C0210101-07-16-EN
28
* The frequency of the operations described in the table above should be considered indicative. In fact, it
may undergo variations according to the method of use of the unit and the system in which the latter is
required to operate
** The degree of tightness of the belts depends on many factors, including motor power, speed, the type and size of
the belts and pulleys, etc. It is important to know the correct degree of tightness and to set it as precisely as
possible. Tighten the belt as follows:
1.
check alignment of the pulleys of the motor shafts and fan
2.
make sure that the sides of the throat are clean
3.
apply the drive belts, loosening the tensioning system in order not to damage them by stretching them too
tight
4.
tighten the belts by gradually adjusting the tensioning system
If there are no specific instruments for measuring belt tension, the approximate method below can be followed: To
ascertain the correct tension, measure the free section T; for each belt, use a dynamometer half-way along the T to
apply a perpendicular force F capable of causing a displacement of 1.5 mm for each 100 mm of T; compare the F
value of the dynamometer with the values F' and F" in the table.
Tab.5
For units installed in aggressive climates, request air exchangers with a protective covering. In such climates the maintenance intervals
must be reduced (to be evaluated according to the specific climatic condition).
Periodic preventive maintenance intervals recommended on centrifugal compressors
Operation description
frequency
6 months
12 months
other
Ge
ner
al
Check for any visible mechanical damage to the compressor
•
Check for any excessive vibrations caused by other mechanical components operating
•
C
hec
ks
on
el
ec
tri
ca
l par
ts
Check the power supply voltage [V] as illustrated on the compressor service manual
•
Check that the terminals of the power supply cables to the compressor are correctly fixed
•
Check for any melted or blackened points on the power cables
•
Check that the current value [A] is as specified in the rating plate data
•
Check the value of the direct current after the SCR (refer to service manual)
•
Check the value of the voltage [V] on the storage condensers (refer to the compressor
service manual)
•
Replace the 4 storage condensers
every 5
years
Check the correct operation of the safety systems (alarms)
•
Apply the insulating grease and lanolin as indicated in section 6.1 of the centrifugal
compressor maintenance manual
•
C
hec
ks
on
el
ec
tri
ca
l par
ts
Check that all the communication cables between the compressor and its components are
correctly fixed
•
Check that all the electronic devices are well fixed into their housing and position
•
Visually check that all the printed electronic cards (e.g. backplane, interface module,
BMCC etc.) do not have any signs of burning or damage
•
Visually check that all the printed electronic cards (e.g. backplane, interface module,
BMCC etc.) are not dusty or dirty at all Otherwise clean with suitable tools
•
Check that the temperature and pressure sensor readings are correct; otherwise replace
the component
•
Type of belt
Minor pulley diameter
(mm)
Minor pulley speed
(rpm)
Min. F’ (Newton)
Max. F” (Newton)
