mycom 2016 C Series Instruction Manual page 112

Chapter 6 Troubleshooting
Table 6-1 describes typical trouble symptoms of compressors, their causes and actions to be taken. For
information about troubleshooting for the unit or the whole refrigeration cycle, refer to the instruction
manual of the unit.
Symptom
01 Compressor Power source is off.
does not
start up.
Main motor failure
"Micro-switch and
micro-switch cam"
of the indicator do
not sense capacity
control of 0%.
Defective capacity
control oil supply
line
Oil pressure not
detected
Cooling water
circulation is not
confirmed.
Failure of magnet,
relay, etc. in
compressor startup
circuit
02 Compressor Low pressure
stops protection circuit
immediately activates.
after
startup.
Compound 2-stage Screw Compressor 2016**C
Table 6-1 Troubleshooting
Direct cause
Mostly caused by
forgetting to turn on
after inspection.
Mostly caused by
activation of
overload protection
circuit.
Micro-switch failure
Loosening of
micro-switch or
micro-switch cam
set screw due to
vibration.
Improper
adjustment of oil
flow control valve
(throttled
excessively).
Leak/clogging in
piping or solenoid
valve
Failure of oil
pressure protection
device, pressure
sensor, relay, etc.
Pressure pipe is
clogged.
Failure of devices
such as cooling
water pump and
related circuits
Circulation route is
clogged.
Aging degradation
Poor installation
environment
Insufficient
refrigerant flow
Root cause
Use a check sheet for
post-inspection actions and
implement finger pointing and call
check to prevent forgetting.
Refer to the operation manual of the
motor for details including other
causes and actions.
Replace.
Adjust the position of the cam and
switch, and tighten them.
Use thread locking agent when
necessary.
When compressor's vibration is
unusually high, see Item No. 12
"Compressor generates abnormal
vibration and/or sound".
Readjust.
Remove cause, and check oil for
contamination/replace oil.
Identify defective devices,
investigate causes of failure and
take necessary actions.
Then, replace failed device(s).
Remove clogging, and check oil for
contamination/replace oil.
Identify defective devices,
investigate causes of failure and
take necessary actions.
Then, replace failed device(s).
Remove the clogging.
Replace with new one.
Replace ventilation fans, etc. if
defective.
Improve temperature, humidity and
ventilation at the installation site.
To correct insufficient refrigerant,
check leak, stop leak and then add
refrigerant.
* Also pay attention to moisture
entering into the system.
6-1
2200LZJE-HO-C6-N_2013.12.
Chapter 6 Troubleshooting
Action