Maintenance; Preparations For Maintenance; Bearings - Siemens 1LA8 Series Operating Instructions Manual

6

Maintenance

6.1 Maintenance

6.1.1 Preparations for maintenance

Instructions relevant for safety
Warning
Before starting any work on the motor or other
equipment, particularly before opening covers
over live or moving parts, the motor must be
properly isolated from the power supply. Besides
the main circuits, any additional or auxiliary
circuits that may be present must also be isolated
especially the anti-condensation heating.
The "5 Safety rules" to be followed are:
– Isolate the equipment
– Take effective measures to prevent
reconnection
– Verify equipment is dead
– Ensure proper earthing connections
– Cover or fence off adjacent live parts
The precautions listed above should remain in
force until all maintenance work is finished and
the motor has been fully assembled.
Certain parts of the motor may reach
temperatures above 50°C.
When cleaning the motor with compressed air,
ensure that suitable exhaustion measures are
used and you use personal protective gear
(goggles, face mask/filter or similar)!
If chemical cleaning agents are used, observe
the instructions and any warnings.
Chemical agents must be compatible with the
motor's components/parts, especially when it
involves plastics.
Caution
(Environmental Protection)
The disposal of waste generated during operation
& maintenance of the motor should be done as per
the applicable local environmental legislations.
Caution
(Environmental Protection)
Waste Copper windings during repair and
maintenance - to be collected as segregated
waste and sent to registered recyclers approved
by the respective State Pollution Control Board.
20
Note
Operating conditions and characteristics can vary
widely. For this reason, only general maintenance
intervals can be specified here.
Note
Where motors are fitted with plugged drain holes,
these should be opened from time to time to allow any
accumulated condense water to be drained away.
Condense water openings should always be at the
lowest point of the motor!
General
Periodic overhauling of the motor is recommended to
ensure long trouble free service.
Before starting the maintenance work, make sure that
the supply is disconnected. These motors are provided
closely pitched ribs for effective cooling of the motor.
These ribs should be cleaned at regular intervals either
by oil free compressed air, or by scraping, depending
on the level of contamination.
The inside of the motor should be cleaned using dry
compressed air during normal overhauling of the
motor. Special care should be taken while cleaning the
windings to remove loose dust, moisture etc.

6.1.2 Bearings

Bearing and lubrication
All motors, as a standard feature, are provided with
floating bearing at Non-drive end and fixed bearing at
Drive end. All motors are provided with regreasing
arrangement (grease nipples).
Grease types
The regreasing intervals and the grease types are
stated on the lubrication instruction plate of the
motor. The motor must be regreased at least once
every 12 months. The greasing instructions can be
found on the lubrication instruction plate.
For standard applications, the initial greasing of the
bearings is usually done with a grease suitable for
temperature range from –20°C to 130°C. If the motors
have been ordered for the extended operating
temperature range below -20°C or above 130°C, the
permissible grease type is specified on the lubrication
data plate.
Unirex N3 of Exxon Mobil is the grease used in
Siemens motors. This grease has Lithium soap as
thickening agent and mineral oil as the basic oil.