Manual for Induction Motors and Generators
46 -
Commissioning and Start-up
3BFP 000 050 R0101 REV E
5.5.2.2 Resistance temperature detectors
Recommended maximum temperature settings:
For determining the temperature settings, see the Connection Diagram delivered with the
machine. It is recommended to apply the method described in
when
setting the temperature alarm.
5.5.2.3 Thermistors
If the machine is equipped with thermistors (PTC), the operating temperature of the thermistors
is found on the Connection Diagram. The operating function can be chosen to be an alarm or a
trip signal. If the machine is equipped with six thermistors, both alarm and trip signals can be
used respectively.
5.5.3 Bearing temperature control
5.5.3.1 General
The bearings can be equipped with temperature detectors for monitoring the bearing
temperatures. The viscosity of the grease or oil used will become smaller as a function of higher
temperature. When the viscosity falls below a certain limit, the ability to form a lubricating film
inside the bearing will cease, and the bearing will fail, and possibly, shaft damage will occur as
a result.
If the machine is equipped with resistance temperature detectors, the temperature of the
bearings should preferably be monitored continuously. If the temperature of a bearing
unexpectedly starts to rise, the machine should be shut down immediately, as the temperature
rise might indicate a bearing failure.
5.5.3.2 Resistance temperature detectors
Recommended maximum temperature settings:
For determining the temperature settings, see the Connection Diagram delivered with the
machine. It is recommended to apply the method described in
when
setting the temperature alarm.
5.5.3.3 Thermistors
If the rolling bearings are equipped with thermistors (PTC), the operating temperature of the
thermistors is found on the Connection Diagram. The operating function can be chosen to be an
alarm or a trip signal. If the rolling bearings are equipped with two thermistors, both alarm and
trip signals can be used respectively.
5.5.4 Protection equipment
The machine has to be protected against various disturbances, faults and overloading that might
damage the machine. The protection must be in accordance with the instructions and regulations
for each country where the machine is used.
