Siemens SIMOTICS FD 1LL1, Operating Instructions & Installation Instructions

Page: 126 / 188

8.6.3 Avoidance of damage to roller bearings during stoppages
Extended stoppages at the identical or almost identical resting position of the roller bearings
can lead to damage such as brinelling or corrosion, for example.
● During stoppages, regularly start the machine up for a brief period once a month. As a
minimum, rotate the rotor several times.
If you have uncoupled the machine from the driven machine and secured the rotor with a
rotor shipping brace, then remove this before turning the rotor over or starting the machine
up.
Make sure that the resting position of the roller bearings after the rotor has been turned
over is different from what it previously had been. Use the fitted key or the coupling halves
as reference markers.
● During re-commissioning, refer to the information in the "Commissioning" section.
See also
Start-up (Page 105)
8.6.4 Measurement of the insulation resistance after an extended stoppage
Measuring the insulation resistance and polarization index (PI) provides 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 61)
Operation
8.6 Stoppages
SIMOTICS FD 1MH1
126
Operating Instructions 08/2017