Bosch Rexroth REFUspeed RS51

Questions and Answers

E
eriosAug 19, 2025
What to do if the Bosch Rexroth REFUspeed RS51 shows a 'DC link voltage too high' error?
- J
  John FriedmanAug 19, 2025
  If the fault occurs during braking, try setting the ramp-function generator down ramp slower using parameter P0280. Also, inspect the brake resistor (if option W is enabled) with an ohmmeter and consider using a higher-rated external brake resistor. Ensure the brake resistor is properly selected via parameter P0036.
L
Larry HollandAug 21, 2025
How to fix a Bosch Controller drive overtemperature issue?
- M
  Mary MartinezAug 22, 2025
  To resolve a 'Drive overtemperature' fault in your Bosch Controller, first, be aware that an alarm triggers above 65 °C, and shutdown occurs beyond 70 °C. This temperature range can be adjusted using parameter P0086. Monitor the heatsink temperatures using monitors D1870 (power section) and D2029 (rectifier). If the ambient temperature exceeds 40 °C, or if the fan is defective or the air filter is blocked, address these issues. If the fan control is incorrectly configured, for example, set to “Automatic” with an excessively high threshold in P0035, reduce the threshold.
J
justin04Aug 23, 2025
What causes the Bosch Rexroth REFUspeed RS51 brake resistor to overload, and how can I resolve it?
- C
  Chelsea HoAug 25, 2025
  To troubleshoot a 'Brake resistor overload' error on your Bosch Controller, examine the brake resistor itself. Ensure that, if option W is enabled, the resistor's ohmic value is not excessively high and that a brake resistor is indeed connected. Verify that the connected brake resistor is adequately sized for the energy being fed back into the DC link during braking. Also, check the down-ramp setting in P0280.0X and confirm that the correct brake resistor was selected in P0038. Refer to parameters P0623 through P06256 for values and adhere to maximum braking duration and no-load times between braking operations, consulting the load diagram for the brake resistor option.
A
Abigail DavisAug 26, 2025
What to do if my Bosch Rexroth REFUspeed RS51 Controller displays a 'DC link voltage too low' error?
- M
  Marilyn HillAug 26, 2025
  To address a 'DC link voltage too low' error on your Bosch Controller, use an oscilloscope to check the line supply voltage. The cause may be line supply dips, a power failure, an interrupted main contactor contact, or a defective line rectifier. During operation the DC link voltage falls below the limit value V (P0094).
P
Patrick RobinsonAug 28, 2025
What to do if Bosch Rexroth REFUspeed RS51 displays 'Analog input: I < 4 mA' error?
- M
  matthewharveyAug 28, 2025
  To fix the 'Analog input: I < 4 mA' error on your Bosch Controller, check the setpoint line for short-circuits or cable breaks, particularly on the analog input or optional analog inputs, specifically when using operating modes 4-20 mA or 2-10 V. Also, verify the response type in P0564.0X or P0752.0X and the operating mode in P0201.0x or P0735.0X.
J
Jonathan KnightAug 30, 2025
Why does my Bosch Rexroth REFUspeed RS51 Controller show an 'External' fault and how can I clear it?
- J
  Jimmy BurnsAug 30, 2025
  To address an 'External' fault on the Bosch Controller, determine and eliminate the cause of signal loss in the plant or system. This fault occurs in a fail-safe version if a digital input assigned the “No external fault” function lacks a 24 V signal.
K
Kevin RogersSep 1, 2025
What should I check if the Bosch Controller reports a main contactor fault?
- D
  David GibbsSep 1, 2025
  To resolve a 'Main contactor' issue on your Bosch Controller, check the control voltage for the main contactor and the auxiliary contact used for the checkback signal. The main contactor does not pull-in during operation, or a checkback signal is not received from it.
C
Caitlin MartinezSep 3, 2025
What could cause a Bosch Rexroth REFUspeed RS51 to fail during pre-charging?
- V
  Veronica WiseSep 3, 2025
  To troubleshoot a 'Pre-charging' fault on your Bosch Controller, ensure the line supply voltage is present and check for short-circuits between terminals C and D, or between C-PE and D-PE. If using option W, inspect for short-circuits between F and C. For option V, ensure the 'On' command wasn't connected while the standby supply is active without line supply voltage. After acknowledging the fault, wait 30 seconds before powering up again to protect the pre-charging resistors. After the drive has been powered-up, the DC link voltage charging over time is monitored. If illegal deviations occur, pre-charging is stopped.
S
shermananthonySep 5, 2025
What does 'Internal WS comm' mean on my Bosch Rexroth REFUspeed RS51 and how do I fix it?
- E
  ericvelazquezSep 5, 2025
  To address an 'Internal WS comm.' fault in your Bosch Controller, first, check the plug connection between the PC boards. If the issue persists, consider replacing the modules. Communications between the processor board and the power section are faulted.
T
Tony RichardsSep 8, 2025
How do I fix an 'NTC power section' error on a Bosch Rexroth REFUspeed RS51?
- S
  Sierra NelsonSep 8, 2025
  To resolve an 'NTC power section' fault in your Bosch Controller, inspect the plug connector for the NTC on the heatsink in the power section or rectifier. Replace the connector, cable, or NTC if necessary. Check for excessive resistance (high ohmic connection) or a missing contact. The cause may be a wire broken/interrupted to the NTC on the heatsink in the power section or rectifier; NTC defective.