Instructions For Lubrication; Procedures For Relubrication Of Bearings; Bearings Replacement; Alternator With Single Bearing - B15T - WEG G Serie Manual De Instalación, Operación Y Mantenimiento

NOTE
WEG is not responsible for the change of
grease or for any damages arising from the
change.

6.5.1.2 Instructions for lubrication

The lubrication system is designed such that during
relubrication of bearings, all of the old grease is removed
of bearings and expelled through a tube which enables the
output of the same, but prevents the entry of dust or other
hazardous contaminants into the bearing.
This drain also prevents damage to the bearings due to
the well-known problem of excessive relubrication.
It is advisable to perform relubrication with the alternator in
operation, so as to ensure the renewal of grease in the
bearing housing.
If this is not possible due to the presence of parts near the
grease nipple (pulleys etc.), which can jeopardize the
physical integrity of the operator, proceed as follows:

With the alternator stopped inject approximately half the
total amount of grease planned and operate the
alternator for approximately 1 minute at full speed;

Stop the alternator and inject the remaining grease.
Injection of all grease with the alternator stopped can
cause penetration of the lubricant to the inside of the
alternator.
ATTENTION
It is important to clean the grease cups prior to
lubrication, to prevent foreign material from
being drawn into the bearing.
NOTE
The data of bearings, quantity and type of
grease and lubrication intervals are reported
in an identification plate fixed on the
alternator. Verify this information before
making lubrication.

The lubrication intervals informed in the plate consider a
working temperature of the bearing of 70°C.

Based on the operating temperature ranges listed
below, apply the following correction factors for
lubrication intervals of bearings:

Operation temperature lower than 60 °C: 1,59
 Operation temperature from 70 °C to 80 °C: 0,63

Operation temperature from 80 °C to 90 °C: 0,40

Operation temperature from 90 °C to 100 °C: 0,25

Operation temperature from 100 °C to 110 °C: 0,16
10680382 Installation, operation and maintenance manual – Synchronous Alternator – G line - Horizontal

6.5.1.3 Procedures for relubrication of bearings

1. Remove the cover of the drain;
2. Clean with a cotton cloth around the grease cup hole;
3. With the alternator running, inject grease until new
grease begins to flow from the drain or until the
amount of grease informed in Table 6.1 has been
introduced;
4. Operate the alternator long enough so that excess
grease flow through the drain;
5. Inspect the bearing temperature to make sure that
there was no significant change;
6. Replace the cover of the drain.
6.5.2

Bearings replacement

ATTENTION
For security, the bearings replacement must
be done with the alternator disconnected
from the driving machine.

6.5.2.1 Alternator with single bearing - B15T

Frame 160 and 200
1. Put the alternator in a vertical position with the side of
the coupling discs to the top;
2. Remove the whole rotor, preferably with an eyebolt
having the same thread of the center hole of the shaft
end, increasing it with the use of a hoist;
3. Replace the bearing and replace the complete rotor,
making sure that the O-ring is in position at the hub of
the back cover.
Frame 250
1. Release the cables of the exciter (F+) e (F-).
2. Remove the cover and multi-leaf damper to access the
rear bearing and perform the exchange.
Frames 315 and 400
To disassemble the rear of the alternator and have access
to the bearing, follow the instructions below:
1. Release cables (F+) and (F-) in the terminal box;
2. Remove back multi-leaf damper;
3. Remove the cables of the main rotor connected to the
rectifier bridge of the exciter rotor;
4. Remove the screws that hold the exciter rotor shaft
and remove it manually;
5. Remove the screws of the back cover attached to the
frame and remove this cover along with the exciter
stator;
6. Replace the bearing and assemble the alternator.

6.5.2.2 Alternator with double bearing - B35T

To perform the exchange of the bearings in the alternator
with double bearing, it is necessary to disassemble the
alternator entirely.
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