mycom i125S Instruction Manual page 106

Symptom
10 Compressor
generates
abnormal
vibration
and/or
sound.
Screw Compressor i-series
Direct cause
Liquid flow-back Expansion valve
during operation aperture control
* Notable frosting cannot keep up
on the suction with rapid change
side. in heat load on the
* In many cases, load side.
flow-back of mist
(steam) rather
than liquid occurs.
Heat exchange
* Sometimes,
failure in heat
gas-liquid exchanger on load
separator
side
(accumulator) is
attached to
prevent this
symptom.
* See also the
causes in item 02,
"Insufficient
refrigerant flow".
Heat exchange
failure in heat
exchanger on load
side
Heat exchange
failure in heat
exchanger on load
side
Foreign substances Welding spatter,
entering the etc. flowing from
compressor upstream side
Tools and/or waste
cloth left
uncollected after
overhauling
Damaged thrust Deterioration over
bearings. time (operated
beyond
recommended time
of replacement)
Root cause
Avoid rapid change in heat load
that exceeds the set value of
follow-up range of "heat
exchanger on load side
(evaporator)" + "expansion valve".
For details, refer to the instruction
manuals related to devices/control
on load side.
In case of frosting (icing), conduct
manual defrosting.
Set defrosting interval shorter.
If a device which is specific to the
・Related to
defrosting type fails, remove the
cause(s) and replace the
defrosting
device(s).
If a piping route which is specific
to the defrosting type gets
blocked, remove the cause(s) and
take necessary actions.
* Especially when handling hot
If ventilation around the heat
exchanger is obstructed for any
reason such as piled up load,
improve the conditions.
・Load side
* Ensure the flow of heating
conditions
Check for any blocked heat
transmission tubes or fan failure. If
any problem is found, take
necessary actions.
・Heat exchanger
conditions
Check suction strainer and/or oil
filters. Replace element if
defective.
Overhaul the compressor.
Collect foreign substances and
identify their sources. Then take
necessary measures.
The time for replacement depends
largely on operating conditions
(low pressure or high intermediate
pressure will make the life shorter,
etc.) and/or oil management
conditions. In case of a typical
refrigeration application which
basically operates in a stable
continuous mode, inspect and
replace them every 40,000 hours
or 5 years, whichever comes first.
For details, refer to Section 5.2.3.
6-8
2203M4JE-MY-iS2-N_2017.04.
Chapter 6 Troubleshooting
Action
gas defrosting systems,
thoroughly read and understand
the contents of the instruction
manuals for the units associated
with devices/control on the load
side.
medium through the heat
exchanger on the load side.