38 l
Installation, operation and maintenance manual – Squirrel cage motor – WGM20 Line 14108242
ATTENTION
When the bearing is opened, inject the new
grease through the grease nipple to expel
the old grease found in the grease inlet
tube, and apply the new grease in the
rolling bearing, to the inner and outer
bearing caps, filling 3/4 of the empty
spaces. In case of double bearings (ball
b roller bearing), also fill 3/4 of the
empty spaces between the intermediate
rings.
Never clean the rolling bearing with cotton-
based cloths, because they may release
some lint, working as solid particles.
NOTE
WEG is not liable for the grease change or for
any damages arising from this change.
7.10.7
Low temperature greases
Table 7.7: Grease for application at low temperatures
Manufacturer
Grease
Constant
operating
temperature
(°C)
Application
Exxon Mobil
MOBILITH SHC
100
(Lithium Soap and
Synthetic Oil)
(-50 to +150)
Low
temperature
7.10.8
Grease compatibility
You can say that greases are compatible when the
properties of the mixture are within the property ranges of
the greases individually.
In general, greases with the same type of soap are
compatible; however, depending on the proportion of the
mixture, there might be incompatibility. Therefore, it is not
recommended to mix different types of grease without
consulting the grease supplier or WEG.
Some thickeners and basic oils cannot be mixed, because
they do not form a homogeneous mixture. In this case,
one cannot rule the possibility of hardening or softening of
the grease, or reduction of the dropping point of the
resulting mixture.
ATTENTION
Greases with different types of base must
never be mixed.
For example: Lithium-based greases must
never be mixed with sodium or calcium-
based greases.
7.10.9
Bearing disassembly
Before disassembling the bearing:
Remove the water from the cooling circuit, as described
in item 7.7 of this manual;
Place the motor in the horizontal position (vertical
machines);
Clean the bearing outside completely;
Remove the grounding brush (if any);
Loose the cables of the bearing temperature sensors
on the accessory connection box.
ATENTTION
During the bearings disassembly, care must
be taken to avoid damage the balls, rollers or
shaft surface.
