Bosch rexroth CytroBox Operating Instructions Manual page 114

114/128 Troubleshooting
Error
Drive overtemperature
Hydraulic fluid temperature
too high
Increased filter
contamination
Breathing filter contaminated Contaminated ambient air
Bosch Rexroth AG, CytroBox, RE 51057-B/11.19
Possible cause
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
Cooling water valve does not switch.
Insufficient cooling power of hydraulic fluid.
Faulty 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.
External heat input 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.
Cooling water valve is not opened.
Switching threshold of the oil temperature
is set too high.
Protective motor switch of the recirculation
motor has triggered.
Deposition of dirt due to insufficient
cleaning of components during installation.
Deposition of dirt during filling of hydraulic
fluids.
Abrasion at components
Remedy
▶ Make sure that the coolant complies with the
requirements of the technical specifications.
▶ Check the cooling water valve for its function.
– Make sure that the lamp on the valve connector is
illuminated.
– Dismantle the rear side of the hydraulic cabinet to
this end.
▶ Calculate the heat input 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 contact the Bosch Rexroth
customer service to install an external oil cooling,
if necessary.
▶ Check if the cooling circuit is starting up.
The parameter P-0-1411, Status word of special
functions Bit 9, indicates whether the oil cooling is
active (see also chapter 5.3.5 on page 37).
▶ Make sure that the pressure relief valve is set 10 bar
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 work and replace affected
components as necessary.
▶ Make sure that the cooling water valve is opened
(lamp on the valve connector is illuminated).
▶ For information, refer to chapter 5.3.5 on page 37.
▶ Switch off the protective motor switch for the
recirculation motor.
▶ Flush the system and replace the filter element.
▶ Fill the hydraulic power unit via a filling unit with
integrated filter.
▶ Make sure that all components are operated
according to their specifications.
▶ Clean or replace the breathing filters for the tank,
control cabinet and hydraulic cabinet, see Table 50
"Spare and wear parts".