshooting

01 Compressor does not start up

Lists direct causes, root causes, and actions for compressor startup failure.

Chapter 6 Troubleshooting

02 Compressor stops immediately after startup

Details troubleshooting steps for compressors that stop shortly after startup.

03 Abnormally low pressure (Low suction pressure)

Guides on diagnosing and resolving issues related to low suction pressure.

Chapter 6 Troubleshooting

04 Low oil pressure (Low oil supply pressure)

Provides troubleshooting steps for low oil pressure or supply issues.

05 Abnormally high pressure (Abnormal discharge pressure)

Guides on diagnosing and resolving abnormal discharge pressure.

Chapter 6 Troubleshooting

06 Discharge temperature is abnormally high

Details troubleshooting steps for excessively high discharge temperatures.

07 Leak from mechanical seal

Provides troubleshooting for leaks from the mechanical seal.

Chapter 6 Troubleshooting

08 Squeaking sound from mechanical seal part

Addresses the issue of squeaking sounds from the mechanical seal.

09 Capacity control malfunction

Guides on troubleshooting capacity control malfunctions.

Chapter 6 Troubleshooting

10 Compressor generates abnormal vibration and;or sound

Details troubleshooting for abnormal vibration and sound from the compressor.

Chapter 7 Related Documents

7.1 Tightening Angles for Lock Nuts

Explains how to manage tightening torque of lock nuts using angle ranges.

7.2 Disassembly Tools

Lists the specific tools required for compressor disassembly.

Chapter 7 Related Documents

7.3 Flange Motor and Connection Flange Size

Provides a table of flange motor and connection flange sizes.

Appendix 1: Basic Points for Design and Manufacturing for the Compressor Package

1-1 Basic Flow of the Package Unit

Describes the basic flow and components of the compressor package unit.

Appendix 1: Basic Points for Design and Manufacturing for the Compressor Package

1-2 Basic Flow of the Oil Cooler

Illustrates the basic flow of the oil cooling system.

1-3 Oil Temperature Control

Explains methods for controlling the lubricating oil temperature.

Appendix 1: Basic Points for Design and Manufacturing for the Compressor Package

1-4 Economizer

Describes the economizer port and its use for refrigerating effect.

1-5 Oil Separator

Details the roles and design considerations for the oil separator.

Appendix 1: Basic Points for Design and Manufacturing for the Compressor Package

1-6 Protection Devices

Outlines the necessity and types of protective devices for the compressor.

1-7 Power Supply and Control Devices

Shows examples of power control circuit diagrams and components.

Appendix 2: Basic Points of Design and Manufacturing for the Compressors Multi- package

2-1 Preface

Introduces basic packaging instructions for multi-package i-series compressors.

2-2 Reference Flow and Configuration Components for Multi-package

Illustrates the flow and components for multi-package compressor systems.

Appendix 2: Basic Points of Design and Manufacturing for the Compressors Multi- package

2-2-2 Oil Separator

Discusses oil separator selection and considerations for multi-package units.

2-2-3 Pressure Regulator for Differential Oil Supply Pressure

Details the use of pressure regulators in multi-package oil supply systems.

Appendix 2: Basic Points of Design and Manufacturing for the Compressors Multi- package

2-2-4 Oil Cooler

Covers oil cooler selection and shared usage in multi-package systems.

2-2-5 Oil Filter and Oil Line

Specifies oil filter precision and oil line connections for multi-package units.

Appendix 2: Basic Points of Design and Manufacturing for the Compressors Multi- package

2-2-6 Stop Valve and Safety Valves

Discusses the installation of stop and safety valves in multi-package systems.

2-3 Economizer

Explains economizer types used in multi-package systems.

Appendix 2: Basic Points of Design and Manufacturing for the Compressors Multi- package

2-4 Protection Devices and Control Devices

Covers protection and control devices for multi-package units.

mycom i125S Specifications

General

Brand	mycom
Model	i125S
Category	Air Compressor
Language	English

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