09: Capacity Control Malfunction; Squeaking Sound From Mechanical Seal - mycom i125S Instruction Manual

Symptom
07 Leak from
mechanical
seal
08 Squeaking
sound from
mechanical
seal part
09 Capacity
control
malfunction
10 Compressor
generates
abnormal
vibration
and/or
sound.
Screw Compressor i-series
Direct cause
Deteriorated part(s) Swelled O-ring
Deteriorated seal
ring/mating ring
Incompatibility of Unsuitable
lubricating oil and lubricating oil was
operating conditions selected, or
(such as working operating
temperature range conditions have
or refrigerant) changed after
installation of the
package unit.
Poor contact of Foreign matters
sliding surfaces attached to sliding
surfaces, due to
contaminated
lubricating oil.
Faulty assembly of
parts
Human error
During initial period As the sliding
after exchange for surfaces are very
new product, hard and dense,
squeaks may be they need time to
heard from sliding fit together.
surfaces until they
fit together.
Failure of capacity Mostly caused by
control solenoid coil burnout.
valve, related
relays, or the like
Internal leakage of Aging degradation
capacity control
solenoid valve
Capacity control oil Leak/clogging in
supply line is solenoid valve
defective. gland or oil supply
piping
M rotor shaft runout Lock nut(s) and/or
is excessive. thrust bearing
gland(s) are
tightened unevenly.
Root cause
In case of liquid flow-back,
* This occurs remove the cause(s).
when the If oil heater or devices on its
lubricating oil of control circuit are defective,
refrigerating replace the defective part.
machine contains
large amount of
refrigerant.
If deteriorated over time, replace.
For other specific causes, see the
causes/action for symptom
"Overheating of sliding surface".
If possible, review the operating
conditions.
If not, see Section 4.1"Lubricating
Oil (Refrigerant Oil)" to select
suitable lubricating oil and replace
the whole quantity.
Replace the whole quantity of
lubricating oil.
Install bypass filter to oil supply
line.
Disassemble, replace parts and
reassemble.
Use assembly check sheet to
ensure confirmation.
Squeaking itself does not cause
leak from seal or deterioration in
sealing function.
Normally, squeaking is heard for
several dozens of hours, however,
it may last longer in rare cases.
→In this case, contact one of our
If deteriorated over time, replace.
If the symptom is caused by water
leakage, etc., remove the
cause(s) and then replace
defective part(s).
For details, refer to the instruction
manual of solenoid valve.
Replace.
Remove cause, and check oil for
contamination, replace oil if
necessary.
If lock nuts are not loose and parts
such as thrust bearings are free of
defects, tighten the lock nuts
and/or thrust bearing glands
evenly.
6-6
2203M4JE-MY-iS2-N_2017.04.
Chapter 6 Troubleshooting
Action
service centers.