Servicing The External Fan - Siemens HT-direct Operating Instructions Manual

Maintenance
6.1 Maintenance
To remove the spent grease, loosen the outer bearing cap. Escaping oil at the bearing or
grease escaping during regreasing is an indicator that the space for the spent grease has
been over-filled. [ID 1144.00]
6.1.4

Servicing the external fan

Preparatory steps
Before starting the maintenance work on the fan, and in particular before opening the
terminal box, disconnect the device from the mains supply and secure it so that it cannot be
switched back on.
Fan
The fan is essentially maintenance-free. Only dirt and dust deposits on the impeller and
motor, in particular in the gap between the impeller and the inlet nozzle, can impair the
function of the fan, which is why they should be cleaned at regular intervals (the intervals
depend on how much dirt/dust is present). In doing this, make sure that the impeller is
cleaned evenly, as irregular deposits can lead to an imbalance.
Separate fan motor
Perform an occasional visual inspection of the separate fan motor and check it electrically
and mechanically every time the ball bearings are replaced. The rolling-contact bearings of
the motor are greased for life and should be replaced after no more than 40,000 hours of
service or 5 years. [ID 621]
74
bearing. The bearing temperature rises sharply at first, then drops to the normal value
again when the excess grease is displaced out of the bearing.
CAUTION
Limited holding capacity of the spent grease chambers
The spent grease chambers of the rolling-contact bearings only hold the spent grease
from approximately 10 regreasing procedures. Escaping oil at the bearing or oil
escaping during regreasing is an indicator that the space for the spent grease is full.
When the spent grease chamber is full, the spent grease must be removed before the
regreasing procedure, otherwise it will escape into the interior of the motor.
WARNING
A5E01083943A AB
Siemens AG Operating Instructions 2.02 1FW4