WEG WGM20 Series, Installation, Operation & Manintenance Manual

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14108242 Installation, operation and maintenance manual – Squirrel cage motor – WGM20 Line l 37
The excess of grease exits through the lower bearing drain
and deposits in the grease reservoir.
NOTE
It is not necessary to remove old grease from
the reservoir at each relubrication. When the
reservoir is full, disassemble it, discard the
old grease in an appropriate location and
reassemble it, as shown in Figure 7.5.
Grease reservoir
Figure 7.5: Grease reservoir
7.10.4 Type and amount of grease
The relubrication of the bearings must always be done
with the original grease, specified on the bearing
nameplate and in the documentation of the motor.
ATTENTION
WEG does not recommend the use of
greases different from the motor original
grease.
It is important to perform a correct lubrication, i.e., to
apply the correct grease and in the proper quantity,
because either poor or excessive lubrication will damage
the rolling bearings.
Excessive amount of grease cause temperature increase,
due to the great resistance it offers to the movement of
the bearing rotating parts. Consequently, due to the
heating, the grease can completely lose its lubricating
characteristics.
7.10.5 Alternative greases
If it is not possible to use the original grease, alternative
greases listed in Table 7.4 can be used, under the
following conditions:
1.
The motor speed must not exceed the limit speed of
the grease, according to the type of rolling bearing, as
informed in Table 7.5 and table 7.6;
2. The bearing lubrication interval must be corrected by
multiplying the interval informed on the bearing
nameplate by the multiplication factor informed in
Table 7.4;
3. Use the correct procedure to change the grease,
according to section 7.10.6 of this manual.
Table 7.4: Options and characteristics of the alternative greases
for regular applications
Manufacturer Grease
Constant
operating
temperature
(°C)
Multiplication
factor
Exxon Mobil
UNIREX N3
(Lithium Complex
Soap)
(-30 to +150) 0.90
Shell
ALVANIA RL3
(Lithium Soap)
(-30 to +120) 0.85
Petrobras
LUBRAX
INDUSTRIAL GMA-2
(Lithium Soap)
(0 to +130) 0.85
Shell
STAMINA RL2
(Diurea Soap)
(-20 to +180) 0.94
SKF
LGHP 2
(Polyurea Soap)
(-40 to +150) 0.94
The Table 7.5 and the Table 7.6 show the types of rolling
bearings for the horizontal and vertical motors, the amount
of grease and the rotation limit of use the optional
greases.
Table 7.5: Optional greases application - horizontal motors
GREASE LIMIT ROTATION [rpm] – Horizontal Motors
Rolling bearing
6222 6224 6228 6232 7222
Stamina RL2
1800 1800 1800 1800 1800
LGHP 2 1800 1800 1800 1800 1800
Unirex N3 1800 1800 1800 1500 1800
Alvania RL3 1800 1800 1800 1200 1800
Lubrax Industrial
GMA-2
1800 1800 1500 1200 1800
Table 7.6: Optional greases application - vertical motors
GREASE LIMIT ROTATION [rpm] – Vertical Motors
Rolling bearing 6222 6224 6226 6232 7222
Stamina RL2 1800 1800 1800 1800 1800
LGHP 2
1800 1800 1800 1800 1800
Unirex N3
1800 1800 1800 1800 1800
Alvania RL3 1800 1800 1800 1500 1800
Lubrax Industrial
GMA-2
1800 1800 1500 1200 1800
7.10.6 Procedure for changing the grease
In order to replace the POLYREX EM103 grease by one
of the alternative greases, the bearings must be opened to
remove the old grease and then filled with the new grease.
If it is not possible to open the bearings, the old grease
must be purged by applying new grease until it begins to
appear in the exit drawer with the motor running.
In order to replace the STABURAGS N12MF grease by
one of the alternative greases, you must first open the
bearings, completely remove the old grease, and then fill it
with new grease.
ATTENTION
Since there is no grease compatible with
STABURAGS N12MF, other grease must
not be injected in the attempt to purge it. This
procedure will not expel completely the old
grease and they will mix, which may cause
damage to the bearings.