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6 MAINTENANCE
Maintenance procedures must be performed so as to ensure the proper performance of the equipment. The frequency of
the inspections will largely depend on the application local conditions and operating conditions.
Failure to comply with one of the items listed below may lead to the reduction of the alternator life, unnecessary stops and/or
damage to the facilities.
6.1 EMERGENCY GENERATOR
GROUPS
To ensure reliability and maintenance of the insulation
level, alternators used in emergency generators must be
placed in operation and, if possible, receive load 2 to 3
hours each month.
6.2 CLEANING
The frame, multi-leaf dampers, grids and fan covers must
be kept clean, without accumulation of oil or dust on the
outside to facilitate the heat exchange with the
environment.
Also, the inside of the alternators must be kept clean and
free of dust, debris and oil. In order to clean them,
brushes or clean cotton rags must be used. If the dust is
not abrasive, an air gun must be used to blow the dirt off
from the fan cover and eliminate all the accumulation of
dust contained on the fan blades and frame.
The debris impregnated with oil or humidity can be
cleaned with cloth moistened in a suitable solvent.
The terminals in the terminal box must be clean, free of
rust, in perfect mechanical condition and without deposits
of grease or verdigris.
6.3 NOISE
The noise must be observed daily. In case of anomalies,
the alternator must be stopped and the causes must be
investigated and corrected.
6.4 VIBRATION
Maximum vibration level for the alternator under load: 20
mm/s (RMS), according to standard ISO-8528.
6.5 BEARINGS
The temperature control on the bearings is also part of
routine maintenance of the alternators.
The temperature can be controlled permanently with
thermometers placed outside the bearing, or through
thermoresistances.
The alarm and shutdown temperatures for the bearings
can be adjusted respectively for 110 °C and 120 °C.
6.5.1
Lubrication
The bearings must be relubricated annually or according
to the lubrication intervals reported on the nameplate of
the bearings fixed on the alternator and to the technical
documentation, prevailing whichever occurs first.
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Installation, operation and maintenance manual
6.5.1.1
Type and amount of grease
The relubrication of the bearings must always be made
with the original grease, specified on the bearing
nameplate and the documentation of the alternator.
ATTENTION
1. When the bearing is opened, inject the
new grease through the grease nipple to
expel the old grease found in the grease
input tube and insert the new grease in
the bearing, in the inner ring and outer
ring, filling ¾ of the empty spaces.
2. Never clean the roller with cotton-based
cloths, because they leave some lint as
solid particles.
3. It is important to perform a proper
lubrication, that is, to apply the grease
correctly and in a suitable quantity,
because both poor lubrication and
excessive lubrication adversely affect the
bearing.
NOTE
WEG is not responsible for the change of
grease or for any damages arising from the
exchange.
6.5.1.2
Instructions for lubrication
NOTE
The data of the rolling bearings, quantity
and type of grease and lubrication intervals
are informed in a nameplate fixed on the
alternator. Check this information before
performing the lubrication.
The lubrication system is designed in such a way that
during the relubrication of the bearings, all the old grease
is removed from the rolling bearings tracks and expelled
through a drain, which enables the exit, but prevents the
entering of dust or other harmful contaminants.
This drain also prevents damage to the bearings by the
well-known problem of excessive lubrication.
It is advisable to perform the lubrication with the alternator
in operation, to ensure the renewal of grease in the
bearing housing.
If this is not possible due to the presence of rotating parts
near the nipple (pulleys, etc.), which can put the operator
in danger, proceed as follows:
With the alternator stopped, inject approximately half
the total amount of grease recommended and operate
the alternator for approximately 1 minute at full speed;
Stop the alternator and inject the remaining grease. The
injection of all grease with the alternator stopped may
cause penetration of the lubricant into the alternator.
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