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Maintenance and repair
Bosch Rexroth AG
, CytroPac, RE 51055-B/02.2021
10.5.3 Monitoring of the oil temperature
The oil temperature is monitored via an integrated fill sensor with two switching
points (warning and shutdown). In "Basic" configuration, it must be evaluated by the
machine control, and shutdown of the hydraulic power unit must be ensured if the
shutdown temperature is exceeded.
Possible causes for temperature increase include:
• Heat exchanger malfunction
• Change in cooling water conditions
• Malfunction or incorrect setting of pressure valves
(e.g. maximum pressure limit, pump controller, pressure reducing valve)
• Fault of the pump (wear, increased leakage)
• Changed environmental conditions (e.g. increased ambient temperature)
• Changed load conditions at drives
In case of inadmissible temperature increases, the causes must be determined and
corrected.
10.5.4 Filter element clogging monitoring (return flow filter)
Be critical if the filter clogging sensors do not indicate any change over multiple
inspection intervals. Of course, this may always be an indicator that the hydraulic
fluid is clean. However, it may also have the following causes:
– The clogging indicator is defective.
– The filter element is defective.
Plan and carry out replacement of the filter element at the end of the shift.
Shorten the intervals between the required replacement of filter elements, identify
the cause of the deposition of dirt and correct it.
Proceed as described.
1.
Before starting to work, provide receptacles for the hydraulic fluid and the filter
element.
2.
Depressurize the hydraulic power unit and secure it against unintentional start-
up.
3.
Fold out the spring clip with a screwdriver or similar.
4.
Remove the filter cover.
5.
Pull the filter element out with the clip.
6.
Insert a new filter element (see chapter 17.4 “Accessories“ on page 68).
7.
Put the filter cover back on.
8.
Slide the spring clip with a screwdriver into the locking position of the filter
cover.
9.
Dispose of the filter element in accordance with national or company-specific
regulations.
Possible causes for
temperature increase
Action:
Exchanging the return flow
filter element:
