mycom K Series User Manual

2200Q2JE-HO-KHM-N_2015.02.
Chapter 5 Maintenance and Inspection
Ammonia Semi-hermetic Motor with K-series Compressor 5.1 Precautions for Maintenance
5-5
5.3 Disassembly
5.3.1 Refrigerant Gas Recovery
Since the semi-hermetic motor is integrated with the compressor, the ammonia refrigerant inside must
be recovered before overhauling.
There are a few methods of recovering the refrigerant. For example, one method is to operate the
refrigerator, close the supply source valve, turn the gas into liquid, and recover the liquid at the receiver.
Another method is to use a refrigerant recovery machine to recover the liquid. As such, choose the
means that best meets your purpose and legal requirement.
Prepare a working flow sheet of the system beforehand. Prior to the recovery work, check the valves to
be controlled during the recovery work by comparing them with the ones in the flow sheet, and clearly
note the valves to be operated, other connected devices, and tubes on the flow sheet.
Two flow sheets must be prepared, i.e., one at the foreman and the other for posting in the workplace.
In addition, prepare a work procedure document for the refrigerant recovery work to reflect the actual
conditions of the workplace, and sufficiently share the work details among all the coworkers through
checking and confirmation before actually starting the work.
The gas mask and other protective gears required at each stage of refrigerant recovery work must be
prepared before starting the work.
 Before the work, be sure to check and communicate the work details and procedures
among all coworkers, and carry out hazard prediction activities based on the
information shared. Neglecting to do this will increase the risk of on-the-job accidents
and injuries to a considerable level.
 All the valves that have been opened or closed during the work must be prevented from
accidental operation through proper lock-out and tag-out procedures.
If the lubricating oil used is compatible with the ammonia refrigerant, a large amount of refrigerant
should be contained in the oil. Accordingly, after the refrigerant has been recovered once, the
refrigerant contained in the oil will be evaporated to increase the pressure inside the crankcase. As
such, be sure to recover the refrigerant repeatedly for a few times, until the pressure becomes low and
no more increased.
After completing the recovery work, shut down the related drive power and control power, and securely
carry out the lock-out and tag-out procedures.
5.3.2 Draining the Lubricating oil
As soon as the refrigerant recovery work is completed, drain
the lubricating oil remaining in the compressor crank case [1].
Connect a hose of pipe to the oil supply and discharge valve
located at bottom left of the compressor oil pump, and drain
the lubricating oil into a container. Applying a pressure of 0.1
MPa or so by using nitrogen gas or dry compressed air
makes the draining easier. If the pressure is applied, be sure
to vent the gas to bring the pressure back to the atmospheric
pressure after draining the lubricating oil.
Oil Supply and Discharge Valve
 When performing overhaul only motor jacket block described in Section 5.3.1.1, draining the
lubricating oil is not required.

mycom K Series Specifications

General

Brand	mycom
Model	K Series
Category	Engine
Language	English