16 | Flameproof motors
way keeping the winding insulation resistance within
acceptable levels.
The space heaters of the motor must
be mandatorily energized when the
motor is stored in local with
temperature < 5 °C and relative air
humidity > 50%.
3.7.6. INSULATION RESISTANCE
During the storage period, the winding insulation
resistance of the motor should be measured
according to item 3.5 of this manual and registered
every 3 months and before the motor installation.
Eventual drops in the insulation resistance level
must be investigated.
3.7.7. EXPOSED MACHINED SURFACES
At factory, all exposed surfaces (for example, the
shaft edge and flanges) are protected with a
temporary protective agent (rust inhibiter).
This protective coating should be reapplied every 6
months at least. When this coating is removed
and/or damaged, the same preventive action must
be done.
RECOMMENDED PRODUCTS
- Anticorit BW 366, Manufacturer: FUCHS.
- Dasco Guard 400 TX AZ, Manufacturer:
D.A.Staurt.
- Tarp, Manufacturer: Castrol.
- Tectyl 511-M, Manufacturer: Valvoline.
3.7.8. FLAMEPROOF JOINTS
For motors with protection “d”, all the surfaces of
flameproof joints shall be verified with special care
to assure that all the machined surfaces of
flameproof joints are properly protected with a
corrosion inhibiting grease.
Before the assembly of any part of motor or terminal
box enclosures, the surfaces of flameproof joints
shall be protected against corrosion with protective
grease.
AUTHORIZED PRODUCTS
- Polyrex EM, Manufacturer: MOBIL.
- Molycote 33, Manufacturer: Dow Corning
Corporate.
- Lumomoly PT/4, Manufacturer: Lumobras.
3.7.9. BEARINGS
3.7.9.1 ANTIFRICTION BEARINGS
LUBRICATED BY GREASE
The bearings are lubricated at the factory to perform
the motor tests.
During the storage period, every two months is
necessary to remove the shaft locking device and
turn the shaft manually to conserve the bearing in
good conditions. After perform the shaft rotation,
this one shall be turned at 45º from the original
position.
After 6 months of storage and before starting in
operation, the bearings should be regreased, as
item 8.2.7 of this manual.
If motor is kept in storage for approximately 2 years
or more, the bearings must be inspected and
regreased according to item 8.2 of this manual.
3.7.9.2 SLEEVE BEARINGS
Motors with sleeve bearings are always transported
without oil inside the bearings.
The motor must be stored in its original operation
mounting position and with oil inside the bearings
(see oil quantities in the Table 8-17).
The oil level should be respected, remaining in the
midle of the oil sight glass.
During the storage period, every two months is
necessary to remove the shaft locking device and
rotate at about 30 rpm for the oil circulation and to
conserve the bearing in good conditions.
If it is not possible to rotate the shaft of the motor,
the follow procedure should be used to protect
internally the bearing and the contact surfaces
against corrosion:
- Drain the whole bearing oil;
- Dismantle the bearing, following the procedure
described in the item 8.2.10.3 of this manual;
- Clean the bearing;
- Apply the anti-corrosive (ex.: TECTIL 511 or
equivalent) inside the bearing, bearing line (top
and bottom half) and in the shaft contact surface
of the motor;
- Assemble the bearing, following the procedure
described in the item item 8.2.10.4 of this
manual;
- Close all tapped holes with screw plugs;
- Seal the gaps between the shaft and bearing
seal, and between bearing seal and bearing
housing by using self-adhesive permanent tape;
- Connecting flanges (Ex.: Oil inlet and outlet)
must be covered with blank plates.
- Remove the bearing top sight glass and spray
the corrosion inhibitor on the bearing.
- Put some desiccant (silica gel) inside of the
bearing. The desiccant absorbs the humidity and
prevents the formation of moisture and water
condensation inside the bearing.
To Next Page
Loading...
