BEARING LUBRICATION
Bearing life is assured by maintain-
ing proper alignment, proper belt or
chain tension, and good lubrication
at all times.
Prior to shipment, motor bearings
are lubricated with the proper
amount and grade to provide six
months of satisfactory service
under normal operating conditions.
For best results, grease should be
compounded from a polyurea base
and a good grade of petroleum oil.
It should be of No. 2 consistency
and stabilized against oxidation.
Operating temperature range
should be from -15°F to +300°F for
class F and H. Most leading oil
companies have special bearing
grease that is satisfactory.
Re-lubricate bearings every six
months (more often if conditions
require) as follows:
1. Stop the motor. Lock out the
switch.
2. Thoroughly clean off pipe plugs
and remove from housings.
3. Remove hardened grease from
drains with stiff wire or rod.
4. Add grease to inlet until small
amount of new grease is forced
out of the drain.
5. Remove excess grease from
ports, replace inlet plugs, and run
motor 1/2 hour before replacing
drain plugs.
6. Put motor back in operation.
INSULATION RESISTANCE
Check insulation resistance periodi-
cally. Any approved method of mea-
suring insulation resistance may be
used, provided the voltage across
the insulation is at a safe value for
the type and condition of the insula-
tion. A hand-cranked megger of not
over 500 volts is the most conve-
nient and safest method. Standards
of the Institute of Electrical and
Electronics Engineers, Inc. (IEEE)
recommend that the insulation
resistance of stator windings at
75°C, measure at 500 volts DC,
after one Minute should not be less
than:
Rated Voltage of
Insulation
M 1000 = resistance
in
1000 Megohms
This formula is satisfactory for most
checks. For more information, see
IEEE Standard No.43,
“Recommended Practice for
Insulation Resistance Testing of AC
Rotating Machinery”
7
CAUTION
Entanglement.
May cause injury or property damage.
To avoid the danger, do not lubricate motor while in operation,
since excess grease will be forced through the bearings and into
the motor before it will force its way out of the drain plug. Excess
grease accumulation on windings reduces the insulation life.
CLEANING
The motor exterior must be keep
free of oil, dust, dirt, water, and
chemicals. For fan cooled motors, it
is particularly important to keep the
air intake openings free of foreign
material. Do not block air outlet or
inlet.
On non-explosion proof TEFC
motors, a removable plug in the
bottom of the motor bearing hous-
ing permits removal of accumulated
moisture. Drain regularly.
SERVICE
For immediate action on your motor
problems, call your certified service
center or contact your nearest
Siemens District Office.
WARNING
Entanglement.
Can cause death, serious injury, or property damage.
To avoid the danger, do not attempt to clean motor while it is
operating. Contact with rotating parts can cause severe
personal injury or property damage. Stop the motor and lock
out switch before cleaning.
