Bosch Rexroth CytroPac Operating Instructions Manual page 71

Table 11: Impact of defects
Error
Frequency converter over-
current when connecting
hydraulic actuators.
Drive overtemperature
The hydraulic fluid
temperature is too high
Increased filter
contamination
Filling and breathing filter
contaminated
Filling level not in the
specified range
Possible cause
Motor current during acceleration too
high.
Insufficient cooling water flow, cooling
water temperature too high, insufficient
cooling water in the system, inlet pressure
too low or deposits in the heat exchanger.
Insufficient cooling power of hydraulic
fluid.
Incorrect and usually too low pressure
valve setting.
A part of the pump delivery volume is
returned back to the oil tank via the
pressure relief valve.
Extreme heat introduction into the
hydraulic fluid.
Insufficient cooling water flow, cooling
water temperature too high, insufficient
cooling water in the system, inlet pressure
too low or deposits in the heat exchanger.
Increased efficiency losses due to changed
conditions including wear.
Deposition of dirt due to insufficiently
cleaning of components during
installation.
Deposition of dirt during filling of
hydraulic fluids.
Abrasion at components.
Contaminated ambient air.
Leakage
Oscillating volume too high
Water ingress
Remedy
▶ Extend the acceleration ramp E0.26.
▶ Make sure that the coolant complies with the
requirements of the technical specifications.
▶ Calculate the heat introduction in the hydraulic
system, e.g. by calculation of the hydraulic power
loss of valves, rotary transmission leadthrough, etc.
▶ Compare the results with the selected oil cooling
power of the hydraulic power unit.
▶ Reduce the cooling water temperature, increase
the cooling water flow or replace the hydraulic
power unit against a model with higher oil cooling
power.
▶ Make sure that the pressure relief valve is set
10 % over the operating pressure.
▶ Check whether external heat sources are
positioned too close to the hydraulic system.
▶ If necessary, separate the heat sources from the
hydraulic system.
▶ Make sure that the coolant complies with the
requirements of the technical specifications.
▶ Carry out maintenance and replace affected
components as necessary.
▶ Flush the hydraulic system.
▶ Fill the hydraulic system via a filling unit with
integrated filter.
▶ Make sure that all components are operated
according to their specifications.
▶ Clean or replace the breathing filter, see table
10 "Spare and wear parts".
▶ Check and correct the cause for the loss of
hydraulic fluid.
▶ If necessary, refill hydraulic fluid (also refer to the
error "Pressure fluctuations in the pressure line").
▶ Make sure that the sum of the required oscillating
volume of the plunger or differential cylinder
complies with the specifications of the hydraulic
power unit.
▶ Check the function of the externally installed heat
exchanger.
CytroPac, RE 51055-B/06.17, Bosch Rexroth AG
Troubleshooting 71/84