Chapter 6 Troubleshooting
UD-series Screw Compressors
6-11
Trouble
Direct causes
Factors
Actions
11
Abnormal
vibration
and/or
noise of
compressor
Entering of foreign
substances
Refer to the Direct cause “Foreign
substances entering into
compressor” above.
Excessive thrust
stress
High suction pres-
sure exceeding
operating
conditions
Re-examine operating conditions
and improve them if possible.
If it is difficult to improve,
re-examine maintenance interval
management.
Faulty assembly
* Lock nuts
tightened
insufficiently, lock
washer tab not
bended, etc.
Tighten lock nuts by using specified
torque.
Be sure to record data on the
assembly check sheet to prevent
omission of work steps.
Sympathetic
vibration
This phenomenon
occurs when the
natural frequency of
piping or support
approaches to
vibration of
compressor.
In many cases, this occurs due to
change in installation environment
such as change in piping circuit or
additional installation of devices in
the machine room, and changes in
oil levels.
→If sympathetic vibration is
suspected, contact our sales
offices or service centers.