Table of Contents
Advertisement
information on the condition of the machine. It is therefore important to
check the insulation resistance and the polarization index at the following
times:
• Before starting up a machine for the first time
• After an extended period in storage or downtime
• Within the scope of maintenance work
The following information is provided regarding the state of the winding
insulation:
• Is the winding head insulation conductively contaminated?
• Has the winding insulation absorbed moisture?
As such, you can determine whether the machine needs commissioning or
any necessary measures such as cleaning and/or drying the winding:
• Can the machine be put into operation?
• Must the windings be cleaned or dried?
Detailed information on testing and the limit values can be found here:
"Testing the insulation resistance and polarization index" (Page 18)
2.4.3.2
Lubricating the rolling bearings
If you correctly store the machine for a longer period of time, it can be
assumed that within a period of two years, the grease in the bearings will
not deteriorate.
• For motors with thermal class 155, for normal ambient temperatures,
use a lithium-soap rolling bearing grease with a melting point of at least
180 ºC.
• For machines with thermal class 180, and for certain special machines,
use the special grease specified on the machine lubricant plate.
2.4.3.3
Regreasing rolling bearings after storage periods of up to two years
• For machines with regreasing systems, briefly lubricate both bearings
after commissioning with the machine running as a precautionary
measure.
• Grease type, grease quantity and relubrication intervals for the regreasing
system are stamped on the rating plate attached to the machine.
75
Advertisement
Table of Contents
