Rexroth IndraDrive fault F8027 indicates Starting Lockout While Drive Enabled. The drive detected activation of the starting lockout while the drive enable signal was already active. It immediately removes motor torque because the two commands conflict.
F8027 Fault Response
The starting lockout inhibits motor operation, while drive enable permits operation. If both states occur simultaneously, the drive becomes torque-free and reports F8027 to prevent unintended motor operation. Treat the loss of torque as the commanded fault response, then diagnose why the conflicting inputs occurred.
Likely Causes
| Area | Possible fault | Inspection focus |
|---|---|---|
| Controller logic | PLC or machine controller activates starting lockout during operation | Command sequence and overlap with drive enable |
| Field wiring | Loose, damaged, incorrect, or shorted wiring | Starting lockout input circuit and terminations |
| Safety devices | Faulty switch, relay, or interlock | Device operation and circuit configuration |
| Input signal | Electrical noise or intermittent operation | Signal stability while the drive is enabled |
| Control hardware | Faulty I/O module or control signal | Input state compared with the commanded state |
Diagnostic and Recovery Procedure
- Review the starting-lockout control sequence. Confirm that the signal cannot activate while drive enable remains active.
- Inspect the starting lockout wiring for loose connections, damage, incorrect termination, or a short circuit.
- Test the associated safety switches, relays, and interlocks. Confirm that each device operates correctly and matches the intended safety-circuit configuration.
- Monitor the starting lockout input for electrical noise or intermittent state changes, especially while the drive is enabled.
- Compare the PLC or controller commands with the actual input states. Correct sequencing errors and investigate any I/O module or control signal that does not follow its command.
- Repair or replace confirmed faulty wiring, switches, relays, interlocks, I/O, or other control components.
- Reset F8027 only after correcting the cause, then verify normal drive operation and confirm that starting lockout no longer overlaps drive enable.
Recurrence Prevention and Verification
Prevent recurrence by interlocking the controller sequence so drive enable is removed before starting lockout activates. Verification must cover both the commanded controller states and the physical input signal; correct logic alone will not detect intermittent wiring, electrical noise, or a failing safety device.
After recovery, confirm that the motor remains torque-free when starting lockout is active and that the drive can return to normal operation only after the conflicting condition has been removed. If F8027 returns, capture the drive-enable and starting-lockout states at the fault transition to distinguish a sequencing error from an intermittent field signal.
FAQ
What does F8027 mean on a Rexroth IndraDrive?
F8027 means Starting Lockout While Drive Enabled. The drive detected starting lockout and drive enable at the same time, removed motor torque, and generated the fault.
Why does an IndraDrive become torque-free during F8027?
The starting lockout inhibits operation while drive enable permits it. Because those commands conflict, the drive immediately removes torque to prevent unintended motor operation.
How do I reset Rexroth IndraDrive fault F8027?
First correct the overlapping commands, wiring defect, intermittent input, failed safety device, or control hardware fault. Then reset F8027 and verify that starting lockout does not activate while drive enable is present.
